LaF_3对激光原位合成TiC/Ni涂层耐蚀性的影响

以Ni60、Ti、石墨、Mo及La_3为原料,在闸板表面激光熔覆原位合成了TiC/Ni复合涂层.利用SEM、电化学腐蚀系统对涂层组织和耐蚀性能进行分析.结果表明,未添加LaF_3,和添加3%LaF_3的熔覆层中存在异质相.自腐蚀电流升高,腐蚀电位降低,耐蚀性下降;添加2%LaF_3的熔覆层中异质相消失,腐蚀电流密度降低,腐蚀电位升高,钝化区宽度增加,耐蚀性提高.

Effect of LaF_3 on Corrosion Resistance of TiC/Ni Coating Prepared by Laser Cladding In-situ Synthesis

The TiC/Ni composite coating was prepared by laser cladding in-situ synthesis on the surface of damper plate with Ni-Cr-Ti-C-LaF_3 powder.Micmstrueture and corrosion resistance were studied through SEM and M352 electrochemistry corrosion system.The result shows that both the coating without LaF_3 and the coating with 3%LaF_3 have the heterogeneous phase;the corrosion current of the two coating elevates,the corrosion potential and corrosion resistance reduces.The laser cladding with 2%LaF_3 has no heterogeneous phases,which reduces the corrosion current,elevates the corrosion potential and increases the width ofpassivation area.So the corrosion resistance improves.