The authors would like to thank Ross McLeod, David Torok, Wonsang Kim and Carl Ng for their technical support. M. J. Roy would like to acknowledge the support from EPSRC (EP/L01680X/1) through the Materials for Demanding Environments Centre for Doctoral Training and Rio Tinto Alcan for financial support through a Research Fellowship award.

1. Workpiece Preparation for Forming Trials
<ol>
	<li>Acquire as-cast workpieces machined to the mandrel size such that the inner diameter runout is 0.2 mm, while the outer diameter retains as much cast surface as possible. 
	NOTE: If blanks are drawn from full-size wheel castings, machining operations are required to remove all hub and spoke portions, while providing features which can be employed to clamp the workpiece to the mandrel. This includes removal of the in-board flange.</li>
	<li>Pre-heat a coffin furnace able to receive the entire workpiece to 135 &#176;C, clean the workpiece with degreaser and place in furnace for an hour to prepare for thermal barrier coating application.</li>
	<li>Rapidly remove the workpiece from the furnace, and place on a coating jig. Using an automotive-type paint sprayer, apply a thin layer of thermal barrier die coating to the inner diameter. 
	NOTE: This coating will provide lubrication and reduce heat transfer to the mandrel during forming operations.</li>
</ol>
2. Tooling Preparation
<ol>
	<li>Wipe down the mandrel surface with a damp cloth. Ensure that the mandrel has a total rotational runout of &#60; 0.5 mm using a dial gauge indicator along the forming length. Assess this with a live tooling center engaged on the tailstock plate. Using a torque wrench, ensure that all fasteners aside from those on the clamp assemblies are tightened to specified torque values for Grade 12.9 bolts (in Nm: M8 - 40, M12 - 135, M16 - 340).</li>
	<li>Start the pre-heating system by first powering the gas supply solenoid, and then igniting the torches with a flint spark lighter. Run the pre-heating system for 10 min to expel any condensate collected in the torches/hoses. Extinguish by deactivating the gas supply solenoid.</li>
	<li>Remove any loose/oxidized coating layer on the mandrel with dry 600/P1200 grit silicon carbide paper while turning the mandrel at 20 rotations per minute (rpm).</li>
	<li>Power the on-board data acquisition module, and run the pre-heating system until the thermocouples embedded in the mandrel surface read 200 &#176;C with the live center engaged.</li>
	<li>Using an automotive-type paint sprayer, lightly coat the mandrel surface with a water-based forging lubricant and allow the rotary tooling to cool to ambient temperature with the live tooling center engaged.</li>
	<li>Loosen the jam nut assembly on the roller stand (Figure 3) with a wrench. Set the approach or attack angle on the roller assembly using a toolmaker&#39;s protractor, and tighten both internal and external nuts (M35 - 750 Nm).</li>
	<li>Assemble the 3 clamp assemblies (Figure 4) by first engaging the M12 shoulder bolt to connect element 2 to the clamp bracket. Inspect for any thermal distortion which will prevent element 2 in Figure 4 from smoothly running against the clamp bracket. Ensure that they move freely, lightly sanding the contact surfaces with dry 320/P400 grit silicon carbide paper. Apply a thin layer of high temperature molybdenum-based lubricant with a cloth as needed.</li>
</ol>
3. Forming Operations
<ol>
	<li>Move the roller tool stand completely away from the mandrel towards the spindle, move the tailstock and center to be clear of the mandrel. Manually slide the workpiece onto the mandrel ensuring even engagement. 
	NOTE: As the blanks are nominally axisymmetric, there is no preferred orientation.</li>
	<li>Assemble the clamps onto the mandrel by engaging the tapered die pins and hand tightening M16 bolts running through the mandrel into the clamp blocks. Ensure that there is even pressure being applied by rotating and manually tightening, followed by a pneumatic impact wrench set to 50 Nm.</li>
	<li>Start the heating system and immediately start the mandrel rotating at 20 rpm. Keep applying heat until clamps loosen. For the process considered, this is approximately 3 min. 
	NOTE: This time will be slightly different for each workpiece due to subtle differences in workpiece/mandrel fitment.</li>
	<li>Extinguish the heating system and stop the rotation of the mandrel such that the first clamp is accessible with an impact wrench. Within 30 s, tighten all clamps with an impact or manual wrench and record the surface temperature of the workpiece in 3 locations along the length of the forming region with a reed-type thermocouple probe.</li>
	<li>Repeat step 3.4 until the workpiece is at an appropriate forming temperature; at a minimum, 350 &#176;C for A356. Perform a final tightening of the clamps with an impact wrench set to 200 Nm.</li>
	<li>Move the roller axially and radially (approx. 2-5 mm from workpiece surface) into position for forming, and perform one last clamp tightening (i.e. step 3.4).</li>
	<li>With the heating system on, increase the rotation rate of the lathe to the intended forming speed, engage the roller to a pre-set depth into the workpiece, and activate the screw-cutting feed to move the roller axially along the length of the workpiece. 
	NOTE: For the present geometry, reasonable results were attained at 281 rpm with an axial movement of 0.21 mm/revolution.</li>
	<li>Repeat Step 3.7 as required to increase levels of deformation. After each forming pass, ensure that the temperature does not drop below the optimal forming temperature by stopping the mandrel and using the same reed-type thermocouple probe as employed in step 3.4. If the optimal forming temperature has dropped, repeat steps 3.4 and 3.5 to reheat. 
	NOTE: Reheating can be employed, however at the expense of potentially reaching the extent of the clamp system&#39;s ability to restrain the workpiece.</li>
</ol>
4. Post Forming Operations
<ol>
	<li>Once the desired level of deformation has been obtained, stop the heating system, and undo all clamps, and disengage the tailstock to obtain clearance for workpiece removal.</li>
	<li>Gently tap the workpiece with a piece of brass to separate from the mandrel. If this proves to be ineffective, re-engage the heating system and rotate the mandrel at 20 rpm gently tapping until the blank separates.</li>
	<li>Using an appropriate manipulation tool such as tongs or heavily insulated gloves, either quench the workpiece in water at 60 &#176;C to prevent further ageing, or leave to air cool to minimize residual stress/distortion.</li>
</ol>

