Experimental investigation of the anchoring effect of aluminum/amorphous-plastics joints fabricated by injection molded direct joining

Injection molded direct joining (IMDJ) is an efficient metal-plastic direct joining method. IMDJ injects melted plastic onto a pretreated metal surface and forms joints due to the plastic infiltration into surface structures. Unlike widely studied semicrystalline plastics, this study focused on the influence of injection parameters on the joining strength for two amorphous plastics. The anchoring effect was investigated by measuring the joining strength and the infiltration depth after joining. The results show that the interaction between packing pressure and injection speed obviously influenced the joining strength. Both high packing pressure and high injection speed were necessary for high joining strength. In addition, the results show that the joining strength positively correlated with the infiltration depth. Furthermore, a real-time plastic infiltration process was directly observed via mold visualization. A dynamic understanding of the infiltration was obtained. This paper contributes to a better understanding of the infiltration and the anchoring effect for amorphous plastics.