High-Integrity Titanium Alloy Shapes by Powder Metallurgy
SourceThe use of titanium powder metallurgy (PM) products for high fatigue resistance applications is reevaluated in the light of new developments in titanium alloy powder making, contamination control, consolidation practices, postcompaction heat treatments, and alloy development. Nonmetallic inclusions and lamellar alpha microstructures were identified as contributing to lower fatigue life. The use of clean rotating electrode process (REP) powder and the press consolidation technique (to obtain more uniform low aspect ratio alpha structures) are already producing fatigue strengths as high as those of wrought products. More work is now under way to optimize the use of plasma REP powder (PREP), press consolidation, and alloys specifically designed for powder metallurgy. It is expected that in the very near future, titanium powder metallurgy will produce components of complex shape with lower cost and higher fatigue strength than wrought products.