激光功率对TC4合金表面Ni60A/CeO2熔覆层组织及耐腐蚀性能的影响

为了提高TC4合金基体表面的耐腐蚀性能,运用激光熔覆同轴送粉技术,采用1200、1500、1800、2100、2400 W等不同激光功率在TC4合金基体表面上制备Ni60A/CeO₂复合熔覆层,对熔覆层进行了显微组织观察、电化学检测以及电化学腐蚀后的表面观察,探究激光功率对熔覆层耐腐蚀性能的影响。研究表明,随着激光功率的增加,熔覆层的显微组织变得排布均匀且细密,电化学特性呈现出耐腐蚀性先增大后减小的特点。当激光功率为2100 W时,电化学阻抗最大,为25.74 km²,熔覆层表面并未出现明显的腐蚀隧道,大部分为腐蚀产物覆盖在Ni60A/CeO₂熔覆层的表面,耐腐蚀性良好。

Effect of laser power on microstructure and corrosion resistance of Ni60A/CeO2 clad layer on TC4 alloy

In order to improve the corrosion resistance of the TC4 alloy substrate surface, Ni60A/CeO₂ composite clad layers were prepared on TC4 alloy substrate surface by laser cladding coaxial powder feeding technology with different laser power of 1200, 1500, 1800, 2100 and 2400 W. The effect of laser power on the corrosion resistance of the clad layer was studied by microstructure examination, electrochemical detection and surface observation after electrochemical corrosion. The results show that with the increase of laser power, the microstructure of clad layer becomes uniform and fine, and the electrochemical characteristics show that the corrosion resistance first increases and then decreases. When the laser power is 2100 W, the maximum electrochemical impedance can reach 25.74 kΩ·cm², and there is no obvious corrosion tunnel on the surface of the clad layer, with most of the corrosion products covering the surface of Ni60A/CeO₂ clad layer, and the corrosion resistance is good.