<ol>
	<li>Wong, C., Dean, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+review+of+spinning,+shear+forming+and+flow+forming+processes.">A review of spinning, shear forming and flow forming processes.</a> Int. J Mach Tool Manu. 43 (14), 1419-1435 (2003).</li><li>Music, O., Allwood, J. M., Kawai, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+review+of+the+mechanics+of+metal+spinning.">A review of the mechanics of metal spinning.</a> J Mater Process Tech. 210 (1), 3-23 (2010).</li><li>Razani, N. A., Jalali Aghchai, A., Mollaei Dariani, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Flow-forming+optimization+based+on+hardness+of+flow-formed+AISI321+tube+using+response+surface+method.">Flow-forming optimization based on hardness of flow-formed AISI321 tube using response surface method.</a> Int J Adv Manuf Tech. 70 (5), 1463-1471 (2014).</li><li>Abedini, A., Rash Ahmadi, S., Doniavi, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Roughness+optimization+of+flow-formed+tubes+using+the+Taguchi+method.">Roughness optimization of flow-formed tubes using the Taguchi method.</a> Int J Adv Manuf Tech. 72 (5), 1009-1019 (2014).</li><li>Davidson, M. J., Balasubramanian, K., Tagore, G. R. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+investigation+on+flow-forming+of+AA6061+alloy-A+Taguchi+approach.">Experimental investigation on flow-forming of AA6061 alloy-A Taguchi approach.</a> J Mater Process Tech. 200 (1-3), 283-287 (2008).</li><li>Cheng, Y. C., Lin, C. K., Tan, A. H., Lin, J. C., Lee, S. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+Spinning+Deformation+Processing+on+the+Wear+and+Corrosion+Properties+of+Al-7Si-0.3Mg+Alloys.">Effect of Spinning Deformation Processing on the Wear and Corrosion Properties of Al-7Si-0.3Mg Alloys.</a> Mater Manuf Process. 25 (7), 689-695 (2010).</li><li>Mori, K., Ishiguro, M., Isomura, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hot+shear+spinning+of+cast+aluminium+alloy+parts.">Hot shear spinning of cast aluminium alloy parts.</a> J Mater Process Tech. 209 (7), 3621-3627 (2009).</li><li>Roy, M. J., Maijer, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Response+of+A356+to+warm+rotary+forming+and+subsequent+T6+heat+treatment.">Response of A356 to warm rotary forming and subsequent T6 heat treatment.</a> Mat Sci Eng A-Struct. 611, 223-233 (2014).</li><li>Roy, M. J., Maijer, D. M., Dancoine, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Constitutive+behavior+of+as-cast+A356.">Constitutive behavior of as-cast A356.</a> Mat Sci Eng A-Struct. 548, 195-205 (2012).</li><li>Molladavoudi, H. R., Djavanroodi, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+study+of+thickness+reduction+effects+on+mechanical+properties+and+spinning+accuracy+of+aluminum+7075-O,+during+flow+forming.">Experimental study of thickness reduction effects on mechanical properties and spinning accuracy of aluminum 7075-O, during flow forming.</a> Int J Adv Manuf Tech. 52 (9), 949-957 (2011).</li><li>Smolenicki, D., Boos, J., Kuster, F., Roelofs, H., Wyen, C. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In-process+measurement+of+friction+coefficient+in+orthogonal+cutting.">In-process measurement of friction coefficient in orthogonal cutting.</a> CIRP Ann-Manuf Techn. 63 (1), 97-100 (2014).</li><li>Xu, W., Zhao, X., Ma, H., Shan, D., Lin, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influence+of+roller+distribution+modes+on+spinning+force+during+tube+spinning.">Influence of roller distribution modes on spinning force during tube spinning.</a> Int J Mech Sci. 113, 10-25 (2016).</li><li>Roy, M. J., Maijer, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+and+modelling+of+a+rotary+forming+process+for+cast+aluminium+alloy+A356.">Analysis and modelling of a rotary forming process for cast aluminium alloy A356.</a> J Mater Process Tech. 226, 188-204 (2015).</li><li>Lu, P., Zhang, Y. K., Ma, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Finite+element+analysis+on+multi-step+rolling+process+and+controlling+quality+defect+for+steel+wheel+rim.">Finite element analysis on multi-step rolling process and controlling quality defect for steel wheel rim.</a> Adv Mech Eng. 7 (7), 1-11 (2015).</li></ol>

