定向内冷方法在高温合金铣削加工中的应用

Application of Directional Internal-cooling Method in Milling Process of Superalloy

针对浇注冷却铣削镍基高温合金时因供液不充分产生的过热问题,采用定向内冷方法改善铣削换热。采用计算流体动力学方法分析了定向内冷流场特性,结果表明:定向内冷可保证切削液准确集中喷射至切削区并改善换热。开展了浇注冷却、定向内冷的端铣试验,实验结果表明:在相同铣削参数下,定向内冷具有更好的换热性能,且随供液压力增加冷却效率增强,当压力为10 bar时,铣削温度、表面粗糙度和加工硬化分别降低32.2%、19.8%和11.9%,表面残余压应力增加105.52 MPa,获得了更规整的加工表面。

In view of the overheating problems caused by insufficient coolant of flood cooling in the milling process of nickel-based superalloy,the directional internal-cooling method was used to improve the milling heat transfer.The computational fluid dynamics method is used to analyze the flow field characteristics of directional internal cooling.The results show that cutting fluid can be injected into the cutting area accurately and centrally by directional internal-cooling method,and the heat transfer efficiency is improved.The end-milling experiments under flood cooling and directional internal-cooling were carried out.The experimental results indicate that under the same milling parameters,the directional internal cooling has better heat transfer performance,and the cooling efficiency increases with the increasing of coolant pressure.At a supply pressure of 10 bar,the milling temperature,the surface roughness and the degree of work-hardening decreased by 32.2%,19.8%and 11.9%,respectively,and the residual compressive stress in the surface increased by 105.52 MPa,and a more regular machined surface was obtained.