铜合金表面激光原位自生W_2C增强镍基涂层

Studies of W_2C in-situ reinforced Ni-based coating prepared by laser cladding on copper substrate

使用脉冲Nd:YAG固体激光器在铜合金表面激光熔覆添加W和C的镍基合金(GH—01)粉末,研究了W_2C硬质相在镍基涂层中的原位自生增强机制.用扫描电镜表征和分析了涂层的显微组织和微区成分,用显微硬度计和X-ray衍射仪分析了涂层的显微硬度变化规律及相关的相组成.结果表明:激光原位反应使镍基涂层组织内原位生成了弥散分布的花瓣状、块状以及柱状的W_2C颗粒,涂层的显微硬度达到了838 HV,是铜基体的8倍.碳化钨的原位生成不但实现了对镍基涂层的强化,而且抑制了裂纹的产生.

W and C added Ni-based alloy （GH-01） powder was cladded on copper substrate by pulsed Nd：YAG laser, and the in--situ reinforced mechanism of W2C hard phase in Ni-based alloy was investigated. The microstructure and composition of the coating were observed and analyzed by scanning electron microscope （SEM）, and the microhardness variation and phases were analyzed by vickers microhardness instrument and X-ray diffraction pattern （XRD）. The results showed that flower shaped, nubbly shaped and column shaped W2C particles formed by in--situ reaction, were dispersed in Ni-based coating. The microhardness of the coating is 838 HV, 8 times of copper substrate.The in-situ formation of tungsten carbide not only reinforces Ni-based coating, but also prevents the formation of cracks.