Al2O3对Ni60激光熔覆层组织和耐磨性的影响

采用自动送粉激光熔覆技术,在A3钢表面进行了Ni60合金添加Al2O3的激光熔覆试验,通过对工艺参数和Al2O3含量的选取,获得了性能改善的激光熔覆层。对熔覆层横截面进行了硬度测试和显微组织分析,对熔覆层表面进行了X射线衍射物象分析和摩擦磨损试验。结果表明:与纯Ni60激光熔覆层相比,添加适量Al2O3的Ni60激光熔覆层的平均硬度提高300Hv0.3,耐磨性提高4倍。分析认为,Al2O3能够大大提高Ni60激光熔覆层硬度和耐磨性的原因在于:适量Al2O3的加入,可抑制涂层中粗大的脆性硬质相的形成,起到细化晶粒的作用:而形成的Al2Cr4C2细小颗粒增强相均匀弥散分布在组织中,不容易脱落,很好的起着均匀载荷和减摩抗磨作用。

Effect of Al2O3 on the microstructure and wear properties of laser-clad Ni60 alloy coatings

The experiments of laser cladding of Ni60 alloy powder doped with Al_2O_3 have been carried out by various laser processing parameters and different Al_2O_3 contents selected to achieve property improvement clad layers.The micro-hardness testing and microstructure observation have been completed on the cross-section of the laser-cladding zone.The X-ray diffraction analysis and the friction wear test of the surface of the laser coatings have been accomplished.The results show that the average hardness of laser cladding doped with suitable content Al_2O_3 increase 300 Hv_(0.3) and wear resistance adds up 5 times compared with Ni60 coatings.By analysis that the addition of Al_2O_3 can enhance the hardness and wear properties of coatings is due to that a proper Al_2O_3 content added to can suppress the formation of big needle brittle hard phases and refine the structural grains,the formed phase of Al_2Cr_4C_2 homogenous distribution in the structure can'-t easily take off and play an important part of wear reduction and wear resistance.