The authors have nothing to disclose.

The representative results shown above highlight that the protocol and equipment employed is capable of forming cast aluminum at elevated temperatures, and has provided a platform to determine a processing window for flow forming of wheels. The technique demonstrated can be used to explore aspects of forming envelopes, including how both formed and unformed material responds to heat treatment8. However, there is room for improvement with the current processing protocol with this apparatus.
Regarding further instrumentation, which would accelerate process model development, the inclusion of machine-tool dynamometer and tribometers11,12 to measure forming loads and friction factors on the roller would provide important information about the process conditions. This is a widely employed instrumentation technique for orthogonal machining studies, and could be readily implemented on the current machine. This additional instrumentation would provide useful data to accurately validate of modelling efforts13,14 and support the increasing industrial interest in this process. In order to effectively capture the evolution of temperature of the blank during processing, a non-contact measurement technique is desirable. However, common infrared-based techniques are hampered by aluminum&#39;s low emissivity and how the surface changes during processing. This is the principal reason why an instrumented, commissioning blank was employed to capture the typical thermal response achieved with the protocol described, and served to populate a baseline heat transfer analysis to relate mandrel surface temperature to the workpiece.
As it is largely a manual forming process for a material which is sensitive to time at temperature, some inconsistencies between run to run are to be expected. Aluminum alloys have microstructures that are highly sensitive to temperatures above 100&#176;C due to ageing mechanisms. Therefore, the most critical steps within the protocol are 1.2 and 3.3-3.7, where the blank is at elevated temperatures. Tightening and re-seating the clamps must be conducted as quickly as possible to maintain repeatability between forming operations.
The in situ workpiece heating employed during the pre-heating step is quite inefficient and could be improved via radiative heating. The overall processing speeds in terms of mandrel and tool movements that can be attained are somewhat limited by the capabilities of the lathe employed. Higher forming speeds require a more rigid frame with a higher load capacity, particularly if the forming of a stronger material were to be attempted. Workpiece clamping and release could be improved with the addition of hydraulic or pneumatic actuation. As heat transfer from the blank to the mandrel is largely a function of the pressure imposed by the workpiece onto the mandrel, this addition could also improve a model-based approach to ascertain the workpiece temperature during forming with the existing system.
The apparatus and procedure described has shown that forming loads for this material under these conditions approaches those for standard turning operations, and remains a very cost effective process by which to perform manufacturing trials. Research into different manufacturing routes and formability can be performed away from commercial forming equipment, which is exceedingly expensive to operate. With the apparatus and protocol described, processing parameters can be investigated prior to constructing larger scale, higher throughput equipment, and to the authors&#39; knowledge, is a unique approach.
As the protocol developed has only been applied to one specific variant of cast aluminum alloy, there is a multitude of other aluminum foundry alloys which could be investigated for a variety of applications beyond automotive wheels. As these alloys have approximately similar processing windows from a temperature perspective, the protocol developed can be readily adapted.

