Abstract The process of compaction of machining chips inside a cylindrical processing chamber is investigated. This process can be either an independent process or the first step in the Friction Extrusion Process (FEP) where the consolidated chips are softened due to frictional heating and are turned into a wire through an extrusion hole in the die. The current study provides an extension to our previous study in order to determine experimentally the Poisson's ratio as a function of the relative density during compaction. This determination is done through measurements of strains on the outer surface of the processing chamber containing the machining chips. The elastic theory of a thick-walled cylinder under internal pressure is employed to relate the surface strain measurements to stress and strain states at the processing chamber-chips interface. Also, the loading machine compliance effect is removed from the compaction and uniaxial test results whereas in the previous work it is implicitly assumed that the loading machine is rigid so that the measured axial deformation is taken to be entirely due to the deformation of the compacted chips. The porous elastic-plastic material model developed previously is extended to model the mechanical behavior of the chips during the compaction process. Simulation predictions of the axial stress-strain curves are performed and the predicted data are found to have a good agreement with experimental data.

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加工切屑的压实：扩展实验和建模

摘要 研究了圆柱形加工室内加工切屑的压实过程。这个过程可以是一个独立的过程，也可以是摩擦挤压工艺 (FEP) 的第一步，其中固结的切屑由于摩擦加热而软化，并通过模具中的挤压孔变成金属丝。当前的研究为我们之前的研究提供了扩展，以便通过实验确定泊松比作为压实过程中相对密度的函数。该确定是通过测量包含加工切屑的处理室的外表面上的应变来完成的。厚壁圆柱体在内部压力下的弹性理论被用来将表面应变测量与处理室-芯片界面处的应力和应变状态联系起来。此外，从压实和单轴测试结果中去除了加载机柔量效应，而在之前的工作中，隐含地假设加载机是刚性的，因此测量的轴向变形完全是由于压实切屑的变形造成的. 先前开发的多孔弹塑性材料模型被扩展为模拟压实过程中切屑的机械行为。对轴向应力-应变曲线进行了模拟预测，发现预测数据与实验数据具有良好的一致性。从压实和单轴测试结果中去除了加载机柔量效应，而在之前的工作中，隐含地假设加载机是刚性的，因此测量的轴向变形完全是由于压实切屑的变形造成的。先前开发的多孔弹塑性材料模型被扩展为模拟压实过程中切屑的机械行为。对轴向应力-应变曲线进行了模拟预测，发现预测数据与实验数据具有良好的一致性。从压实和单轴测试结果中去除了加载机柔量效应，而在之前的工作中，隐含地假设加载机是刚性的，因此测量的轴向变形完全是由于压实切屑的变形造成的。先前开发的多孔弹塑性材料模型被扩展为模拟压实过程中切屑的机械行为。对轴向应力-应变曲线进行了模拟预测，发现预测数据与实验数据具有良好的一致性。先前开发的多孔弹塑性材料模型被扩展为模拟压实过程中切屑的机械行为。对轴向应力-应变曲线进行了模拟预测，发现预测数据与实验数据具有良好的一致性。先前开发的多孔弹塑性材料模型被扩展为模拟压实过程中切屑的机械行为。对轴向应力-应变曲线进行了模拟预测，发现预测数据与实验数据具有良好的一致性。