超声辐射对激光熔覆Ni基WC涂层性能的影响  

Effect of Ultrasonic Radiation on the Properties of Laser Melted Ni-based WC Coatings

作　　者：赵昌龙[1] 杜伟龙 于子策 张自豪 白宇阳 张书豪 董博 杨俊宝 ZHAO Changlong;DU Weilong;YU Zice;ZHANG Zihao;BAI Yuyang;ZHANG Shuhao;DONG Bo;YANG Junbao(School of Mechanical and Vehicle Engineering,Changchun University,Changchun 130022,China)

机构地区：[1]长春大学机械与车辆工程学院,长春130022

出　　处：《表面技术》2024年第23期228-241,共14页Surface Technology

基　　金：吉林省自然科学基金(20240101088JC)。

摘　　要：目的研究不同振幅超声波辐射对激光熔覆Ni基WC涂层组织结构及力学性能的影响规律,为降低熔覆层残余应力,提高熔覆层力学性能,提升零部件服役寿命提供技术支持。方法在Cr12MoV模具钢表面激光熔覆Ni基WC涂层,将激光熔覆技术与超声波辐射技术相结合,以消除熔覆层中存在的裂纹和气孔等缺陷,提高成形工件的力学性能。首先,基于超声波在金属凝固过程中的空化效应和声流效应,结合晶粒生长规律,研究振幅参数对熔池和熔覆层宏观形貌、微观组织结构和物相组成的影响。其次,通过涂层硬度和耐磨性等对比试验分析超声辐射工艺对熔覆层力学性能的影响。最后,利用X-RAYS衍射仪测量熔覆层的纵向残余应力,探究超声辐射对熔覆层应力的影响,并解释超声波辐射增强熔覆层性能的作用机理。结果不同振幅超声辐射熔覆层的平均晶粒尺寸最大降低66.47%,显微组织主要由柱状晶和等轴晶组成,涂层物相主要是Ni-Cr-Fe和γ-(Fe,Ni)固溶体。磨损量分别降低了65.17%、95.74%、96.49%、76.67%、73.03%。熔覆层的平均显微硬度分别提高了14.86%、23.20%、28.10%、22.84%、16.76%,平均残余应力降低173.0 MPa,最大降幅点可达95.31%。结论超声波辐射有效降低了熔覆层残余应力和裂纹的产生,提高了熔覆层质量,进而增加零部件的使用寿命。随着超声波辐射振幅的提高,熔覆层表面粗糙度降低,显微硬度和耐磨性先提高、后降低,残余应力显著降低。综合判断,振幅为14μm的涂层晶粒细化程度最高,硬度和耐磨性最好。Based on the high processing efficiency and effective surface modification of laser cladding,ultrasonic radiation has been introduced to support the study of the effect of ultrasonic waves of different amplitudes on the microstructure and mechanical properties of laser cladding Ni-based WC coatings.The work aims to reduce the residual stress of the cladding coating,improve the mechanical properties of the cladding coating and improve the service life of parts to provide technical support.Ni-based WC coating was laser-melted on the surface of Cr12MoV die steel by combining laser cladding technology and ultrasonic radiation technology to eliminate the defects such as cracks and porosity existing in the cladding coating and improve the mechanical properties of molded parts.Firstly,based on the cavitation effect and acoustic flow effect produced by ultrasonic waves in the process of metal solidification,combined with the grain growth law,the effect of different amplitude parameters on the dispersion of WC inside the molten pool,the improvement of the macroscopic morphology of the molten cladding coating,the change of the microscopic structure and the composition of the physical phase was studied and a microscopic study was carried out on the optimization of the mechanical properties and the change of the residual stresses.Secondly,the effect of ultrasonic radiation process on the mechanical properties of Ni-based WC coating was analyzed through comparative experiments on the microhardness and wear resistance of each coating under different amplitude ultrasonic radiation-assisted processes.Finally,the longitudinal residual stress of the cladding coating was measured by X-RAYS diffractometer to investigate the change of the stress of the coating layer by ultrasonic radiation,and the role of ultrasonic radiation mechanism in enhancing the properties of the cladding coating was explained in conjunction with the change of the microstructure.The results showed that the average grain size of the ultrasonic radiation claddin

关 键 词：激光熔覆 超声波辐射 材料表征 残余应力 工艺参数 

分 类 号：TG456.7[金属学及工艺—焊接]