深冷处理对Al_(2)O_(3)-SiC_(w)陶瓷刀具表面完整性及切削性能的影响

Effect of Cryogenic Treatment on Surface Integrity and Cutting Performance of Al_(2)O_(3)-SiC_(w)Ceramic Tools

陶瓷刀具高速切削高温合金时磨损严重,采用深冷处理技术可提升陶瓷刀具表面完整性,进而提高其高速切削过程中的耐磨性。基于深冷处理Al_(2)O_(3)-SiC_(w)陶瓷刀具和高速切削高温合金试验,研究了深冷处理工艺对陶瓷刀具表面完整性以及切削性能的影响规律。研究表明:一方面,陶瓷刀具经深冷处理后,表面的凹坑、沟痕、裂纹等缺陷明显减少,表面维氏硬度显著增大。与未处理刀具相比,陶瓷刀具表面残余压应力(绝对值)可提高70%。另一方面,刀具表面维氏硬度对切屑变形、切削力、刀具磨损的影响最大,表面维氏硬度的提高提升了刀具耐磨性。在-150℃、18 h的深冷处理条件下,陶瓷刀具可获得较高的切削性能。

The ceramic tool severely wears in the process of high-speed cutting of superalloy.By using cryogenic treatment technology,the surface integrity of the ceramic tool is improved.Moreover,the wear resistance is enhanced during high-speed cutting process.Based on the cryogenic treatment of ceramic tool of Al_(2)O_(3)-SiC_(w)and high-speed cutting superalloy experiments,the effect of cryogenic treatment on the surface integrity and cutting performance of ceramic tools were studied.The research shows that the defects such as pits,groove marks and cracks on the surface of the tool are significantly reduced after the ceramic tool is cryogenically treated.And the Vickers hardness of surface is significantly increased.Compared with untreated tool,the surface residual compressive stress(absolute value)of the ceramic tool can be significantly increased by 70%.On the other hand,the Vickers hardness of the surface of the tool has the greatest impact on chip deformation,cutting force,and tool wear.The improvement of the surface Vickers hardness enhances the wear resistance of the tool.The high cutting performance of the ceramic tool can be obtained at the conditions of cryogenic treatment at-150℃and 18 h.