One of the more challenging metal forming operations currently being practiced in the aerospace and transportation sectors is metal spinning, including derivatives such as shear forming and flow forming1,2. In this process, an axisymmetric workpiece is placed on a mandrel representing the final desired shape, and spun into contact with one or more impinging rollers. The workpiece being compressed between the roller and mandrel then plastically deforms, with a diverse response including combined bending, thinning and axial elongation. In a material which has limited ductility or is otherwise difficult to form, this is sometimes carried out at elevated temperature to decrease flow stress and increase ductility.
From a processing standpoint, there are a wide range of parameters which can dictate the shape and properties of the manufactured component. Numerous studies have focused on statistical techniques for optimizing various parameters3,4,5. Variables include tooling geometry, such as the shape of the tool and mandrel; forming speeds including both mandrel rotation rate and tooling feed rates; as well as material properties. When elevated temperatures are required, practitioners need to assess the minimum temperature required while still retaining a sound product.
Cast aluminum alloys are employed in a wide variety of automotive and aerospace applications, with alloy A356 used in automotive wheels. However, this alloy is not suitable for forming at room temperature6,7 owing to its limited ductility and must be formed at elevated temperatures. This introduces a host of processing complexity, principally in controlling temperature. As this material&#39;s properties change significantly with temperature8, it is particularly important to perform instrumented trials in which thermal conditions can be kept to within a reasonable processing window and be monitored. Detailed data on the thermomechanical behavior of as-cast A356 ranging from ambient temperature to 500 &#176;C over a wide range of strain rates can be reviewed elsewhere.9
In order to support development and optimization of flow forming operations for wheel manufacturing, custom forming equipment has been developed at the Department of Materials Engineering at the University of British Columbia (Figure 1). This apparatus has been built primarily from a manual, belt-driven capstan lathe with a total output of 22 kW, and a propane torch heating system with a peak output of 82 kW (Figure 2). A mandrel with embedded thermocouples along with a rigid roller assembly (Figure 3) has been installed, which is capable of forming workpieces up to 330 mm in diameter. The mandrel has a manually activated clamping system which is able to account for large changes in workpiece diameter occurring during processing (Figure 4). A battery operated Data Acquisition (DAQ) system containing a miniature wireless computer capable of monitoring the temperature of the mandrel during forming and the blank for characterizing heating has been installed on the quill of the lathe. While other flow forming processes have been synthesized using adapted lathes4,10, the present apparatus is the first to embody in situ heating and thermal data acquisition.
A processing protocol for industrially-scaled forming operations has been developed to provide indicative processing conditions. Described subsequently, this protocol consists of tooling and workpiece preparation, forming practice, concluding with end of forming trial operations.
<img alt="Figure 1" src="/files/ftp_upload/55061/55061fig1.jpg" /> 
Figure 1: Experimental apparatus overview. Principle components which have been added to a modified capstan lathe for forming at elevated temperatures. Photograph of equipment (top) and main working directions and components labelled on a computer-aided design depiction (bottom). <a href="https://cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55061/55061fig1large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 2" src="/files/ftp_upload/55061/55061fig2.jpg" /> 
Figure 2: Heating system detail. A propane heating system with four discrete burners (top and bottom right) actuated from a central manifold containing a gas control solenoid (top and bottom left). Gas pressure and a discrete flow rate to each of the burners is possible, along with placement along the blank to conform to different geometries. <a href="https://cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55061/55061fig2large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 3" src="/files/ftp_upload/55061/55061fig3.jpg" /> 
Figure 3: Roller stand assembly detail. The original tool holder on for the lathe has been adapted to hold a roller at arbitrary angles relative to the turning axis of the mandrel via a jam nut assembly. <a href="https://cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55061/55061fig3large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 4" src="/files/ftp_upload/55061/55061fig4.jpg" /> 
Figure 4: Instrumented mandrel and clamp system overview. The rotary tooling has been designed to bolt directly to the lathe spindle, which is in turn supported by a live center on the tailstock (top and bottom left). Clamp assembly/operation is also depicted (top and bottom right). <a href="https://cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55061/55061fig4large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

<table border="0" cellpadding="0" cellspacing="0" width="914">
	<tbody>
		<tr height="20">
			<td height="20" style="height:20px;width:184px;">Reagent/Material</td>
			<td style="width:212px;"></td>
			<td style="width:224px;"></td>
			<td style="width:295px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">High temperature grease</td>
			<td>Dow Corning</td>
			<td>Molycote M-77</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">High temperature lubricant</td>
			<td>Superior Graphite</td>
			<td>sureCOAT</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">High temperature die coat</td>
			<td>Vesuvius/Foseco</td>
			<td>DYCOTE 32</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:184px;">Name</td>
			<td style="width:212px;">Company</td>
			<td style="width:224px;">Catalog Number</td>
			<td style="width:295px;">Comments</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Equipment</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Live center</td>
			<td>Riten Industries</td>
			<td align="right">17124</td>
			<td>Bell-head, spring loaded</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Live center adapter</td>
			<td>Riten Industries</td>
			<td align="right">431</td>
			<td>Adapter for lathe</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Impact wrench</td>
			<td>Chicago Pneumatic</td>
			<td>CP7749-2</td>
			<td>1/2&#34; drive, 0-545 ft-lb</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Torque wrench</td>
			<td>Westward Tools</td>
			<td>6PAG0</td>
			<td>1/2&#34; drive, 0-250 ft-lb</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Air-powered paint sprayer</td>
			<td>Cambell Hausfeld</td>
			<td>DH4200</td>
			<td>For die coat</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Air-powered paint sprayer</td>
			<td>Cambell Hausfeld</td>
			<td>DH5500</td>
			<td>For graphite-based lubricant, high volume low pressure (HVLP) type</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Data acquisition unit</td>
			<td>Measurement Computing</td>
			<td>USB-2416</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Reed thermocouple</td>
			<td>Omega Engineering</td>
			<td align="right">88108</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Propane tank</td>
			<td>Generic</td>
			<td></td>
			<td>20/40 lb, POL fitted</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Solenoid valve</td>
			<td>Aztec Heating</td>
			<td>SV-S121</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Gas regulator</td>
			<td>Aztec Heating</td>
			<td>67CH-743</td>
			<td>0-30 psi</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Burner tips</td>
			<td>Exact</td>
			<td align="right">3119</td>
			<td>Qty: 4</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Roller bearings</td>
			<td>SKF</td>
			<td>32005 X/Q</td>
			<td>Qty: 2</td>
		</tr>
	</tbody>
</table>

