超细硬质合金磨削表面残余应力的实验研究

摘要

磨削表面残余应力对超细硬质合金刀具的使用性能有重要影响。为优化磨削工艺,作者在使用金刚石砂轮的平面磨床上进行了超细晶粒WC-Co硬质合金的磨削实验,通过用X射线衍射法测定磨削加工表面的残余应力,研究了砂轮粒度和切削深度对超细硬质合金磨削表面残余应力的影响。结果表明,超细硬质合金磨削表面的残余应力主要是磨削残余应力。实验条件下,超细硬质合金磨削表面的残余应力为压应力,其数值随砂轮粒径的减小而降低,切削深度对残余应力影响较小。%Residual stress in the ground surface layer has a great influence on the performance of ultrafine carbides tools.To optimize the grinding process,this study conducted surface grinding on ultrafine-grained WC-Co hardmetals by diamond wheel under various grinding conditions.Residual surface stresses were measured after grinding by mean of X-ray diffraction equipment.The study investigated the residual surface stress in the grinding of ultrafine-grained WC-Co hardmetals.The results show that the residual surface stress of ground ultrafine cemented carbides depends strongly on the grinding instead of the sintering residual stress.Grinding will cause the residual compressive stress in the surface layer of ground cemented carbides under various grinding conditions;the magnitude of residual surface stress will increase with increased grit size of diamond wheel,and will not be changed obviously along with the changing of depth of cut.