Abstract:

In order to improve the consistency of a complex-shaped
surface by AFM,a method of processing the complex-shaped surface uniformly was
put forward.In the processing of the complex-shaped surface,the uniformity of the shear force distribution was improved and the consistency of
the surface roughness was enhanced by setting up a mold core.At first,according to the properties of  the abrasive medium and the relational algebra between the shear rate and viscosity,a power law model was established.Then,the distribution of the velocities,shear rate and shear forces of the abrasive flow on the surface was obtained by CFD module of the COMSOL Multiphysics software.The simulation results show that the relatively uniform runner is formed and shear stress on every part of the abnormity bent surface is more uniform
when the similar shape of the mold core is inserted into the complex hole.The experimental results demonstrate that the surface roughness Ra is reduced from 0.376μm to 0.017μm through adopting the mold core.

Key words: abrasive flow machining(AFM), complex-shaped surface, mold core, consistency

摘要：

针对磨料流加工异形曲面一致性较差的问题,提出通过设置相似模芯结构以改善剪切应力分布的状态,从而实现均匀化加工异形曲面的方法。根据磨料流的剪切率与黏度的关系建立了幂律模型,通过COMSOL Multiphysics软件的
CFD模块计算得到置入模芯时磨料介质在加工表面的速度、剪切率和剪切应力的分布。仿真与实验表明:置入相似的模芯后可形成等宽的流道,各曲面受到的剪切应力趋向一致。工件内壁表面粗糙度Ra最大差值由无模芯时的0.376μm降为置入模芯后的0.017μm。

关键词: 磨料流加工, 异形曲面, 模芯, 一致性