experimental procedure for warm spinning of cast aluminum components

High performance, cast aluminum automotive wheels are increasingly being incrementally formed via flow forming/metal spinning at elevated temperatures to improve material properties. With a wide array of processing parameters which can affect both the shape attained and resulting material properties, this type of processing is notoriously difficult to commission. A simplified, light-duty version of the process has been designed and implemented for full-size automotive wheels. The apparatus is intended to assist in understanding the deformation mechanisms and the material response to this type of processing. An experimental protocol has been developed to prepare for, and subsequently perform forming trials and is described for as-cast A356 wheel blanks. The thermal profile attained, along with instrumentation details are provided. Similitude with full-scale forming operations which impart significantly more deformation at faster rates is discussed.

As-cast aluminum A356 workpieces were formed according to the method described in this paper. The workpieces were obtained from as-cast wheels from a North American wheel manufacturer employing the low-pressure die casting process. One workpiece instrumented with thermocouples was not formed, but underwent the pre-heating cycle (Protocol Section 3, steps 3.3-3.5) to capture the distribution of temperature across the surface of the blank during this aspect of the process. This response is shown in Figure 5. A further 3 samples were deformed to various levels, including one which received two forming passes for a high level of deformation. The first two samples and the first pass performed on the latter sample served to straighten the workpiece with little demonstrable change in wall thickness. The latter sample peak wall thickness reduction was approximately 10%, the majority of which was achieved in the second pass. Cross-sections and microstructure of the as-cast blank and those obtained in multi-pass sample are shown in Figure 6. Here, the as-cast microstructure is shown to significantly be refined by the process with dendritic features barely discernable. The interdendritic eutectic is broken up by the deformation imposed, creating a much more homogenous microstructure than in the as-cast state. This improves the overall ductility as well as fatigue and fracture properties of the component. The authors have previously described more details of workpiece geometry, specific cross-sectional changes in wall thickness, defects observed, and dimensional variation in microstructure on the full set of samples8,13.
<img alt="Figure 5" src="/files/ftp_upload/55061/55061fig5.jpg" /> 
Figure 5: Typical temperature profile of mandrel and blank. A representative transient thermal response of the blank and mandrel obtained with the heating system. Vertical dashed lines indicate where clamps were tightened during the preheating steps, and the black arrow depicts forming. The last vertical line shows where the heating system was turned off whilst the system cooled.
<img alt="Figure 6" src="/files/ftp_upload/55061/55061fig6.jpg" /> 
Figure 6: As-cast and formed result. The as-received, as-cast blank surface and geometry having a minimum inner diameter of 330 mm (top) was deformed in two passes to provide the result shown (middle). The as-cast dendritic microstructure (bottom left) is visibly modified by the forming operation and a subsequent T6 heat treatment (bottom right) as observed with optical microscopy8,13. <a href="https://cloudflare-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55061/55061fig6large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

Watch this Scientific Journal Video about Experimental Procedure for Warm Spinning of Cast Aluminum Components at JoVE.com

Experimental Procedure for Warm Spinning of Cast Aluminum Components

An experimental protocol for instrumented warm rotary forming of cast aluminum alloys employing a bespoke industrially scaled apparatus is presented. Experimental considerations including thermal and mechanical effects are discussed, as well as similitude with full-scale processing of automotive wheels.

High performance, cast aluminum automotive wheels are increasingly being incrementally formed via flow forming/metal spinning at elevated temperatures to ...

experimental-procedure-for-warm-spinning-of-cast-aluminum-components

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Rotation and Rigid Bodies

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9.4K Views.  University of Manchester. An experimental protocol for instrumented warm rotary forming of cast aluminum alloys employing a bespoke industrially scaled apparatus is presented. Experimental considerations including thermal and mechanical effects are discussed, as well as similitude with full-scale processing of automotive wheels.

Video: Experimental Procedure for Warm Spinning of Cast Aluminum Components

Gradient Echo Quantum Memory in Warm Atomic Vapor

Gradient echo memory (GEM) is a protocol for storing optical quantum states of light in atomic ensembles. The primary motivation for such a technology is that quantum key distribution (QKD), which uses Heisenberg uncertainty to guarantee security of cryptographic keys, is limited in transmission distance. The development of a quantum repeater is a possible path to extend QKD range, but a repeater will need a quantum memory. In our experiments we use a gas of rubidium 87 vapor that is contained in a warm gas cell. This makes the scheme particularly simple. It is also a highly versatile scheme that enables in-memory refinement of the stored state, such as frequency shifting and bandwidth manipulation. The basis of the GEM protocol is to absorb the light into an ensemble of atoms that has been prepared in a magnetic field gradient. The reversal of this gradient leads to rephasing of the atomic polarization and thus recall of the stored optical state. We will outline how we prepare the atoms and this gradient and also describe some of the pitfalls that need to be avoided, in particular four-wave mixing, which can give rise to optical gain.

