游动芯头拉拔模具失效分析

摘要

In order to decrease the abrasion of the plug in tube drawing with floating plug, the failure mecha- nism of the plug in different type were revealed. SEM, EDS and OM were used to analyze the different type fail- ure plugs and the material compositions. The results show that, due to lacking of the Co element or its relatively small bonding effects,the WC particles scratch the surface of the plug. Because of the compression stress in tube deformation course, the rising temperature and the poor lubrication, the circle gap is formed. The connect- ing of gas porosity in the copper tube and the rising roughness of the plug lead the copper adhere to the surface of the plug.%为了改善游动芯头拉拔过程中芯头模具的磨损,揭示芯头在拉拔过程中不同形式的失效机理.利用扫描电镜,金相显微镜对不同失效形式下模具进行观察及成分分析,同时对拉拔润滑油和铜管进行密度和黏度测量.结果表明：芯头模具表面局部Co元素的缺失或其黏合作用相对较小,导致WC颗粒在模具表面形成竖道划痕;芯头模具由于受到管材变形时压应力,在温升和润滑不良的情况下形成环形沟槽缺陷;管坯中的气孔在变形过程中贯穿连接,以及模具表面粗糙度的提升,导致管材上的铜粘附在模具表面.