压铸模与铝铸件焊合区的特征及形成机理

模具焊合区的表面上，存在着一定数量的显微孔洞、显微凹陷及裂纹等表面缺陷，大大增加了模具与铸件间的真实接触面积，焊合区的截面主要由焊合的铝合金、过渡层、氮化层及钢基体组成。对模具与铸件不同的焊合模式及形成机理进行了分析，将焊合分为物理化学焊合、机械焊合和混合焊合，并分析了压铸生产中焊合的形成及扩展过程。

Characteristic and Formation Mechanism of Soldering Region between Die Casting Die and Aluminum Alloy Casting

On die surface of soldering region,there are a lot of surface defects such as microholes,microcaves and cracks,so as to increase the actual contact area between die and casting.The cross section of soldering region can be divided into four parts as soldered aluminum alloy,transition layer,nitriding layer and steel substrate.The mode and mechanism of soldering have been studied and the soldering is classified as physicochemical soldering,mechanical soldering and mixed soldering.The origination and propagation processes of die soldering during die casting production have also been analyzed.