TiAl合金激光表面合金层中TiC凝固生长形态及机制  

Growth morphology and mechanism of TiC carbide in laser surface alloyed composite coating on substrate of TiAl intermetallics

作　　者：陈瑶[1] 王华明[1] 

机构地区：[1]北京航空航天大学材料学院,北京100083

出　　处：《中国有色金属学报》2002年第5期863-868,共6页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目 ( 5 99710 0 3)

摘　　要：利用碳对TiAl金属间化合物合金进行激光表面合金化 ,制得了以TiC (MC碳化物 )为增强相的复合材料涂层 ,研究了MC碳化物的凝固生长形态及生长机制。结果表明 :在激光扫描速度为 6 .0mm/s的凝固条件下 ,MC碳化物呈现微观上具有“小片链状”生长特征的树枝状生长形态 ;当激光扫描速度增加至 16 .4mm/s时 ,其生长形态又转化为具有“三维网络”生长特征的发达树枝晶 ;TiC与Al3TiC reinforced composite coating was fabricated by laser surface alloying on the substrate of TiAl intermetallics. The growth morphology and mechanism of the TiC carbide under rapid solidification conditions were investigated as a function of laser beam scanning speed. TiC carbide under a laser scanning speed of approximate 6.0 mm/s is found to be dendritic having the necklace-like faceted growth characteristic on the dendritic arms. TiC carbide under a laser scanning speed of approximate 16.4 mm/s is in well-developed dendrite having three-dimensional network growth characteristic. The intrinsic lateral growth of MC carbide and the growth kinetics of TiC and Al 3Ti eutectic play an important role in controlling the growth morphology of MC carbide.

关 键 词：MC碳化物 TIC 生长形态 激光表面合金化 TIAL合金 凝固 碳化物 复合材料涂层 生长机制 

分 类 号：TG174.45[金属学及工艺—金属表面处理]