热处理对Ni-P-Al_2O_3化学复合镀层摩擦磨损性能的影响

Effect of Heat Treatment on Wear Resistance of Electroless Ni-P-Al_2O_3 Composite Coatings

热处理可显著提高镀层的硬度和耐磨性能。采用化学镀的方法在45钢表面制备了Ni-P-纳米Al_2O_3复合镀层,并以不同温度对其热处理,研究了镀层热处理前后的物相、硬度和耐磨性能。结果表明:400℃热处理后,Ni-P-Al_2O_3复合镀层达到稳态,稳定相是Ni+Ni_3P+NiO+Al_2O_3;镀层的显微硬度随热处理温度的升高而先增加后降低;随着镀液中纳米Al_2O_3(n-Al_2O_3)颗粒含量的增加,热处理前后镀层的显微硬度和耐磨性能均先增加后降低;镀液中n-Al_2O_3颗粒含量为2.0 g/L,400℃热处理1h的复合镀层的显微硬度和耐磨性能最佳。

Ni-P-nanometer A1_2O_3 composite coatings were prepared on the surface of 45 steel by electroless plating.As-prepared composite coatings were heat treated under different temperature,and the effect of heat-treatment on the phase structure,microhardness and wear resistance of the composite coatings was investigated.It was found that Ni-P-Al_2O_3 composite coatings reached stabilization after heat-treatment at 400℃,and resultant heat-treated composite coatings consisted of stable phases Ni,Ni_3P,NiO and Al_2O_3.The microhardness of the composite coatings initially rose but declined later on with increasing heat-treatment temperature. Both the microhardness and wear resistance of as-plated and heat-treated composite coatings initially rose but declined later on with increasing content of nanometer Al_2O_3(n-Al_2O_3).The composite coating obtained from the electroless plating bath containing 2.0 g/L n-Al_2O_3 showed the best microhardenss and wear resistance after heat-treatment at 400℃for 1 h.