摘要
进一步改善涂层组织性能,采用新型表面微晶化技术——高温辅助超声深滚(HT+UDR)对金属陶瓷涂层进行处理,通过高温处理使金属陶瓷涂层软化,可降低涂层强度与硬度,在超声深滚过程中涂层表面发生较大塑性变形。为此,采用SEM、EDS、硬度测试和XRD测试等考察了高温辅助超声深滚不同下压量(0.20,0.25,0.30 mm)对45钢基体表面陶瓷涂层组织、结构和性能的影响。结果表明:HT+UDR+0.25 mm处理后涂层内部纵向裂纹在塑性流变作用下弥合或转变为横向裂纹,孔隙率较小。表面产生加工硬化和晶粒细化后,硬度进一步提高至650.2 HV。涂层表面残余拉应力转变为残余压应力,最大为-337.9 MPa。但HT+UDR+0.30 mm处理涂层表层出现裂纹,表面动态再结晶行为加剧,位错密度下降导致残余应力释放,相对于HT+UDR+0.25 mm降低了8.67%。
In order to further improve the coating microstructure and properties,a new surface micro-crystallization technique,high temperature assisted ultrasonic deep rolling(HT+UDR),was used to treat the cermet coating,which could soften the cermet coating by high temperature treatment,thus reducing the strength and hardness of the coating,and large plastic deformation would occur on the coating surface during ultrasonic deep rolling.In this paper,SEM,EDS,hardness test and XRD were used to investigate the effect of different pressing amounts(0.20 mm,0.25 mm,0.30 mm)in high temperature assisted ultrasonic deep rolling on the microstructure,structure and properties of ceramic coating on 45 steel substrate.Results showed that after HT+UDR+0.25 mm treatment,the longitudinal cracks in the coating were closed or transformed into transverse cracks under the action of plastic flow,and the porosity was small.After work hardening and grain refinement,the surface hardness was further increased to 650.2 HV.The residual tensile stress on the coating surface was changed into residual compressive stress,with the maximum value of-337.9 Mpa.However,cracks appeared on the surface layer of the coating after HT+UDR+0.30 mm treatment,and the dynamic recrystallization behavior of the surface was intensified.The decrease of dislocation density led to the release of residual stress,which was 8.67%lower than that of HT+UDR+0.25 mm treatment.
作者
张峻
赵运才
何扬
张新宇
孟成
ZHANG Jun;ZHAO Yun-cai;HE Yang;ZHANG Xin-yu;MENG Cheng(School of Mechanical and Electrical Engineering,Jiangxi University of Science and Technology,Ganzhou 341000,China)
出处
《材料保护》
CAS
CSCD
2022年第12期100-105,131,共7页
Materials Protection
基金
国家自然科学基金项目(51965023)资助。
关键词
高温辅助
超声深滚
下压量
金属陶瓷涂层
high-temperature assisted
ultrasonic deep rolling
pressing amount
cermet coating
