To improve the bond strength of hybrid components when joined by friction welding, specimens with various front end surface geometries were evaluated. Rods made of aluminum AA6082 (AlSi1MgMn/EN AW-6082) and the case-hardening steel 20MnCr5 (AISI 5120) with adapted joining surface geometries were investigated to create both a form-locked and material-bonded joint. Eight different geometries were selected and tested. Subsequently, the joined components were metallographically examined to analyze the bonding and the resulting microstructures. The mechanical properties were tested by means of tensile tests and hardness measurements. Three geometrical variants with different locking types were identified as the most promising for further processing in a forming process chain due to the observed material bond and tensile strengths above 220 MPa. The hardness tests revealed an increase in the steel’s hardness and a softening of the aluminum near the transition area. Apparent intermetallic phases in the joining zone were analyzed by scanning electron microscopy (SEM) and an accumulation of silicon in the joining zone was detected by energy-dispersive X-ray spectroscopy (EDS).

中文翻译：

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摩擦焊接半成品的接触几何形状修改，以改善混合组件的粘合

为了提高混合组件通过摩擦焊接连接时的粘结强度，对具有各种前端表面几何形状的样品进行了评估。研究了由铝AA6082（AlSi1MgMn / EN AW-6082）和表面硬化钢20MnCr5（AISI 5120）制成的具有合适的连接表面几何形状的杆，以创建形状锁合和材料粘合的接头。选择并测试了八种不同的几何形状。随后，对接合的部件进行金相检查，以分析结合和所得的微结构。通过拉伸测试和硬度测量来测试机械性能。由于观察到的材料粘结和超过220 MPa的拉伸强度，具有不同锁定类型的三种几何变形被确定为最有希望在成形工艺链中进行进一步加工的。硬度测试表明，钢的硬度增加，过渡区域附近的铝软化。通过扫描电子显微镜（SEM）分析了接合区中的表观金属间相，并且通过能量色散X射线光谱法（EDS）检测了接合区中硅的积累。