093/1 The Effects of HIP on Bifilms in Aluminum Castings J T Staley *, M Tiryakioğlu **, J Campbell *** * Bodycote Materials Testing, Chicago Laboratory, USA, ** Robert Morris University, USA, *** The University of Birmingham, UK Abstract Many aluminum castings contain bifilms, which are cracks that lower the mechanical properties and reliability of castings. The current commercial hot isostatic pressing (HIP) process has proven successful in closing porosity but its success in healing bifilms is questionable. This research investigates the effects of different HIP conditions on the reliability of aluminum castings affected by bifilms. Non-HIPed, typical HIPed, and experimentally HIPed A206 castings with bifilms were mechanically tested and microstructurally examined. As a result of HIP, minimum tensile strength increased by nearly a factor of 3, average elongation improved by up to 8 times, and elongations increased from a maximum of 5 to over 18 percent. However, the elongation reliability essentially did not change as a result of HIP, which suggests that healing of bifilms did not occur. Keywords Aluminum, Castings, Bifilms, HIP, Tensile