铜合金微塑性成形力学性能及其本构关系

对不同晶粒大小、不同特征尺寸的H62黄铜箔进行微拉伸实验,分析试样晶粒大小和特征尺寸对材料变形行为的影响.随着晶粒尺寸的减小,试样拉伸屈服应力逐渐增大,晶粒尺寸对屈服应力的影响满足Hall-Petch细晶强化关系;屈服强度随厚度的减小先减弱而后增强,随宽度的减小而增强;晶体塑性理论、表面层模型可以解释延伸率、抗拉强度随比表面积的增大而减小的现象.在实验数据的基础上通过修正双线性模型建立H62黄铜箔微塑性成形本构模型.

MECHANICAL PROPERTIES OF COPPER ALLOY DURING MICRO-PLASTIC FORMING AND ITS CONSTITUTIVE MODEL

Different grain sizes, different feature sizes of H62 brass foil was studied by micro tensile test, the effects of grain size and specimen size on the deformation behavior of material?characteristics was analyzed.With the decrease of the grain size, tensile yield stress increases, grain size effects on the yield stress satisfy Hall-Petch fine grain strengthening relations.Yield strength first decreases and then increase with the thickness decreases, and enhanced with the decrease of the width.Crystal plasticity theory, the surface layer model can the phenomenon of explain the elongation rate, tensile strength increases with the increase of specific surface area.Based on the experimental data of a micro plastic forming establishing micro-plasticity constitutive model by correcting bilinear models.