镀层金属在冲裁变形过程中流动规律的研究

IT制件冲裁断面的氧化现象会降低接触面的导电性,并最终导致零件的功能失效.本文建立了平面应变刚塑性有限元分析模型,对冲裁变形过程中镀层金属的变形和流动情况进行了数值模拟;提出冲裁后断面镀层金属分布的估算方法,并以常用的锡镀层锡磷青铜带为例,进行了实验验证.研究结果表明:冲裁变形过程中,镀层金属主要流入到冲裁断面的圆角带和光亮带上;采用基于数值模拟的断面镀层金属含量估算方法获得的断面光亮带上镀层金属含量和试验结果一致.本文所提出的方法可以用来在模具设计阶段评估不同冲裁工艺参数下冲裁断面的镀层金属含量,从而优选出断面镀层金属含量高的方案,从而达到提高断面抗氧化能力的目的.

Research on Flow Law of Coating Metal in Blanking Process

The oxidation on the blanking sections of IT products will weaken the contact conductibility and eventually lead to function failure of a product. A plane-strain rigid-plastic finite element analysis (FEA) model is established in this paper to simulate the deformation and flow of coating metal in the blanking process. A method to estimate the distribution of coating metal on blanking section is also presented and is verified by the experiments using tin-phosphorus-bronze band with Sn coating. The results show that the coating flows with substrate material and mainly scatters on the roll-over zone and the shearing zone of blanking section during blanking process; the estimated content of coating metal on blanking section fits well with the experiment results. The proposed method can be used to estimate the content of coating material using different blanking process parameters, and hence provide a way for optimizing these parameters to improve the oxidation resistance on the blanking sections.