摘要
目的 优化Ni60+WC激光熔覆工艺参数,提高熔覆层质量。方法 设计三因素四水平正交试验,通过激光熔覆手段,在Q235钢板表面激光熔覆Ni60+25%WC粉末,并结合超景深光学显微镜和扫描电子显微镜观察熔覆层形貌。同时,以熔覆层几何形貌和气孔率作为优化目标,评估工艺参数对其的影响。结合灰色关联理论,对熔覆层最佳工艺参数进行预测,并进行试验验证。结果 优化后的熔覆层主要以胞状晶为主,且熔覆层和基体形成了良好的冶金结合。采用田口-灰色关联法对激光熔覆工艺参数进行优化,极大地减少了试验次数(从64次减少到16次)。灰色关联度的预测值(0.626 553)与试验验证值(0.672 659)有较高的吻合度,误差仅为7%。优化后的工艺参数组合为激光功率1100W,扫描速度为10mm/s,送粉速率为7.6 g/min。优化后的熔覆层宽度增加了22%(1 949μm增加到2 383μm),稀释率降低了58%(24.42%降低至10.33%),优化后的稀释率更接近目标值10%。同时,气孔率也降低了7%(0.329%降低至0.306%)。优化后的熔覆层润湿角仍小于70°,符合优化目标。结论 田口-灰色关联法能极大地减少试验次数,并较为准确地实现激光熔覆工艺参数的预测优化,有效提高熔覆层的质量,为解决复杂多响应问题的参数优化提供了一种有效手段。
Laser cladding is a new surface modification technology.It has the characteristics of fast cooling rate,small heat affected zone,wide powder selection range and high degree of automation.Cladding parameters have a significant impact on the geometric morphology and porosity of the cladding layer,which is an important factor affecting the quality of the cladding layer.At present,the researches on laser cladding process parameters are mainly based on the experiments to improve the mechanical properties of the cladding layer.However,there are few studies on optimizing the porosity and improving the quality of cladding layer.Moreover,the statistical analysis is also needed.Therefore,in the present study,Taguchi-Grey relation method was used to systematically analyze the effect of the cladding parameters,and the cladding parameters of Ni60+25%WC were optimized.The substrate(Q235)was cut into 100 mm×100 mm×10 mm square plates,and the MobiMRO fiber laser was used for this study.After the experiment,the sample was cut with wire cutting and polished.Finally,the sample was corroded with aqua regia.Taguchi method was used in the present study to design a three-factor and four-level orthogonal experiment,which greatly reduced the number of the experiments(from 64 to 16)and reduced the experiment cost.At the same time,the cross section geometry,porosity and microstructure of the cladding layer were observed by the optical microscope and scanning electron microscope.The cladding width,the cladding height,the area of the cladding layer,the area of the cladding depth,the pore area and the grain size of the cladding layer were measured by the VHXAnalyzer software and PhenomImageViewer software.With the geometry(cladding width,cladding height,dilution ratio)and the porosity of the cladding layer as the response indexes,the effects of the specific energy and the powder feeding rate on the cladding width,the cladding height,the dilution ratio and the porosity were analyzed.Then,combined with the signal-to-noise ratio analysis,the e
作者
姚鑫宇
林强
丁昊昊
王文健
郭俊
祝毅
甘露
YAO Xin-yu;LIN Qiang;DING Hao-hao;WANG Wen-jian;GUO Jun;ZHU Yi;GAN Lu(Tribology Research Institute,State Key Laboratory of Traction Power,Southwest Jiaotong University,Chengdu 610031,China;State Key Laboratory of Fluid Power and Mechatronic Systems,Zhejiang University,Hangzhou 310058,China;Chengdu Qingshi Laser Technology Co.,Ltd.,Chengdu 610213,China)
出处
《表面技术》
EI
CAS
CSCD
北大核心
2023年第11期394-405,465,共13页
Surface Technology
基金
国家自然科学基金(52205578)
四川省区域创新合作项目(2022YFQ0113)
载运工具与装备教育部重点实验室开放课题(KLCE2021-10)。
关键词
激光熔覆
镍基WC
工艺参数优化
田口-灰色关联法
信噪比分析
几何形貌
气孔率
laser cladding
nickel based WC
parameter optimization
Taguchi-grey relation method
signal to noise ratio analysis
geometric morphology
porosity
