摘要: |
加工表面完整性对材料的服役性能有着重要的作用。使用陶瓷刀具,对高温合金GH4169进行车削加工,分析不同车削速度对表面完整性各特征参量的影响,采用光学显微镜、扫描电子显微镜、显微硬度仪和XRD等仪器对表面微观结构、显微硬度和残余应力进行观测。结果表明:表面粗糙度随切削速度的增大而减小;加工表层存在滑移,且有明显的加工硬化现象,表层显微硬度随着车削速度的增大呈现增大趋势;轴向表面残余应力均为拉应力,且随着车削速度的增大拉应力先增大后减小,原因在于当速度增大至一定程度时,热量短时间内无法传递到工件内部,导致热效应的作用效果减弱。 |
关键词: 表面完整性 车削加工 残余应力 显微硬度 |
DOI:10.11933/j.issn.1007-9289.2015.03.017 |
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Effects of Cutting Speed on Machining Surface Integrity of GH4169 |
JIN Jieru, ZHANG Xiancheng, TU Shantung, YE Youjun1,2
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1. Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237;2. Special Equipment Safety Supervision Inspection Institute of Jiangsu Province, Nanjing 200000
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Abstract: |
Surface integrity is an important factor that can impact the service performance of the material. In this paper, the turning of GH4169 was conducted with the ceramic cutting tool at different cutting speeds in detail. The effect of cutting speed on the surface integrity was investigated in detail. The optical microscope, scanning electron microscope, hardness tester and Xray diffraction (XRD) were used to observe the microstructure near the surface and measure the microhardness and the residual stress. The results show that the surface roughness decreases with the cutting speed increase. Slipping and obvious work hardening exist near the machined surface. The microhardness at the machined surface increases with the cutting speed increase. The tensile residual stress generates at the machined surface increases in the axial direction, reaches a local maximum, and then decreases with the cutting speed increase. This phenomenon is due to the fact that the time for the thermal transmission through the machined surface decreases when the cutting speed increases to some degree. |
Key words: surface integrity turning residual stress microhardness |