• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2017, Vol. 53 ›› Issue (6): 80-87.doi: 10.3901/JME.2017.06.080

• 材料科学与工程 • 上一篇    下一篇

高压油泵凸轮轴激光增材制造梯度耐磨层研究*

石岩, 李云峰, 刘佳, 袁振玉   

  1. 长春理工大学机电工程学院 长春 130022
  • 出版日期:2017-03-20 发布日期:2017-03-20
  • 作者简介:石岩,男,1972年出生,博士,教授,博士研究生导师。主要研究方向为激光加工技术。E-mail:lasercust@hotmail.com李云峰(通信作者),男,1989年出生,博士研究生。主要研究方向为激光加工技术。E-mail:gyhu22@163.com
  • 基金资助:
    * 国家装备预研基金资助项目(51318060104); 20160419收到初稿,20160808收到修改稿;

Research of Gradient Wear-resisting Coating Produced by Laser Additive Manufacturing on High-pressure Pump Camshaft

SHI Yan, LI Yunfeng, LIU Jia, YUAN Zhenyu   

  1. School of Electromechanical Engineering,Changchun University of Science and Technology, Changchun 130022)
  • Online:2017-03-20 Published:2017-03-20

摘要:

为改善高压油泵凸轮轴的耐磨性能与工作可靠性,采用5 kW CO2激光器、四轴联动数控机床及载气式同轴送粉系统等设备对复杂形貌高压油泵凸轮轴进行激光增材制造梯度耐磨涂层工艺研究。通过梯度耐磨涂层结构设计、凸轮边缘防塌陷工装研制与凸轮运动轨迹控制等关键技术的研究,实现了均匀无缺陷且凸轮边缘保护良好的高硬度梯度耐磨涂层的制备。同时,利用扫描电镜、X射线衍射仪、显微硬度计及光学显微镜等分析、测试仪器对梯度耐磨涂层宏观形貌与微观组织进行表征。利用高压喷油泵试验台对激光增材制造与渗碳淬火处理凸轮轴进行使用寿命对比考核测试。结果表明,梯度涂层中主要由γ-Co固溶体、Co3B及M23C6等相组成;其中过渡层与耐磨层还存在WC与W2C形式的增强相,微观组织主要表现为灰白色共晶组织与深灰色枝晶组织;梯度涂层与基体形成良好的冶金结合;增材处理后的凸轮表面耐磨损性能明显提高,使用寿命较渗碳淬火凸轮轴提高约65%。

关键词: 耐磨性能, 梯度涂层, 凸轮轴, 微观组织, 激光增材制造

Abstract:

To improve the wear resistance and operational reliability of high-pressure pump camshaft. The research of gradient wear-resisting coating produced by laser additive manufacturing on complex morphology high-pressure pump camshaft using the 5 kW CO2 laser, four-axis CNC machines and the co-axial powder feeding system. Based on the research of the gradient coating, the edge anti-collapse fixture and the movement control of cam, and realized the preparation of uniform high-hardness gradient coating without defects and the good protection of cam’s edges. The macromorphology and microstructures are characterized by using laser microscope, SEM, XRD and microhardness tester. Comparison tests of service lives of the additive manufacturing camshafts and the cemented quenching camshafts are carried out on the high pressure pump test-bed. The results show that the primary phases of gradient coating are γ-Co solid solution, Co3B, M23C6 and etc. The reinforcing phases are WC and W2C in transition layers and wear-resisting layer. The microstructures of gradient coating contains primary dendrites and interdendritic eutectics. The metallurgical bonding forms well between the gradient coating and the cam. Compared with the cemented quenching camshafts, the useful life of the additive manufacturing camshafts is increased by 65%.

Key words: camshaft, gradient coating, microstructure, wear resistance, laser additive manufacturing