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采用Nd…YAG激光器对阀芯端帽工作面进行激光合金化处理,得到以TiC为主要增强相的激光表面合金层。通过X射线衍射仪、显微硬度计、扫描电子显微镜及能谱仪对合金层的物相组成、显微组织及室温油润滑条件下的耐磨性能进行了检测和分析。结果表明,阀芯端帽工作面激光合金化处理后,合金层的物相主要由马氏体、残余奥氏体、Cr23C6和TiC组成;合金层组织致密,无微裂纹或气孔等缺陷,与基体成良好的冶金结合,显微硬度达358HV,约为基体的1.6倍;合金层的耐磨能力为基体的5.2倍,磨损表面较为光滑,未出现明显的犁沟或剥落。
Nd: YAG laser was used to laser alloyed the working face of the valve core end caps to obtain the laser surface alloy layer with TiC as the main reinforcing phase. The phase composition, microstructure and wear resistance of the alloy under room temperature oil lubrication were tested by X-ray diffraction, microhardness tester, scanning electron microscopy and energy dispersive spectroscopy. The results show that the phase of the alloy layer mainly consists of martensite, retained austenite, Cr23C6 and TiC after the laser alloyed working of the end face of the valve core. The alloy layer has compact structure and no defects such as micro-cracks or pores, The substrate has a good metallurgical bond with a microhardness of 358 HV, which is about 1.6 times that of the matrix. The wear resistance of the alloy layer is 5.2 times that of the matrix, and the wear surface is relatively smooth with no obvious furrows or flaking.