在其他条件一定的情况下 ,采用二次旋转正交组合试验设计方法 ,以活化电流密度、活化时间为因素开展试验 ,探索球墨铸铁、45钢及 40 Cr最佳活化规范。通过研究分析了活化电流密度及活化时间对结合强度的影响规律 ,指出 3种材质最佳活化规范差异 ,并在金相、电镜试验基础上分析了活化机理 Under other conditions, the quadratic rotation orthogonal test design method was used to test the activation current density and activation time. The optimum activation rules of ductile iron, 45 steel and 40 Cr were explored. The influences of activation current density and activation time on the bonding strength were analyzed and analyzed. The differences of the optimum activation criteria for the three materials were pointed out. The activation mechanism was also analyzed on the basis of metallographic and electron microscope tests