钛合金薄壁曲面液态金属-磨粒流加工仿真与试验研究

Titanium Alloy Thin-walled Curved Surface Liquid Metal-abrasive Flow Machining Simulation and Experimental Research

针对钛合金薄壁曲面工件磨粒流抛光后表面粗糙度分布不均匀的问题,提出一种基于液态金属的磨粒流加工方法。基于SST k-ω模型、OKA冲蚀模型,流体流动颗粒追踪模型,采用COMSOL有限元软件对不同电场布置下的液态金属-磨粒流动力学特性开展深入研究。仿真结果表明,通过电场的合理布置可以控制液态金属颗粒在流场中运动;合理的电场布置可以有效提高工件表面加工均匀性,并通过仿真得出了一组冲蚀较好的试验参数。基于仿真结果开展了液态金属-磨粒流加工试验,试验结果表明:液态金属-磨粒流加工方法可有效提高工件表面加工的均匀性。在加工14h后,不加电场的磨粒流加工表面不同区域的粗糙度分布不均,工件凹陷处粗糙度明显大于凸起处,各区域表面粗糙度极差达到66.1 nm。使用液态金属-磨粒流加工后的工件表面各区域粗糙度的均匀性明显提高,各区域表面粗糙度极差减小为20.3 nm,为液态金属-磨粒流加工的开展及其调控提供了理论和试验依据。

Aiming at the uneven distribution of surface roughness of titanium alloy thin-walled curved workpieces after abrasive flow polishing,an abrasive flow machining method based on liquid metal is proposed.Based on the SST k-ωmodel,OKA erosion model,and fluid flow particle tracking model,COMSOL finite element software is used to conduct in-depth research on the dynamic characteristics of liquid metal-abrasive particles under different electric field arrangements.The simulation results show that the reasonable arrangement of the electric field can control the movement of liquid metal particles in the flow field and effectively improve the uniformity of the workpiece surface processing.Furthermore,a set of experimental parameters with better erosion are obtained through simulation.Based on the simulation results,a test platform is built and the liquid metal-abrasive flow machining experiments were performed.The experimental results show that the liquid metal-abrasive flow machining method can obviously improve the surface uniformity of the workpiece.After 14 hours of processing,the roughness distribution in different areas of the surface processed by abrasive flow without electric field is uneven.The roughness of the concave part of the workpiece is obviously greater than that of the convex part,and the surface roughness of each area reaches 66.1 nm.The uniformity of surface roughness in each region of the workpiece after liquid metal-abrasive flow machining is significantly improved,and the surface roughness range in each region is reduced to 20.3 nm,which provides theoretical and experimental basis for the development and regulation of liquid metal-abrasive flow machining.