Ti6A14V合金的激光气体氮化

Laser Gas Nitriding of Ti6A14V Alloy

采用高功率连续波Nd YAG激光在Ti6A14V合金表面进行激光气体氮化,获得了均匀致密、无孔洞裂纹等缺陷的氮化钛改性层。用扫描电镜、X射线衍射仪、显微硬度计及磨损试验机研究了气体氮化层的组织特征和摩擦磨损行为。结果表明:反应生成的细密TiN枝晶密度由表及里呈梯度分布,激光氮化层的硬度可达Hv0.21500,气体氮化层明显改善了Ti6A14V合金的磨损性能,提高2.8倍。

Laser surface gas nitriding is an attractive method to enhance surface hardness and wear resistance of Ti6A14V alloy.Laser gas nitriding processing of the Ti6A14V alloy was investigated by using a 2 kW continuous wave Nd-YAG laser under an N_2 environment.In the laser affected zone,neither micro-cracking nor porotic structure were observed.SEM and XRD were carried out for laser surface gas nitrided characterization and ball-on-disk tests were conducted to measure the abrasive wear behavior of the resulting surfaces.The results of examination showed that the density of a fine dendritic structure was distributed with grads from surface to inside,microhardness of laser nitration case is Hv_(0.2) 1 500.The wear performance of Ti6A14V was improved obviously.