摘要
通过在ZL109活塞表面制备Ni60和Ni60+5%La_2O_3熔覆层,对比分析了活塞基材和熔覆层在1.2 mol/L硫酸溶液、3.5%氯化钠溶液和1.2 mol/L氢氧化钠溶液中的电化学性能,并对熔覆层显微形貌和腐蚀形貌进行了观察。结果表明,在熔覆层中添加5%La_2O_3后,La元素少量固溶于熔覆层基体,而大部分以颗粒状析出相的形式存在熔覆层中,添加5%La_2O_3可以细化枝晶组织和消除显微气孔缺陷;活塞基材、Ni60和Ni60+5%La_2O_3熔覆层在3种不同腐蚀介质中的耐腐蚀性能变化趋势一致,即Ni60+5%La_2O_3熔覆层具有最佳的耐腐蚀性能,其次为Ni60熔覆层,而活塞基材的耐腐蚀性能最差。因此,可以通过表面激光熔覆Ni60+5%La_2O_3提高汽车发动机活塞的耐腐蚀性能。
The Ni60 and Ni60＋5%La2O3cladding layer on the surface of the piston ZL109 alloy were prepared,comparative analysis the electrochemical properties of the piston base material and the cladding layer in 1.2 mol/L sulfuric acid solution,3.5%sodium chloride solution and 1.2mol/L in sodium hydroxide solution,and the microstructure and corrosion morphology of the cladding layer were observed.The results show that there is a small amount of La element solid solution in the substrate and the cladding layer with adding 5%La2O3,the most of the granular precipitates existed in the laser cladding layer,the addition of 5%La2O3can refine the dendrite and eliminate the porosity defects.The corrosion resistance of piston base material,Ni60 and Ni60＋5%La2O3cladding layer in 3 different corrosion media are in accordance with each other,the Ni60＋5%La2O3coatings have the best corrosion resistance,the Ni60 cladding layer is followed,the corrosion resistance of substrate piston is the worst.Therefore,the corrosion resistance of automotive engine piston can be improved by surface laser cladding of Ni60＋5%La2O3.
作者
王立超
李振
谢小军
WANG Lichao1, LI Zhen2, XIE Xiaojun3(1. School of Automotive Engineering, Changchun Automobile Industry Institute, Changchun 130013, China; 2. School of Materials Science and Engineering, Jilin University, Changchun 130012, China; 3. Department of Materials Engineering, Changchun University of Science and Technology, Changchun 130022, Chin)
出处
《铸造技术》
CAS
2018年第4期910-913,920,共5页
Foundry Technology
