中國有色金屬學報(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 12 No. 6 December 2002 |
WANG Hong-wei(王宏偉)1,ZENG Song-yan(曾松巖)1
（1. School of Materials Science and Engineering,Harbin Institute of Technology,
Harbin 150001, China;
2. School of Materials Science and Engineering,
Harbin Institute of Technology,Weihai 264209, China）
Abstract:XDTMmethod was used to prepare titanium aluminide(Ti3Al) matrix composites. The phase constitution and the as-cast microstructure of Ti-25Al alloy with different carbon contents have been investigated using XRD and SEM. Microhardness and elastic modulus of the matrix and reinforcements were tested by mechanical property microprobe. In Ti-25Al-0.5C alloy, blocky Ti3AlC and lath Ti3AlC were in-situ formed as reinforcement, and homogeneously distributed in the matrix. The microhardness and elastic modulus of blocky Ti3AlC are 14.2GPa and 281.3GPa respectively, higher than those of the lath Ti3AlC about 3GPa and 60GPa respectively. When C content is more than 0.5%, dendritic TiC and Ti3AlC were formed as reinforcement in a core structure, where the TiC core is coated with Ti3AlC phase. The microhardness and elastic modulus of the reinforcement decrease with increasing distance from the center of the reinforcement and matrix. The maximum microhardness and modulus of TiC and Ti3AlC are 22.8GPa, 302.7GPa and 20.2GPa, 313.5GPa, respectively.
Key words: Ti3Al; Ti3AlC; TiC; microhardness; elastic modulus
