Dongtao JIANG and Jianting GUO (Institute of Metal Research
,
Chinese Academy of Sciences
,
Shenyan 110015
,
China)
材料科学技术（英）
A novel in-situ multiphase NiAl-based composite was investigated on its microstructures and properties influenced by HIP treatment. In the as- processed composites, a fine array of NiAl precipitates was found to be distributed in Cr(Mo) phase. TiC particles tended to segregate at grain or phase boundaries. In addition, a number of dislocations were observed to exist in NiAl grains meanwhile fewer in Cr(Mo) grains. Little change in the morphology was found except that nearly fully densification was achieved. Some changes in microstructures were notable including coarsening of NiAl precipitates in Cr(Mo) phase and increase in dislocation density in NiAl phase.After HIP, the strength of the composites increased significantly compared with the as-processed composites. The reason for the enhanced Strength of the composites is also discussed.
关键词:
C.H. Zhou
,
K. Yang and Y.X. Lu (Liaoning Key Lab for Hydrogen and Materich
,
Institute of Metal Research
,
The Chinese Academy of Sciences
,
Shenyan 110015
,
China)
金属学报(英文版)
In order to alleviate the severe interface reaction, which is likely to occur during the fabrication of continuous SiC fiber reinforced titanium matrix composite, hydrogen was temporarily introduced in the fabrication to lower the consolidation temperature of Ti/SiC composites in the present work. Effects of different fabrication conditions, with or without hydrogen, on the bonding state and the matrix microstructure were investigated. In-situ hydrogenation method was found to larpely improve the interface bonding of the composite, and full consolidation could be achieved at 750 or even 700° C more than 100°C lower than the normal fabrication temperature of Ti/SiC composite, which consequently reduced the interfacial reaction layer between Ti matrix and SiC fiber. Different hydrogenation condition led to different matrix microstructure. In order to avoid the embrittling effect of residual hydrogen on the composite,Ti/SiC composite needs to be held in vacuum at the fabrication temperature for longer time after consolidation.
关键词:
Ti/SiC composite
,
null
,
null
