工艺参数对TiAl合金激光表面合金化改性层组织与耐磨性的 …

利用元素氮和元素碳对γ－ＴｉＡｌ合金（简称ＴｉＡｌ合金）进行激光表面合金化处理，分别制得了以ＴｉＮ及ＴｉＣ硬质耐磨相为增强相的快速凝固原位耐磨复合材料表面改性层，改性层与基体间为完全的冶金结合，其显微组织从熔池底部到自由表面具有梯度渐变特征，越接近自由表面，增强相越密集，较系统地研究了激光表面合金化工艺参数对改性层显微组织以及在磨料磨损及滑动磨损条件，增强相越密集。较系统地了激光表面合金化工艺参数

Effects of processing parameters on microstructure and wear resistance of laser surface alloyed layer on TiAl alloy

Laser surface alloying with nitrogen and carbon were employed to produce modified layers on TiAl alloy. The rapidly solidified in situ composites layers reinforced by titanium nitride and titanium carbide were gained respectively, and the interfaces between the layers and substrate were metallurgic bonds. From bottom of molten bath to free surface, there was gradient change characteristic in microstructures. The nearer the free surface, the higher the volume fraction of reinforced phase. The effects of laser processing parameters on microstructures and wear resistance of surface alloyed layer were studied. With decreasing laser beam scanning rate, the volume fraction of reinforced phase increases, the microhardness of the samples increases and the wear resistance is improved. [