Comparison of Blended Elemental (BE) and Mechanical Alloyed (MA) Powder Compact Forging into Ti-6Al-4V Rocker Arms

Abstract

Ti-6Al-4V rocker arms for internal combustion engines were produced by forging of compacts of blended powder consisting of elemental hydride-dehydride (HDH) titanium powder and Al60V40 (wt%) master alloy powder or mechanical alloyed (MA) powder synthesized by high energy mechanical milling of a mixture of HDH titanium and Al60V40 master alloy powders. The powder compacts were made by warm compaction, and their relative density was 90%. The mechanical properties and microstructures of as-forged parts made using blended powder were improved significantly with increasing holding time at forging temperature, and close to those of as-forged parts produced by powder compact forging of HDH Ti-6Al-4V pre-alloyed powder. However, the as-forged part produced by powder compact forging of MA powder was brittle, and fractured prematurely during tensile testing.