Friction and Wear Performances of Ni-P Coatings by Chemical Plating after Crystallization Treatment

摘要:

利用化学镀在YL113铝合金表面制备了非晶态Ni-P镀层，通过SEM、EDS和XRD等手段表征了其在不同温度下晶化处理后表面形貌、化学元素含量和物相组成。分析了晶化处理温度对镀层硬度的影响，并用HSR-2M型往复摩擦磨损试验机考察了Ni-P镀层磨损机制。结果表明，当晶化处理温度升高时，镀层晶粒尺寸逐渐增大，镀层中形成了以Ni为主的化合物，在350 ℃时硬度最高；350以后，如果晶化温度继续升高，晶粒尺寸增大，表现出以Ni的衍射峰强度增加的反霍佩琪效应；随晶化处理温度升高，镀层摩擦系数先增大后减小，在350 ℃时摩擦系数最小，磨损性能最好。晶化处理温度低于350 ℃、在350 ℃、高于350 ℃时的磨损机制分别为磨粒磨损、粘着磨损+磨粒磨损、粘着磨损

Abstract:

Amorphous Ni-P coating was prepared on the surface of ZL113 aluminum alloy by electroless plating. The surface morphologies, chemical element contents and phase compositions of the coating at different crystallization temperatures were characterized by SEM, EDS and XRD, respectively. The effect of crystallization temperature on coating micro-hardness was analyzed, and the wear mechanism was investigated with HSR-2M type reciprocation friction abrasion tester. The results show that the grain size of Ni-P coating increases with the increases of crystallization temperature, Ni based compounds are formed in the coating, and the hardness is the highest at the temperature of 350 oC. After 350 oC, if the crystallization temperature increases continuously, and the grain size increases a little fast a reverse effect of Hall-Petch with the intensity of Ni diffraction peak increasing is shown. The friction coefficient increases first and then decreases with the increases of crystallization temperature. The friction coefficient is minimum, and the wear resistance is the best at 350 oC. The wear mechanism is abrasive wear, abrasive＋adhesive wear and abrasive wear at the crystallization temperatures less than 350 oC, 350 oC, more than 350 oC, respectively