高速切削GH2132涂层刀具表面及次表面性能演变研究

Evolution of surface and subsurface properties of coated tools in high speedcutting of GH2132

  • 摘要: 高速切削过程中,涂层刀具表面性能及次表面残余应力的变化会直接影响刀具的切削性能。采用PVD-TiAlN硬质合金涂层刀具进行高速车削GH2132高温合金试验,研究刀具表面性能在切削过程中的变化规律,并用拉曼光谱法测量了刀具不同磨损阶段的涂层次表面残余应力分布。结果表明,刀具在完整寿命期间内,表面残余压应力和表面显微硬度均呈先增大后减小的趋势。刀具从未磨损到稳定磨损阶段中期,涂层截面残余应力均为残余压应力占主体且沿深度方向逐渐增大,但切削至稳定磨损阶段后期时,涂层在靠近基体位置出现残余压应力减小的现象。在稳定磨损阶段前期,刀具有最佳的表面性能及最大的次表面压应力,此时刀具切削性能最佳,刀具磨损缓慢。

     

    Abstract: During high-speed cutting, the changes in surface properties and subsurface stresses of coated cutting tools directly affect their cutting performance. High speed turning experiments were conducted on GH2132 high-temperature alloy using PVD-TiAlN hard alloy coated tools to study the changes in tool surface properties during the cutting process. Raman spectroscopy was used to measure the residual stress distribution on the sub surface of coated tools at different wear stages. The results show that during the complete service life of the cutting tool, the residual compressive stress and surface microhardness both show a trend of first increasing and then decreasing. The residual stress in the coating is mainly residual compressive stress, which gradually increases along the depth direction. However, when the wear reaches the later stage of stable wear, the residual compressive stress of the coating decreases near the substrate. During high-speed dry cutting, the tool has the best surface performance and the maximum residual compressive stress on the subsurface during the early stage of stable wear. At this time, the tool has the best cutting performance and slow tool wear.

     

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