Production of titanium particulate metal matrix composite by mechanical milling

Mechanical milling is an established production method for aluminium partic ulate metal matrix composites (MMCs). There are examples of its use for hig h performance automotive applications and within the aerospace industry. Th e production of a titanium particulate MMC is still in the developmental st age. However, compared to conventional titanium alloys such materials offer improvements in stiffness, strength, fatigue and creep properties, high te mperature capability, and wear resistance. This paper describes the use of mechanical milling for the production of titanium particulate MMCs with the addition of 10 vol.-%TiB, Gas atomised titanium powders with additions of either boron or TiB2 mere milled in a high purity argon atmosphere to avoid contamination of the powders by oxygen or nitrogen. The distribution of th e boron or TiB2 with increasing milling time is discussed along with the ef fect of the alloy composition. Gas atomised, hydride dehydride, and sponge, fine powder blends are also compared. The powders mere subsequently hot iso statically pressed at 500 degrees C for 2 h at 150 MPa followed by 900 degr ees C for 2 h at 150 MPa, During this consolidation process TiB was formed by an in sitrr reaction between either the TiB2 or boron and the titanium m atrix. MST/4541. (C) Crown copyright 1999. (C) Crown copyright 1999.