Rheocasting an Engine Mounting Bracket in Commercial 7075
Wrought aluminium alloys are prone to hot tearing when cast into near-net shapes. This problem can be overcome by the novel casting technique of rheo-processing combined with high pressure die casting. An industrial engine mounting bracket is produced by rheo-process commercial 7075 with the patented CSIR-RCS and subsequent high pressure die casting. Section thickness changes and constraining geometry make this a difficult component to rheocast. X-ray radiography is used to evaluate hot tearing over the component and is correlated to piston injection shot profile velocities. Gross hot tearing is significantly reduced by a higher injection velocity but turbulent flow entraps air. Faster injection allows more time for flow before final solidification.
Hajo Dieringa, Norbert Hort and Karl Ulrich Kainer
U. A. Curle "Rheocasting an Engine Mounting Bracket in Commercial 7075", Materials Science Forum, Vol. 690, pp. 133-136, 2011