清洁切削高温合金涂层刀具切削性能及加工表面完整性

针对高温合金高速干切削刀具磨损严重、加工表面质量差等突出问题，基于清洁切削技术，采用硬质合金涂层刀具进行高速铣削高温合金GH2132试验，研究干式切削、液氮不同喷射温度对涂层刀具切削性能以及加工表面完整性的影响规律，探究运用清洁切削高温合金来延长涂层刀具寿命和提高加工表面质量的可行性。研究表明：液氮低温切削GH2132时的切削合力随喷射温度的降低而增大，切削区温度在-150～-190℃喷射时已完全处于低温状态；随着液氮喷射温度的降低，刀具涂层剥落面积明显减小，且降低了黏结磨损和氧化磨损，在-150℃喷射条件下可获得较长的刀具寿命；加工表面粗糙度S_a在-30～-150℃喷射条件下获得较小值，随喷射温度的降低，加工硬化和残余拉应力分别增大和减小；与干式切削相比，液氮切削喷射温度在-150～-190℃下可显著延长涂层刀具寿命并提高加工表面质量。

Cutting Performance of Coated Tools and Machined Surface Integrity in Superalloy Clean Cutting

 In the high-speed dry cutting processes of superalloy， there were some prominent problems， such as serious tool wear， poor machining surface quality and so on. The experiments of high-speed milling of superalloy GH2132 were carried out with cemented carbide coated tools based on clean cutting technology. The effect laws of dry cutting and various injection temperatures of liquid nitrogen on the cutting performance of the coated tools and the integrity of the machined surface were studied， and the feasibility of using clean cutting superalloy to improve the life of the coated tools and the machined surface quality was investigated. The research shows that the cutting forces by liquid nitrogen cryogenic cutting GH2132 increase with the decrease of the injection temperature. The cutting temperature of the cutting zone completely reaches a low temperature condition when the injection temperature is as -150～-190 ℃. With the decrease of liquid nitrogen injection temperature， the peeling areas of the coating are obviously reduced， and the adhesive wear and oxidative wear are reduced. A longer tool life may be obtained under the injection condition of -150 ℃. The lower machined surface roughness Sa may be obtained under the injection condition of -30～-150 ℃. With the decrease of injection temperature， the work hardening and residual tensile stress are increased and decreased， respectively. Compared with the dry cutting， liquid nitrogen cutting injection temperature at -150～-190 ℃ may significantly improve the coated tool life and machined surface quality.