基于检测结果的涡轮叶片精铸型腔反变形优化设计

针对空心涡轮叶片精铸过程中的试错法和数值仿真法难以敏捷反应铸件的真实变形情况,提出一种基于检测结果的精铸零件反变形综合补偿方法.通过对精铸叶片试模样件进行三坐标检测及统计分析,得到叶身截面收缩、扭转和弯曲变形情况,并建立其综合补偿反变形模具型腔优化算法,实现精铸型腔的反变形优化设计.以精铸叶片试模样件叶尖处截面为例,其叶身段型面误差、前缘最大误差、后缘最大误差相对于未补偿前分别减少了50%,68%和31%.实例验证表明:其研究成果能有效提高空心涡轮叶片的精铸成型精度,达到精确控形的目的. 

Optimization design of reverse deformation based on measuring results for investment cavity of turbine blade

As the trial and error method and the numerical simulation method have difficulty in accurately reflecting the deformation of the hollow turbine blade in the process of investment casting, a comprehensive compensation method of the reverse deformation based on the measuring result was prompted. Firstly, through inspection by three coordinates measuring machine (CMM) and statistical analysis of the investment blade sample, three kinds of deformation including shrinkage, torsion and bending of the blade body section were calculated, then a comprehensive compensation algorithm for the design of blade mold cavity based on the reverse deformation was established, in order to achieve optimization design of the investment cavity. Taking the tip section of the investment blade sample for example, the profile error of the blade body,the maximum error of leading edge,the maximum error of trailing edge decreased by 50%,68%,31%, compared with the uncompensated method. Finally the experiment results show that the method can effectively improve the forming precision, and precisely controll the shape of the hollow turbine blade.