微切削加工中材料微观结构效应的有限元分析

摘要/Abstract

摘要：

为了研究材料微观组织结构对微切削加工中尺寸效应的影响,建立了一种基于材料微结构特征的正交切削有限元模型,工件采用非均质材料模型。仿真结果表明：当材料微观组织结构一定时,不同的加工尺度下产生不同的切屑形态;当切削厚度从上百微米下降到几个微米时,切屑由连续状向准静态挤压状转换,切削厚度越接近最小金相颗粒的尺寸,挤压状切屑越明显;在应力分布图上可看出,加工中最大的应力不仅出现在刀刃周围,还出现在异相颗粒之间的晶界处,说明多相材料在微尺度加工下微观结构效应显著。

关键词:

微切削, 材料微观结构效应, 尺寸效应, 有限元模型

Abstract:

In order to investigate the influences of material microstructure on the size effect in micro cutting,a microstructure-level simulation model was developed to characterize machining behavior of heterogeneous materials. The results show that, for a given material microstructure, the chip morphology changes as the uncut chip thickness changes. When the uncut chip thickness is decreased from hundred microns to few microns, the chip formation changes from continuous to a quasi-shear-extrusion, and the uncut chip thickness is more close to the size of the smallest grain, the extrusion is more obviously; in the stress diagram, the maximum stress appears around the tool edge and the grain boundary.It illustrates that the material microstructure effect is prominence during micro cutting processes.

Key words: micro-cutting, material microstructure effect, size effect, finite element model

中图分类号:

TG501

庞迎春, 李迎.

微切削加工中材料微观结构效应的有限元分析

[J]. 中国机械工程, 2011, 22(19): 2369-2374.

LONG Ying-Chun, LI Ying.

Finite Element Analysis of Material Microstructure Effect in Micro-cutting Processes

[J]. China Mechanical Engineering, 2011, 22(19): 2369-2374.

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