45钢轴面激光熔覆Ni60AA涂层工艺参数优化及摩擦磨损性能研究  

Parameters Optimization and Friction and Wear Properties for Laser Cladding Ni60AA Coating on 45 Steel Shaft Surface

作　　者：吴军 朱冬冬[1,2] 杨日初 吴思宇[1] 黄燕 张玉良 Wu Jun;Z hu Dongdong;Yang Richu;Wu Siyu;Huang Yan;Zhang Yuliang(Department of Mechanical Engineering,Quzhou University,Zhejiang Quzhou 324000,China;Key Laboratory of Air-Driven Equipment Technology of Zhejiang Province,Zhejiang Quzhou 324000,China)

机构地区：[1]衢州学院机械工程学院,浙江衢州324000 [2]衢州学院浙江省空气动力装备技术重点实验室,浙江衢州324000

出　　处：《激光与光电子学进展》2021年第11期296-306,共11页Laser & Optoelectronics Progress

基　　金：国家自然科学基金(51501100,51801112);浙江省自然科学基金(Y18E010003)。

摘　　要：为提升45钢轴类零件的使用寿命,本文开展了Ni60AA涂层激光熔覆工艺参数优化研究。采用多道螺旋搭接工艺路径开展轴面熔覆工艺试验,即在45钢轴面上制备Ni60AA合金熔覆层。基于单一变量法分别对激光功率、送粉速率、轴转速这3个工艺参数开展多道单因素熔覆试验,并以熔覆层厚度、稀释率、显微硬度为涂层质量评价指标初选工艺参数。基于单因素试验进一步开展三因素三水平正交试验,利用权矩阵分析法对熔覆工艺参数进行多目标综合优化,并对优化后熔覆层的显微组织和硬度进行分析。同时,在不同温度下对熔覆层进行摩擦磨损试验,分析了熔覆层的摩擦因数、磨损率及磨痕形貌,验证了工艺优化方案的可行性。送粉速率对考察指标的综合影响最大,激光功率的综合影响次之,轴转速的综合影响最小;最优工艺参数为激光功率1400 W,送粉速率16.3 g/min,轴转速2.3 r/min。熔覆层厚度及显微硬度较工艺优化前分别提升了3.49%和2.8%。当试验温度为35,80,125℃时,熔覆层的平均摩擦因数比基体45钢分别低28.5%、21.1%、11.8%,磨损率比基体45钢分别低87.6%、86.6%、80.9%。对激光熔覆工艺参数进行优化可以获得成型质量较好、硬度和耐磨性显著提升的Ni60AA熔覆层。To improve the service life of 45 steel shaft parts, we aim to study optimum process parameters of laser cladding Ni60 AA coating on 45 steel shaft surface. The cladding process test of shaft surface was carried out with multi-pass spiral lap technology, namely, a Ni60 AA alloy cladding layer was prepared on a 45 steel substrate. Based on the single variable method, the single factor cladding experiments were carried out on three process parameters,namely laser power, powder feeding rate and shaft speed. The thickness of cladding layer, dilution ratio and microhardness were selected as the evaluation indexes of coating quality. Based on the single factor experiment, the orthogonal experiment of three-factor and three-level was completed. The multi-objective comprehensive optimization of the process parameters was finished by the weight matrix method, and the microstructure and micro-hardness of the optimized cladding coating were analyzed. At the same time, friction and wear experiments were carried out at different working temperatures, and the friction coefficient,wear rate and wear scar morphology were analyzed and the feasibility of process optimization is verified. Powder feeding rate has the largest comprehensive influence ability, followed by laser power and shaft speed. The optimal parameters are laser power of 1400 W,powder feeding rate of 16. 3 g/min, and shaft speed of 2. 3 r/min. The thickness and micro-hardness of the cladding coating were increased by 3. 49% and 2. 8% respectively compared with those before optimization. When the test temperature is 35, 80 and 125 ℃, the average friction coefficient of the cladding coating is 28. 5%, 21. 1% and11. 8% lower than that of 45 steel and the wear rate of the cladding coating is 87. 6%, 86. 6% and 80. 9% less than that of the substrate. Ni60 AA cladding coating with high forming quality and significantly improved hardness and wear resistance can be obtained by optimizing the laser cladding process parameters.

关 键 词：激光技术 激光熔覆 Ni60AA熔覆层 正交试验 权矩阵分析法 摩擦因数 

分 类 号：TG174.4[金属学及工艺—金属表面处理]