摘要
Heavy duty engine valve head was prepared by Ni76Cr19AlTi alloy.It was coated by cobalt-base alloy on the surface topromote its wear-resistance.Hardness tester,metallograph,scanning microscopy,energy spectrum and X-ray diffraction were used toanalyze the mechanical properties,the microstructure of the welds and the coated layer of cobalt-base alloy.The results show that thegrains are obviously coasened in the side of Ni76Cr19AlTi alloy in the welds and it contains a typical dentritic structure in the sidecobalt-base alloy.It is found that micro-strain in weld is stronger than that in heat-effected-zone.Micro-strain in nickel-base alloy isstronger than that cobalt-base alloy.There are not obvious imperfects in the weld.Hardness in cobalt-base alloy is more than 390HVand the major carbides in cobalt-base alloy are Cr7C3 and W2C.
Heavy duty engine valve head was prepared by Ni76Cr19A1Ti alloy. It was coated by cobalt-base alloy on the surface to promote its wear-resistance. Hardness tester, metallograph, scanning microscopy, energy spectrum and X-ray diffraction were used to analyze the mechanical properties, the microstructure of the welds and the coated layer of cobalt-base alloy. The results show that the grains are obviously coasened in the side of Ni76Cr19A1Ti alloy in the welds and it contains a typical dentritic structure in the side cobalt-base alloy. It is found that micro-strain in weld is stronger than that in heat-effected-zone. Micro-strain in nickel-base alloy is stronger than that cobalt-base alloy. There are not obvious imperfects in the weld. Hardness in cobalt-base alloy is more than 390HV and the major carbides in cobalt-base alloy are Cr7C3 and W2C.
出处
《中国有色金属学会会刊：英文版》
CSCD
2007年第1期35-40,共6页
Transactions of Nonferrous Metals Society of China
关键词
等离子覆层
排气门
合金
显微结构
机械性能
表面处理
engine valve
nickel-base alloy
cobalt-base alloy
plasma cladding
microstructure
mechanical property