The gradient echo memory is a protocol for storing optical quantum states of light in atomic ensembles. Quantum memory is a key element of a quantum repeater, which can extend the range of quantum key distribution. We outline the operation of the scheme when implemented in a 3-level atomic ensemble.

Gradient  echo memory (GEM) is a protocol for storing optical quantum states of light in  atomic ensembles. The primary motivation for such a technology ...

Casting Protocols for the Production of Open Cell Aluminum Foams by the Replication Technique and the Effect on Porosity

Metal foams are interesting materials from both a fundamental understanding and practical applications point of view. Uses have been proposed, and in many cases validated experimentally, for light weight or impact energy absorbing structures, as high surface area heat exchangers or electrodes, as implants to the body, and many more. Although great progress has been made in understanding their structure-properties relationships, the large number of different processing techniques, each producing material with different characteristics and structure, means that understanding of the individual effects of all aspects of structure is not complete. The replication process, where molten metal is infiltrated between grains of a removable preform material, allows a markedly high degree of control and has been used to good effect to elucidate some of these relationships. Nevertheless, the process has many steps that are dependent on individual &#8220;know-how&#8221;, and this paper aims to provide a detailed description of all stages of one embodiment of this processing method, using materials and equipment that would be relatively easy to set up in a research environment. The goal of this protocol and its variants is to produce metal foams in an effective and simple way, giving the possibility to tailor the outcome of the samples by modifying certain steps within the process. By following this, open cell aluminum foams with pore sizes of 1&#8211;2.36 mm diameter and 61% to 77% porosity can be obtained.

Replication is one of the processing techniques used for the production of porous metal sponges. In this paper one implementation of the method for the production of open celled porous aluminum is shown in detail.

Metal foams are interesting materials from both a fundamental understanding and practical applications point of view. Uses have been proposed, and in many ...

Advanced Experimental Methods for Low-temperature Magnetotransport Measurement of Novel Materials

Novel electronic materials are often produced for the first time by synthesis processes that yield bulk crystals (in contrast to single crystal thin film synthesis) for the purpose of exploratory materials research. Certain materials pose a challenge wherein the traditional bulk Hall bar device fabrication method is insufficient to produce a measureable device for sample transport measurement, principally because the single crystal size is too small to attach wire leads to the sample in a Hall bar configuration. This can be, for example, because the first batch of a new material synthesized yields very small single crystals or because flakes of samples of one to very few monolayers are desired. In order to enable rapid characterization of materials that may be carried out in parallel with improvements to their growth methodology, a method of device fabrication for very small samples has been devised to permit the characterization of novel materials as soon as a preliminary batch has been produced. A slight variation of this methodology is applicable to producing devices using exfoliated samples of two-dimensional materials such as graphene, hexagonal boron nitride (hBN), and transition metal dichalcogenides (TMDs), as well as multilayer heterostructures of such materials. Here we present detailed protocols for the experimental device fabrication of fragments and flakes of novel materials with micron-sized dimensions onto substrate and subsequent measurement in a commercial superconducting magnet, dry helium close-cycle cryostat magnetotransport system at temperatures down to 0.300 K and magnetic fields up to 12 T.

We describe the methodology of mechanical exfoliation and deposition of flakes of novel materials with micron-sized dimensions onto substrate, fabrication of experimental device structures for transport experimentation, and the magnetotransport measurement in a dry helium close-cycle cryostat at temperatures down to 0.300 K and magnetic fields up to 12 T.

Novel electronic materials are often produced for the first time by synthesis processes that yield bulk crystals (in contrast to single crystal thin film ...

SSVEP-based Experimental Procedure for Brain-Robot Interaction with Humanoid Robots

Brain-Robot Interaction (BRI), which provides an innovative communication pathway between human and a robotic device via brain signals, is prospective in helping the disabled in their daily lives. The overall goal of our method is to establish an SSVEP-based experimental procedure by integrating multiple software programs, such as OpenViBE, Choregraph, and Central software as well as user developed programs written in C++ and MATLAB, to enable the study of brain-robot interaction with humanoid robots.
This is achieved by first placing EEG electrodes on a human subject to measure the brain responses through an EEG data acquisition system. A user interface is used to elicit SSVEP responses and to display video feedback in the closed-loop control experiments. The second step is to record the EEG signals of first-time subjects, to analyze their SSVEP features offline, and to train the classifier for each subject. Next, the Online Signal Processor and the Robot Controller are configured for the online control of a humanoid robot. As the final step, the subject completes three specific closed-loop control experiments within different environments to evaluate the brain-robot interaction performance.
The advantage of this approach is its reliability and flexibility because it is developed by integrating multiple software programs. The results show that using this approach, the subject is capable of interacting with the humanoid robot via brain signals. This allows the mind-controlled humanoid robot to perform typical tasks that are popular in robotic research and are helpful in assisting the disabled.

