DZ125合金表面Al-Ce-Y渗层的组织与摩擦磨损性能

Microstructure and Wear Resistant Properties of Al-Ce-Y Coatings Prepared on DZ125 Alloy

采用扩散共渗法在DZ125合金表面制备了Ce-Y改性渗Al涂层,分析了涂层的组织结构和形成机制,对比研究了DZ125合金基体及涂层在20、300和600℃时的摩擦磨损行为。结果表明,经950℃保温2h所制备的Ce-Y改性渗Al涂层厚约125μm,组织致密,主要由Al_3Ni_2、Al_3Ni和Cr_7Ni_3相组成。Ce-Y改性渗Al涂层在20和600℃时的耐磨性能优于DZ125合金,但在300℃时其耐磨性能低于基体合金。在20℃磨损时,DZ125合金的磨损机理为剥层磨损和轻微的磨粒磨损,Ce-Y改性渗Al涂层为表面擦伤;30 0℃时DZ125合金表现为粘着磨损、剥层磨损和磨粒磨损,Ce-Y改性渗Al涂层为剥层磨损及磨粒磨损;当温度为600℃时,二者均为剥层磨损和磨粒磨损。

Ce-Y modified aluminum coatings were prepared on DZ125 alloy by pack cementation processes at 950 ℃for 2 h.The microstructure and formation mechanism of the coatings were investigated.The friction-wear properties of the DZ125 alloy and the coatings were analyzed comparatively at 20 ℃,300℃ and 600℃.The results show that the prepared Ce-Y modified aluminum coatings with a thickness about 125μm exhibit compact,which mainly consist of Al3Ni2,Al3Ni and Cr7Ni3.The Ce-Y modified aluminum coatings have the more superior anti-friction behavior than DZ125 alloy with sliding at 20 ℃and 600 ℃,while the opposite results can be observed with sliding at 300℃.Sliding at 20℃,the wear mechanisms of DZ125 alloy are characterized by delamination wear and slight abrasive wear,while those of the Ce-Y modified aluminum coating are surface scratches.The wear mechanisms of DZ125 alloy are turned to be delamination wear,adhesive wear and abrasive wear,and those of the Al-Ce-Y coating are characterized by delamination wear and abrasive wear when the sliding temperature is increased up to300 ℃.Sliding at 600℃,the dominated wear mechanisms of both substrate and the coating can be concluded as delamination wear and abrasive wear.