ALUMINUM CO OF AMERICA ALCOA CENTER PA PHYSICAL METALLURGY DIV
Six PM alloy-powders were prepared for this vacuum-preheat process verification. PM 2-in. diameter extruded rod for extrusion evaluation was fabricated from vacuum preheated and hot pressed VAC-preheat compacts. Camparison ingot metallurgy IM 7050 extrusions were also prepared. Preliminary test results show PM alloys MA86, MA87, MA89 and MA67 developed good transverse fracture toughness and ductility, with transverse fracture toughness comparable to that achieved in VAC-preheat MA83 alloy. This verified the reproducibility of the fracture toughness improvement previously indicated for VAC-preheat over inert-gas FCE preheat. PM 4-in. diameter extruded stock for die forging was fabricated from VAC-preheated 140-lb compacts. Comparison IM 7050 extruded rod was also prepared.