The overall goal of this method is to establish an SSVEP-based experimental procedure by integrating multiple software programs to enable the study of brain-robot interaction with humanoid robots, which is prospective in assisting the sick and elderly as well as performing unsanitary or dangerous jobs.

Brain-Robot Interaction (BRI), which provides an innovative communication pathway between human and a robotic device via brain signals, is prospective in ...

How to Build a Vacuum Spring-transport Package for Spinning Rotor Gauges

The spinning rotor gauge (SRG) is a high-vacuum gauge often used as a secondary or transfer standard for vacuum pressures in the range of 1.0 x 10-4 Pa to 1.0 Pa. In this application, the SRGs are frequently transported to laboratories for calibration. Events can occur during transportation that change the rotor surface conditions, thus changing the calibration factor. To assure calibration stability, a spring-transport mechanism is often used to immobilize the rotor and keep it under vacuum during transport. It is also important to transport the spring-transport mechanism using packaging designed to minimize the risk of damage during shipping. In this manuscript, a detailed description is given on how to build a robust spring-transport mechanism and shipping container. Together these form a spring-transport package. The spring-transport package design was tested using drop-tests and the performance was found to be excellent. The present spring-transport mechanism design keeps the rotor immobilized when experiencing shocks of several hundred g (g = 9.8 m/sec2 and is the acceleration due to gravity), while the shipping container assures that the mechanism will not experience shocks greater than about 100 g during common shipping mishaps (as defined by industry standards).

Here we describe how to build a robust spring-transport mechanism for a spinning rotor gauge. This device securely immobilizes the rotor and keeps it under vacuum during transportation. We also describe packaging that minimizes the risk of damage during transport. Tests show our design works for typical shocks during transport.

The spinning rotor gauge (SRG) is a high-vacuum gauge often used as a secondary or transfer standard for vacuum pressures in the range of 1.0 x 10-4 Pa to ...

Reaction Kinetics and Combustion Dynamics of I4O9 and Aluminum Mixtures

Tetraiodine nonoxide (I4O9) has been synthesized using a dry approach that combines elemental oxygen and iodine without the introduction of hydrated species. The synthesis approach inhibits the topochemical effect promoting rapid hydration when exposed to the relative humidity of ambient air. This stable, amorphous, nano-particle material was analyzed using differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) and showed an exothermic energy release at low temperature (i.e., 180 &#176;C) for the transformation of I4O9 into I2O5. This additional exothermic energy release contributes to an increase in overall reactivity of I4O9 when dry mixed with nano-aluminum (Al) powder, resulting in a minimum of 150% increase in flame speed compared to Al + I2O5. This study shows that as an oxidizer, I4O9 has more reactive potential than other forms of iodine(V) oxide when combined with Al, especially if I4O9 can be passivated to inhibit absorption of water from its surrounding environment.

Reaction Kinetics and Combustion Dynamics of I4O9 and Aluminum Mixtures

A protocol for measuring flame speeds of a reactive mixture composed of tetraiodine nonoxide (I4O9) and aluminum (Al) is presented. A method for resolving reaction kinetics using differential scanning calorimetry (DSC) is also presented. It was found that I4O9 is 150% more reactive than other iodine(V) oxides.

Tetraiodine nonoxide (I4O9) has been synthesized using a dry approach that combines elemental oxygen and iodine without the introduction of hydrated ...

Experimental Methods for Trapping Ions Using Microfabricated Surface Ion Traps

Ions trapped in a quadrupole Paul trap have been considered one of the strong physical candidates to implement quantum information processing. This is due to their long coherence time and their capability to manipulate and detect individual quantum bits (qubits). In more recent years, microfabricated surface ion traps have received more attention for large-scale integrated qubit platforms. This paper presents a microfabrication methodology for ion traps using micro-electro-mechanical system (MEMS) technology, including the fabrication method for a 14 &#181;m-thick dielectric layer and metal overhang structures atop the dielectric layer. In addition, an experimental procedure for trapping ytterbium (Yb) ions of isotope 174 (174Yb+) using 369.5 nm, 399 nm, and 935 nm diode lasers is described. These methodologies and procedures involve many scientific and engineering disciplines, and this paper first presents the detailed experimental procedures. The methods discussed in this paper can easily be extended to the trapping of Yb ions of isotope 171 (171Yb+) and to the manipulation of qubits.

This paper presents a microfabrication methodology for surface ion traps, as well as a detailed experimental procedure for trapping ytterbium ions in a room-temperature environment.

Ions trapped in a quadrupole Paul trap have been considered one of the strong physical candidates to implement quantum information processing. This is due ...

