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The Effect of HIP Processing on the Properties of A356 T6 Cast Aluminum Steering Knuckles
Technical Paper
2004-01-1027
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
Hot Isostatic Pressing (HIP) has been routinely used to densify castings for aerospace and medical applications for over 30 years. While HIP is widely known to improve the toughness and fatigue life of castings through the healing of internal porosity, it has been perceived as too expensive for most cast aluminum alloys for automotive applications. Recent developments suggest that the cost effectiveness of certain special HIP processes should be revisited due to reductions in process cost and improvements in throughput. This paper will evaluate the Densal® II process applied to a front aluminum steering knuckle. Two casting processes representing differing levels of relative cost and quality were evaluated. The first was Alcoa's VRC/PRC process, a metal mold process with bottom fill, evacuation before fill and pressurization after fill. This is considered to be a premium quality, but higher cost casting process that is already qualified for this application. The second was a high-rate, bottom fill, Disamatic sand casting process operated by Robinson Foundry. This process is considered a lower cost process. All parts were evaluated in the as cast + T6 condition and after Densal® II + T6 processing to evaluate microstructure and density. The tensile properties and fatigue curves were established and compared. Fracture analysis using Scanning Electron Microscopy was performed to help understand the fatigue results. The total costs are estimated for both casting techniques and the suitability of the resultant products for critical automotive structures is discussed.
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Citation
Hebeisen, J. and Cox, B., "The Effect of HIP Processing on the Properties of A356 T6 Cast Aluminum Steering Knuckles," SAE Technical Paper 2004-01-1027, 2004, https://doi.org/10.4271/2004-01-1027.Also In
Advances in Lightweight Automotive Castings and Wrought Aluminum Alloys
Number: SP-1838; Published: 2004-03-08
Number: SP-1838; Published: 2004-03-08
References
- Dayton, R.W. Saller, H.A. “The Fabrication of Zirconium Alloy SIR Fuel Elements” Battelle Memorial Institute Columbus, Ohio August 13 1954
- Kerr, D.L. Lemon, R.C. Stonebrook, E.E. February 20 1970
- Widmer, R. “HIP'ing Makes Inroads in Casting Densification” Metal Progress - Foundry Technology ASM August 1982
- Hanes, H.D. McFadden, J.M. “HIP'ing of Castings: An Update” Metal Progress ASM April 1983
- Boileau, J.M. Allison, J.E. “The Effect of Porosity Size on the Fatigue Properties in a Cast 319 Aluminum Alloy” SAE Paper No. 2001-01-0818 SAE Warrendale, PA 2001
- Boileau, J.M. Zindel, J.W. Allison, J.E. “The Effect of Solidification Time on the Mechanical Properties in a Cast A356-T6 Aluminum Alloy” SAE Report No. 970019 SAE Warrendale, PA 1997
- Boileau, J.M. “The Effect of Solidification Time on the Mechanical Properties of a Cast 319 Aluminum Alloy” Wayne State University Detroit, MI December 1 1999
- “Casting Densification Process” Alcoa Technology Marketing Division Alcoa Pittsburgh, PA
- Hebeisen, J.C. “HIP Casting Densification” ASME Pressure Vessel and Piping Conference Proceedings Boston, MA August 1999
- Mashl, S.J. Hebeisen, J.C. Apelian, D. Wang, Q. “Hot Isostatic Pressing of A356 and 380/383 Aluminum Alloys: An Evaluation of Porosity, Fatigue Properties and Processing Costs” SAE Report 2000-01-0062 SAE Warrendale, PA 2000
- Diem, M.M. Mashl, S.J. Sisson, R.D. “A Combination HIP + Heat Treat Process” Heat Treat Progress June/July 2003 52 55
- Wang, Q.G. Apelian, D. Lados, D.A. “Fatigue Behavior of A356-T6 Aluminum Cast Alloys. Part 1. Effect of Casting Defects” Journal of Light Metals 1 2001 73 84
- Spada, A.T. “Vertically-Speaking, Robinson Debuts Aluminum Green Sand Casting” Modern Casting Sept 2001
- Hebeisen, J.C. Cox, B.M. Rampulla, B. “Improving the Quality of Commercial Aluminum Castings for Airframe and Automotive Applications using the Densal® Process” International Symposium on Aluminum Applications: Thrusts and Challenges, Present and Future, ASM Materials Solutions Conf. October 13-16 2003 Pittsburgh, PA