航空用TC18钛合金的车削加工工艺技术研究

摘要

In this paper,the turning technology of a new kind of titanium alloy TC18 with ultra high strength is studied.First of all,the importance of accurate control of the surface roughness of turning parts is revealed by analyzing influence law of the machining surface roughness Ra on the fatigue life of TC18 titanium alloy.Then the orthogonal experiment is designed for turning parameters,and the surface roughness Ra value is used as the evaluation criterion of turning surface quality.At last,visual analysis,variance analysis,Taguchi method and multivariate linear regression analysis method are totally taken to analyze the results of turning test.The results show that the machined surface roughness has an important influence on fatigue life of TC18 titanium alloy,and the cutting feed f has the most significant effect on the machined surface roughness.A set of optimized parameters is obtained.It is established a quantitative correlation equation between spindle speed,cutting feed and depth with the surface roughness in the turning process of TC18 titanium alloy workpiece.Finally,the confirmation test proves that the obtained optimal parameters and the prediction equation of Ra are correct.%研究了难加工材料新型超高强度TC18钛合金的车削加工工艺技术。通过探讨机械加工表面粗糙度Ra对TC18钛合金疲劳寿命的影响规律,揭示了严格控制车削加工零部件表面粗糙度的重要性。利用正交试验法设计了车削加工工艺参数,以零件表面粗糙度Ra值为车削加工表面质量评价指标,采用直观分析法、方差分析法、Taguchi分析法以及多元线性回归分析法综合分析了车削加工试验结果。结果表明：机加工表面粗糙度对TC18合金疲劳寿命有重要的影响;车削加工走刀量f对TC18钛合金表面粗糙度影响最为显著。得到了一组优化的车削加工工艺参数,建立了预测车削加工TC18钛合金表面粗糙度与车削转速、走刀量和切削深度之间关系的定量方程,验证试验证明了其正确性。