摘要
对汽车发动机热端进行了热喷涂和电接触强化处理,对比分析了Ni60和Ni60/WC涂层在电接触前后以及不同电流作用下的显微硬度和热震性能变化,分析了电接触强化的作用机理。结果表明,在热喷涂后进行电接触强化处理,可以极大提升热端42CrMo基材的抗热震性能;随着电接触电流强度的提高,热震试验过程中出现裂纹的热震次数和产生剥落的热震次数都呈现逐渐增加的趋势;在相同的电接触电流强度下,Ni60/WC涂层出现裂纹的热震次数和产生剥落的热震次数明显更多,具有更佳的抵抗热震的能力,主要与电接触强化作用下涂层与基体之间形成了过渡层有关。
The hot end of automobile engine was treated by thermal spraying and electric contact strengthening, compared and analyzed the microhardness and thermal shock resistance of Ni60 and Ni60/WC coatings before and after electrical contact and under different currents, and the mechanism of electrical contact strengthening was analyzed. The results show that the thermal shock resistance of the hot end 42CrMo substrate can be greatly improved by electrical contact strengthening after thermal spraying; With the increase of electric contact current intensity, the thermal shock times and spalling thermal shock numbers in thermal shock test show a trend of gradual increase; Under the same electric contact current strength, the thermal shock times and spalling thermal shock numbers of Ni60/WC coating are obviously more, and they have more resistance to thermal shock, which are mainly due to the formation of the transition layer under the action of electric contact strengthening.
作者
贾利军
李秀玲
JIA Lijun;LI Xiuling(School of Automotive Engineering,Henan Mechanical and Electrical Vocational College,Zhengzhou 450046,China;Department of Aeronautical Materials,Northwestern Polytechnical University,Xi＇an 710072,China;Contemporary Design and Integrated Manufacturing Technology Key Laboratory of Ministry of Education,Northwestern Polytechnieal University,Xi＇an 710072,China)
出处
《铸造技术》
CAS
2018年第8期1833-1835,共3页
Foundry Technology
关键词
汽车发动机热端
涂层
电接触强化
热震性能
hot end of automobile engine
coating
electrical contact strengthening
thermal shock resistance
