γ-TiAl合金激光表面气相氮化层的组织与性能

Microstructure and Property of Laser Gas Nitriding on γ-TiAl Alloy

通过激光气相合金化技术在γ TiAl铸态合金表面“原位”制得以高硬度高耐磨氮化物为增强相的金属基复合材料表面改性层。运用SEM ,XRD和TEM对改性层的微观组织转变进行了研究。结果表明 :激光气相氮化改性层内的显微组织由α ,γ ,TiN和Ti2 AlN组成 ,沿层深呈不均匀分布。改性层的显微硬度最高可达 10 0 0kg/mm2 ,约为基体硬度值的两倍。

Composite modification layer on γ-TiAl alloy could be available by laser gas nitriding technique which was reinforced by nitrides. The microstructure characteristics of nitriding layer were investigated through SEM, XRD and TEM examination. It is consisted of α, γ, TiN and Ti 2AlN and is inhomogeneous distributed throughout the nitriding zone. The maximum hardness value reaches to 1000 kg/mm 2 and is double that of the matrix one. The effect of nitriding on micro-hardness was also discussed.