工艺参数对TC4合金航空发动机叶片精锻残余应力的影响

为获悉叶片精锻残余应力的分布情况,利用Simufact. Forming软件对TC4合金航空发动机叶片精锻过程进行了数值模拟研究。通过X射线衍射技术对叶片实体表层残余应力进行了测量,并与数值模拟结果进行对比,验证了有限元模型的合理性。通过设计正交试验优化了叶片精锻工艺,最终得到了最优工艺参数组合及不同工艺参数对叶片精锻残余应力的影响趋势。研究结果表明:航空发动机精锻叶片的残余应力主要集中在表层,当工艺性较差时,叶片前缘头、后缘头附近的高残余应力区域范围较大,开裂的风险系数较高;模具温度对叶片精锻残余应力的影响最大,上模速度、坯料温度、摩擦因子对其影响依次减小;在上模速度为40 mm·s-1、坯料温度为960℃、模具温度为300℃、摩擦因子为0. 1的情况下,可以得到较小的叶片精锻残余应力。

Influence of process parameters on residual stress for TC4 alloy aero-engine blade in precision forging

In order to obtain the distribution of residual stress in the precision forging of blade,the precision forging process of TC4 alloy aero-engine blade was simulated numerically by software Simufact. Forming,and the residual stress on the surface of blade entity was measured by X-ray diffraction technique. Then,the numerical simulation results were compared to verify the rationality of the finite element model,and the precision forging process of blade was optimized by designing orthogonal experiment. Finally,the optimal combination of process parameters and the influence trend of different process parameters on the residual stress of blade in precision forging were obtained. The results show that the residual stress of aero-engine blade in precision forging is mainly concentrated on the surface layer.When the process is poor,the areas of high residual stress near the leading edge and the trailing edge of blade are larger,and the risk factor of cracking is higher. Furthermore,the mold temperature has the greatest influence on the residual stress of blade in precision forging,and the influences of upper mold speed,billet temperature and friction factor on the residual stress decrease successively. Thus,the smaller residual stress of blade in precision forging is obtained with the upper mold speed of 40 mm·s-1,the billet temperature of960 ℃,the mold temperature of 300 ℃ and the friction factor of 0. 1.