COST AFFORDABLE TITANIUM POWDER METALLURGY COMPONENTS

摘要

The solid state powder processing techniques used to process titanium powders and the unique characteristics of ITP powders which improve titanium and titanium alloy component properties will be discussed. Several post processing studies, such as different milling techniques and spheroidization, will be discussed including the effects on powder morphology, bulk density and chemistry. Fully spheroidized CP-Ti powders were able to reach up to 2.90 g/cm~3 (64%) tap density with no impact on powder chemistry. Understanding of the coral-like powder morphology and extraordinary compaction behavior will also be presented (over 150 MPa green strength of compacts uniaxially compacted at 50 TSI). Over 99.6% density was achieved by cold uniaxial pressing and vacuum-sinter for Ti-64 powder at optimized conditions. CP-Ti and Ti-64 were CIPped at 25 TSI compaction pressure into various size billets with the green density of 84% for CP-Ti and 70% for Ti-6A1-4V powders. CIP + Sintered TU6A1-4V billets were sintered at 1300°C for 60 minutes to reach 99% theoretical density. Learning to utilize these titanium powders in conventional powder metallurgy approaches as well as developing new techniques such as spark plasma sintering will allow the ability to achieve near-net shape titanium parts with good properties at lower final costs. Spark plasma sintered Ti-64 compacts have achieved 99.5% density with mechanical properties approaching those of wrought materials.