耐磨性的影响
(华南理工大学 机械工程学院，广州 510641)
摘 要: 研究铝合金化学镀Ni-W-P三元合金的耐磨性能，探讨钨含量对铝合金(LY12)化学镀Ni-W-P耐磨性和硬度的影响。结果表明：铝合金表面化学镀Ni-W-P三元合金在400 ℃加热1 h后，表面硬度达HV251 080，表面硬度和耐磨性均较基体提高10倍以上；但过高的W含量，使得表面硬度下降。磨损实验发现，试样产生了镀层碎裂和剥落现象。其主要原因是由于铝合金基体与镀层热膨胀系数的差异及Ni3P的析出导致应力过大，引起镀层硬度和耐磨性随着W含量的增加而下降。并用化学镀Ni-W-P合金沉积机理解释了镀层成分分布特征的形成原因。
关键字: Ni-W-P合金；化学镀；耐磨性
of electroless Ni-W-P plating on aluminium alloy
（College of Mechanical Engineering, South China University of Technology, Guangzhou 510641, China）
Abstract:The wear resistance of electroless Ni-W-P coatings on aluminium alloy was studied, the effect of content of tungsten on the wear resistance and hardness of electroless Ni-W-P deposits was discussed. The results show that the hardness of deposit heated at 400 ℃ for 1 h is HV251 080, and the wear resistance and hardness of deposits heated at 400 ℃ for 1 h are ten times more than those of aluminium matrix. With increasing content of W, the hardness of Ni-W-P coatings decreases. Disintegration and spall on the Ni-W-P deposits heated at 400 ℃ for 1 h were generated after abrasion test because of the excessive stress caused by different coefficient of thermal expansion between matrix materials and deposits and precipitation of Ni3P. The characteristic of electroless Ni-W-P deposits composition distribution is explained by aggradational deposition mechanism of electroless Ni-W-P deposits.
Key words: Ni-W-P alloy; electroless plating; wear resistance
