Press-and-sinter processing of a PM counterpart to wrought aluminum 2618

Abstract

The objective of this research was to develop a powder metallurgy (PM) counterpart to the wrought aluminum alloy 2618 utilizing press-and-sinter technology. Each starting blend was prepared from a strategic combination of prealloyed aluminum coupled with elemental and master alloy additions and was processed through uni-axial die compaction coupled with controlled atmosphere sintering. All of the PM alloys responded well to sintering with near full theoretical density realized. The most desirable PM product contained minor additions of tin and silicon. Whereas tin imparted enhanced densification, silicon promoted appreciable gains in hardness and tensile properties. It was also determined that the beneficial effects of silicon persevered after prolonged thermal exposure at 260°C provided that a nominal concentration of 0.2wt% was maintained. The final press-and-sinter PM product offered mechanical properties and thermal stability that were comparable to the wrought target.