摘要
采用激光熔覆技术制备了Ni3Al–BaF2/CaF2–Ag基高温自润滑耐磨覆层,考察了覆层在不同温度下的摩擦学性能及高温自润滑机理。结果表明,对复合粉末的预先机械合金化处理,改善了覆层组织的相容性及覆层的摩擦学性能。在室温至800℃的宽温域范围内,覆层的摩擦因数及磨损率分别在0.30～0.34及(2.6～8)×10-5 mm3/m.N之间波动,覆层表现出较平稳的摩擦磨损性能。在中低温度摩擦时,磨损形式主要为微断裂及磨粒磨损;在600℃及以上温度摩擦时,磨损形式受润滑相的热软化与Ni3Al粘结相的摩擦氧化反应共同作用的控制。
The self–lubrication Ni3Al–BaF2/CaF2–Ag metal matrix composite coatings were fabricated on 1Cr18Ni9Ti stainless steel substrates by laser cladding.The friction and wear behavior of the composite coating sliding against Si3N4 ceramic ball from room temperature to 800 ℃ was evaluated using a ball–on–disc friction and wear tester,and worn surface morphologies of the coating were observed using a scanning electron microscopy.It was found that the composition consistent and tribological properties of Ni3Al–BaF2/CaF2–Ag composite coating could be improved pre–milling the composite powders by mechanical alloying.The composite coating has a good friction–reducing and antiwear abilities at elevated temperatures up to 800 ℃.The laser cladding composite coating was dominated by mixed layer detachment and abrasive wear as it slid against the Si3N4 ceramic ball below 600 ℃.With further increase in the test temperature above 600 ℃,it was characterized by softening of BaF2/CaF2 and Ag and oxidization of Ni3Al.
出处
《中国表面工程》
EI
CAS
CSCD
北大核心
2011年第2期51-56,共6页
China Surface Engineering
关键词
激光熔覆
金属基自润滑覆层
摩擦学性能
机理
laser cladding
metal matrix self–lubration coating
friction and wear
mechanism
