热喷涂铝青铜涂层的制备与微动磨损行为*

采用大气等离子喷涂和超音速火焰喷涂在不锈钢表面制备铝青铜涂层,并考察涂层的显微组织、相组成以及微动磨损行为。结果表明,在微动初期涂层接触区内发生轻微损伤,表现为犁沟和粘着;随微动循环次数的增加,层状剥离和氧化成为涂层接触区内的主要损伤形式。超音速火焰喷涂涂层具有更高的致密度和硬度,提高了涂层抗粘着及犁削的性能,故在试验初期表现出较小的摩擦因数和磨损体积;但在微动损伤机制随循环次数增大转变为层状剥离和氧化后,大气等离子喷涂涂层具有更小的摩擦因数和磨损体积。这可能是由于大气等离子喷涂涂层具有更高含量的α相,提高了涂层的韧性抑制了脆性断裂。此外,磨痕内形成的致密氧化层和由应变强化得到的致密化组织减缓了涂层的进一步磨损和氧化。

Fretting Behaviors of Aluminum Bronze Coatings Prepared by APS and HVOF Spraying Technology

Aluminum bronze coatings were prepared on 1Cr18Ni9Ti stainless steel by atmosphere plasma spraying(APS) and high velocity oxy-fuel spraying(HVOF).The microstructure,phase compositions and fretting wear behavior of the coatings were studied.Results show that the main damage of the coatings is plough and slight adhere during the early stage and lamellar stripping and oxidation become the dominate damage mechanism,with increasing fretting cycles.In addition,the HVOF-spraying coating has higher density and hardness,which enhance the resistance against adhesion and plough;therefore it performs better fretting resistance during initial test.But,after the fretting damage converted to lamellar stripping and oxidation,the APS coating performs lower friction coefficient and volume loss.This should be attributed to its higher content of α-phase that enhances the toughness of the coating and suppresses the brittle fracture between splats.Besides,dense oxide layer and strain hardened microstructure relieve the oxidation and wear of the APS coating.