温度对7A04铝销-50CrMo4钢盘摩擦副干滑动摩擦磨损行为的影响  

Effect of Temperature on Dry Sliding Tribological Behavior of 7A04 Pin-50CrMo4 Disc Contact Pair

作　　者：余梓枫 李迪凡[2] 邵泳林 屈盛官[1] 罗丹 李小强[1] YU Zifeng;LI Difan;SHAO Yonglin;QU Shengguan;LUO Dan;LI Xiaoqiang(National Engineering Research Center of Near-Net-Shape Forming Technology for Metallic Materials,South China University of Technology,Guangdong Guangzhou 510640,China;No.59 Research Institute of China Ordnance Industry,Chongqing 400039,China)

机构地区：[1]华南理工大学国家金属材料近净成形工程技术研究中心,广东广州510640 [2]中国兵器工业第五九研究所,重庆400039

出　　处：《摩擦学学报》2023年第10期1189-1200,共12页Tribology

基　　金：内燃机可靠性国家重点实验室开放基金(skler-201811);广州市科技计划(201807010075)资助。

摘　　要：针对7xxx铝合金温热成型过程中模具磨损等问题,本文作者研究了不同温度对7A04铝销-50CrMo4钢盘摩擦副干滑动摩擦磨损行为的影响.采用光学显微镜、3D光学轮廓仪和扫描电子显微镜等对试样的微观组织、磨痕形貌、磨损亚表层组织以及磨屑形貌进行了表征.结果表明,随着试验温度的升高,摩擦系数先降低后升高.7A04铝销的磨损率先减小后增大;其磨损机制以磨粒磨损为主.50CrMo4钢盘的磨损率先增大后减小,在225℃时降至最低;其室温下的磨损机制为磨粒磨损、胶合黏着磨损和剥层磨损的混合磨损机制,温度从125℃升至175℃时转变为轻微磨粒磨损和一般黏着磨损的混合磨损机制;各温度下均存在明显的材料转移现象.7A04铝销在125℃时开始出现机械混合层,伴随有明显的氧化现象,这将导致在225℃下机械混合层结构变得疏松且易剥落.在225℃下50CrMo4钢磨损亚表面的变形晶粒区和动态再结晶区厚度增大,表面硬度下降,塑性增加,形成长条状的切屑.7A04铝销表面机械混合层的氧化及塑性变形层的变化与50CrMo4钢磨损表面动态再结晶的变化决定了在不同温度中2种材料各具有不同的磨损率与磨损形式.Based on the problems of mold wear in 7xxx aluminum alloy warm forming,the effects of temperature on dry sliding tribological behavior of 7A04 aluminum alloy pin-50CrMo4 low alloy steel disc friction pair were investigated.The worn surface morphology,subsurface microstructure and wear debris were characterized by the optical microscope,3D optical profiler and scanning electron microscope,etc.The results showed that the friction coefficient decreased and then increased as the temperature increased.The wear rate of the 7A04 aluminum alloy pin decreased first and then increased and the main wear mechanism was the abrasive wear.In the process of dry sliding wear,the mechanically mixed layer was observed in the worn subsurface of the 7A04 aluminum pin at 125℃.In addition,there was an obvious oxidation phenomenon in the mechanically mixed layer,which made the structure of mechanically mixed layer looser.The oxidation was also one of the reasons for the increase in the wear rate of 7A04 aluminum pins.At 225℃,the further increasing of the mechanically mixed layer thickness led to the wear rate increasing sharply.The subsurface plasticity of the 7A04 aluminum pin increased slightly due to the deformation and dynamic recrystallization,which also led to increase wear debris size.The wear rate of 50CrMo4 steel increased dramatically first and then decreased to the minimum at 225℃,but there was a significant material transfer phenomenon at all temperatures invariably.During the wear process,the 7A04 aluminum pin separated a large amount of wear debris,which was inserted on the 50CrMo4 disc surface under the vertical load.In the process of dry sliding wear,plastically deformed region and dynamic recrystallization zone generate in the worn subsurface of 50CrMo4 steel disc.With the increase of test temperature,the thickness of the deformed grain zone and dynamic recrystallization zone increased,and the appearance of fine equiaxed grains of dynamic recrystallization enhance the plasticity of the worn surface,which led to th

关 键 词：7A04铝 50CrMo4钢 温度 干滑动磨损 磨屑 

分 类 号：TH117.1[机械工程—机械设计及理论]