2002 年 43 巻 9 号 p. 2331-2336
A Chromium (Cr) containing TiAl intermetallic has been consolidated by Hot Isostatic Pressing (HIP) process using high purity TiAl pre-alloyed powder as original material. Cr has been selected as an element which improves high temperature mechanical properties of HIPed TiAl intermetallic compound. Cr additions in TiAl powder were changed systematically and microstructure and mechanical properties at elevated temperatures were examined. This study determined the densification behavior of Cr containing TiAl intermetallic powder during HIP process conducted at 1273 K under the pressure of 200 MPa. Microstructure of consolidated TiAl+xCr as well as high temperature mechanical properties are presented. Improvement of high temperature tensile strength of as-HIPed TiAl compound was achieved by the effect of Cr particles dispersion and reactive zone formation between Cr particles and TiAl matrix. From these results, it was concluded that tensile strength of HIPed TiAl–5Cr becomes 1.2–1.5 times high than that of HIPed and MIMed TiAl and machinability of TiAl at R.T. also was improved by high elongation of HIPing and Cr addition.
