摘要
目前,Ni-P化学镀层内应力大,结合强度低,耐磨性差,功能单一,不能满足工业应用要求。为此,采用化学镀技术在45钢表面制备了Ni-P功能梯度镀层,并与3种不同磷含量的均质Ni-P镀层对比,研究了镀层硬度、结合力、耐磨性等特征,分析了成分与结构的梯度变化对Ni-P镀层耐磨性能的影响。结果表明:Ni-P梯度镀层的硬度高于中磷和高磷镀层,略低于低磷镀层,400℃热处理1h后其硬度达到最大值;镀层与基体结合紧密;在相同条件下试验,Ni-P梯度镀层的耐磨性均优于均质Ni-P镀层,热处理后其耐磨性比均质Ni-P镀层提高1～2倍;与单层Ni-P镀层相比,梯度镀层在整个磨损过程中摩擦系数变化平稳,波动范围较小,镀层内部成分和结构的梯度化进一步提高了镀层与基体的结合力和耐磨性能。
Three kinds of homogeneous Ni-P coatings with different phosphorus contents and functionally gradient Ni-P coating were prepared by using electroless plating. The hardness, binding strength and wear resistance of the coatings were compar-atively investigated. The effect of gradient composition and micro-structure on the wear resistance of the gradient coating was stud-ied. Result shows that the Ni-P gradient coating has higher hard-ness than homogeneous Ni-P coatings with high and middle P contents, but has lower hardness than homogeneous Ni-P coatings with low P contents. After being heat treated at 400 ℃ for 1 h, the gradient Ni-P coating had the maximum hardness. The gradi-ent Ni-P coating had good binding strength to substrate, and showed better wear resistance than the three kinds of homogene-ous Ni-P coatings under the same test conditions. The wear re-sistance of the gradient Ni-P coating was increased by nearly one to two times after heat treatment. Moreover, the gradient Ni-P coating had a more stable friction coefficient with less fluctuation as compared with the three kinds of homogeneous Ni-P coatings. In general, gradient composition and microstructure contributed to the increasing binding strength and wear resistance of the gradient Ni-P coating.
出处
《材料保护》
CAS
CSCD
北大核心
2010年第3期1-3,10,共4页
Materials Protection
基金
甘肃省中俄国际合作项目(4WS064-A72-053)
中科院"西部之光"项目
中科院"科技支甘"项目
关键词
化学镀
Ni—P梯度镀层
均质镀层
结合力
热处理
耐磨性
electroless plating
Ni-P gradient coating
homogene-ous coatings
binding strength
heat treatment
wear resistance