An Available Technique for Preparation of New Cast MnCuNiFeZnAl Alloy with Superior Damping Capacity and High Service Temperature

Manganese (Mn)-copper (Cu)-based alloys have been found to have&#160;damping capacity and can be used to reduce harmful vibrations and noise effectively. M2052 (Mn-20Cu-5Ni-2Fe, at%) is an important branch of Mn-Cu-based alloys, which possesses both excellent damping capacity and processability. In recent decades, lots of studies have been carried out on the performance optimization of M2052, improving the damping capacity, mechanical properties, corrosion resistance, and service temperature, etc. The major methods of performance optimization are alloying, heat treatment, pretreatment, and different ways of molding etc., among which alloying, as well as adopting a reasonable heat treatment, is the simplest and most effective method to obtain perfect and comprehensive performance. To obtain the M2052 alloy with excellent performance for casting molding, we propose to add Zn and Al to the MnCuNiFe alloy matrix and use a variety of heat treatment methods for a comparison in the microstructure, damping capacity, and service temperature. Thus, a new type of cast-aged Mn-22.68Cu-1.89Ni-1.99Fe-1.70Zn-6.16Al (at.%) alloy with&#160;superior damping capacity and high service temperature is obtained by an optimized heat treatment method. Compared with the forging technique, cast molding is simpler and more efficient, and the damping capacity of this as-cast alloy is excellent. Therefore, there is a suitable reason to think that it is a good choice for engineering applications.

Here we present a protocol to obtain a novel Mn-Cu-based alloy with excellent comprehensive performances by a high-quality smelting technology and reasonable heat treatment methods.

Manganese (Mn)-copper (Cu)-based alloys have been found to have&#160;damping capacity and can be used to reduce harmful vibrations and noise effectively. ...

Enhanced Electron Injection and Exciton Confinement for Pure Blue Quantum-Dot Light-Emitting Diodes by Introducing Partially Oxidized Aluminum Cathode

Stable and efficient red (R), green (G), and blue (B) light sources based on solution-processed quantum dots (QDs) play important roles in next-generation displays and solid-state lighting technologies. The brightness and efficiency of blue QDs-based light-emitting diodes (LEDs) remain inferior to their red and green counterparts, due to the inherently unfavorable energy levels of different colors of light. To solve these problems, a device structure should be designed to balance the injection holes and electrons into the emissive QD layer. Herein, through a simple autoxidation strategy, pure blue QD-LEDs which are highly bright and efficient are demonstrated, with a structure of ITO/PEDOT:PSS/Poly-TPD/QDs/Al:Al2O3. The autoxidized Al:Al2O3 cathode can effectively balance the injected charges and enhance radiative recombination without introducing an additional electron transport layer (ETL). As a result, high color-saturated blue QD-LEDs are achieved with a maximum luminance over 13,000 cd m-2, and a maximum current efficiency of 1.15 cd A-1. The easily controlled autoxidation procedure paves the way for achieving high-performance blue QD-LEDs.

A protocol is presented for fabricating high-performance, pure blue ZnCdS/ZnS-based quantum dots light-emitting diodes by employing an autoxidized aluminum cathode.

Stable and efficient red (R), green (G), and blue (B) light sources based on solution-processed quantum dots (QDs) play important roles in next-generation ...

Experimental Procedure for Laboratory Studies of In Situ Burning : Flammability and Burning Efficiency of Crude Oil

A new method for the simultaneous study of the flammability and burning efficiency of fresh and weathered crude oil through two experimental laboratory setups is presented. The experiments are easily repeatable compared to operational scale experiments (pool diameter &#8805;2 m), while still featuring quite realistic in situ burning conditions of crude oil on water. Experimental conditions include a flowing water sub-layer that cools the oil slick and an external heat flux (up to 50 kW/m2) that simulates the higher heat feedback to the fuel surface in operational scale crude oil pool fires. These conditions enable a controlled laboratory study of the burning efficiency of crude oil pool fires that are equivalent to operational scale experiments. The method also provides quantitative data on the requirements for igniting crude oils in terms of the critical heat flux, ignition delay time as a function of the incident heat flux, the surface temperature upon ignition, and the thermal inertia. This type of data can be used to determine the required strength and duration of an ignition source to ignite a certain type of fresh or weathered crude oil. The main limitation of the method is that the cooling effect of the flowing water sub-layer on the burning crude oil as a function of the external heat flux has not been fully quantified. Experimental results clearly showed that the flowing water sub-layer does improve how representative this setup is of in situ burning conditions, but to what extent this representation is accurate is currently uncertain. The method nevertheless features the most realistic in situ burning laboratory conditions currently available for simultaneously studying the flammability and burning efficiency of crude oil on water.

Experimental Procedure for Laboratory Studies of In Situ Burning : Flammability and Burning Efficiency of Crude Oil

Here, we present a protocol to simultaneously study the flammability and burning efficiency of fresh and weathered crude oil under conditions that simulate in situ burning operations on the sea.

A new method for the simultaneous study of the flammability and burning efficiency of fresh and weathered crude oil through two experimental laboratory ...