한국주조공학회

The mechanical properties of Ti-Al intermetallic compounds which contain Mn, Zr, or Cr as the third element have been evaluated by means of hardness and compression tests. Microstructures have also been examined using an optical microscope. The cast structures of Ti-Al alloys are coarsened and the lamellar volume fraction is increased by the additions of Mn or V, but the cast structures are refined by the addition of Zr. Hardness tests of room temperature and compression tests at 600℃ showed that the mechanical properties of Ti-Al alloys were mainly dependent on the volume fraction of the α_2 phase, grain size and solid solution hardening. However according to the compression test at 1000℃, the yield strength of Ti-Al alloys decreased with an increase in Mn or Cr content, but increased with an increase in the Zr content.