倒棱切削刃对6061铝合金大应变挤出切削仿真影响研究

Research on Influence of Chamfering Cutting Edge on Simulation of 6061 Aluminum Alloy Large Strain Extrusion Machining Process

大应变挤出切削(LSEM)是制备超细晶材料的一种大塑性变形法。为探究刀具切削刃结构对LSEM制备6061铝合金切屑带材的影响,选用具备倒棱切削刃的主刀具建立有限元模型,并进行模拟仿真,分析了倒棱负前角和棱边宽度对等效应变、等效应变率和切削力等热力学参数的影响。结果表明:主刀具切削刃为倒棱结构时,可获得较大的等效应变,最大等效应变值可达6.63;当倒棱结构参数变化时,等效应变、等效应变率、等效应力和温度图均呈带状分布;当倒棱负前角(绝对值)和棱边宽度增大时,最大等效应变、最大等效应变率和平均进给抗力也增大,且变化相对较明显,而最大等效应力和最高温度变化很小,几乎可以忽略不计。

Large strain extrusion machining(LSEM) is a severe plastic deformation method for preparing ultra-fine-grained materials. In order to explore the influence of tool cutting edge structure on LSEM 6061 aluminum alloy chip strip, the main tool of chamfering cutting edge is selected, the finite element simulation model is established, and the simulation is performed. The impact of the chamfer′s negative rake angle and edge width on the thermo dynamic parameters such as effective strain, effective strain rate and cutting force is analyzed.The results show that when the main tool′s cutting edge has a chamfered structure, a more considerable effective strain can be obtained, and the maximum effective strain value can reach 6.63.When the chamfer structure parameters change, the effective strain, the effective strain rate, the effective stress and temperature maps are distributed in a strip.When the negative rake angle(absolute value) of the chamfer and the edge width increase, the maximum effective strain, the maximum effective strain rate and the average feed resistance also increases, and the change is relatively apparent, while the maximum effective stress and maximum temperature change are very small, almost negligible.