铝活塞环槽表面Ni-SiC耐磨涂层的制备及性能试验研究

Preparation and property test of functionally Ni-SiC wear resistant coating on the surface of aluminum piston ring groove

为了提高活塞环槽的硬度和耐磨性能,采用共沉积技术在活塞一环槽部位制备Ni-SiC耐磨涂层。研究表明,当电流密度为5 A/dm^2时,涂层生长速度最快且没有外观缺陷;电镀液温度为50~60℃时,涂层的内应力最稳定;电镀液的pH值为4~5时,制备的涂层质量最好;搅拌速度为250 r/min时,涂层中的共沉积颗粒的含量最高、颗粒分布最佳。分析涂层的硬度、摩擦磨损性能可知,制备的Ni-SiC涂层能够均匀地覆盖在基材表面,涂层最外层HV硬度可达700~800,耐磨性能是硬质阳极氧化铝涂层的2~3倍。对使用该涂层的活塞进行额定工况试验和对比试验,结果表明:涂层完好无脱落,磨损量符合要求。

In order to improve the hardness and wear resistance of piston ring groove,the Ni-SiC wear-resistant coating is prepared on the piston ring groove by co-deposition technology.The results show that the coating grows the fastest and has no appearance defects when the current density is 5 A/dm^2,the internal stress of the coating is the most stable when the temperature of the transition fluid is 50~60℃,the coating quality is the best when the pH of electroplating solution is 4~5,when the stirring speed is 250 r/min,the content of co-deposited particles reaches the maximum and the best particle distribution.Through the analysis of the hardness and friction and wear properties of the coating,it can be seen that the prepared Ni-SiC coating is evenly covered on the surface of the substrate,the HV hardness is 700~800,and the wear resistance is 2~3 times of that of the same thickness hard anodized aluminum.The rated condition tests and comparative tests results show that the coating is in good condition without cracking and the wear amount meets the requirements.