Abstract Highly finished copper surface without any appreciable residual stress is in high demand in electronics, space, and optical industries. Conventional finishing processes are not suitable for the finishing of copper owing to its extremely lower hardness. In the present study, wheel based magnetorheological finishing (MRF) process is used to attain nanolevel surface roughness of oxygen-free high conductivity (OFHC) copper. The wheel speed, working gap and feed rate are selected as the main controlling process parameters. Areal surface roughness ( S a ), normal force, tangential force and residual stress are studied as the response parameters. The measurement of residual stress has a significant importance as it may affect the optical properties of the finished surface. The residual stresses and phases of all the finished surfaces are analysed using X-ray diffraction (XRD) technique. A theoretical model is proposed to predict the surface roughness of the MRF processed surfaces. It is observed that a nanolevel surface roughness with lower residual stress can be attained by performing MRF with a higher working gap, and lower wheel speed and feed rate. In the present study, a minimum surface roughness ( S a ) of 15.5 nm and compressive residual stress of 6.9 MPa are attained on the OFHC copper surface.

中文翻译：

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OFHC铜磁流变精加工表面粗糙度和残余应力的实验和理论研究

摘要 在电子、航天和光学行业中，对没有任何明显残余应力的高度精加工的铜表面有很高的需求。由于铜的硬度极低，传统的精加工工艺不适用于铜的精加工。在本研究中，基于轮的磁流变精加工 (MRF) 工艺用于获得无氧高电导率 (OFHC) 铜的纳米级表面粗糙度。选择砂轮速度、工作间隙和进给速度作为主要控制工艺参数。表面粗糙度（ S a ）、法向力、切向力和残余应力作为响应参数进行研究。残余应力的测量具有重要意义，因为它可能会影响成品表面的光学性能。使用 X 射线衍射 (XRD) 技术分析所有成品表面的残余应力和相。提出了一种理论模型来预测 MRF 加工表面的表面粗糙度。据观察，通过以更高的工作间隙、更低的轮速和进给率执行 MRF，可以获得具有更低残余应力的纳米级表面粗糙度。在本研究中，OFHC 铜表面的最小表面粗糙度 (S a ) 为 15.5 nm，残余压应力为 6.9 MPa。