Experimental analysis on mechanical interlocking of metal–polymer direct joining

• Published in: Precision engineering Vol. 61; pp. 120 - 125
• Main Authors: Zhao, Shuaijie, Kimura, Fuminobu, Kadoya, Shotaro, Kajihara, Yusuke
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.01.2020
• Subjects: Contact; Infiltration depth; Injection molded direct joining; Mechanical interlocking; Metal–polymer direct joining; Metal–polymer direct joining; Injection molded direct joining; Infiltration depth; Mechanical interlocking; Contact
• ISSN: 0141-6359; 1873-2372
• DOI: 10.1016/j.precisioneng.2019.10.009

Injection molded direct joining (IMDJ) is a method for direct joining of metals and polymers. In this work, we identified the most influential parameter for IMDJ and explained the reasons for successful joining by considering mechanical interlocking. We prepared hybrid joints of 30% glass-fiber-reinforced polybutylene terephthalate and aluminum alloy (A5052) plates with laser-treated surface dimples via IMDJ under various injection parameters. We studied the effects of the packing and holding pressures and the polymer temperatures on the joining strength. We discussed the reasons for the observed effects by considering mechanical interlocking, including the infiltration depth and the contact between the metal and the polymer. We found the packing pressure to be the most influential parameter. Moreover, the interaction between the packing pressure and the polymer temperature also influenced the joining strength considerably. The increased joining strength under various combinations of injection parameters was a result of deeper infiltration depth and better contact. We anticipate that the findings of this study will aid better selection of injection parameters for IMDJ. •The packing pressure was the most influential parameter for injection molded direct joining.•The interaction between the packing pressure and the polymer temperature also greatly affected the joining strength.•Packing pressure and polymer temperature affect infiltration and contact, whereas holding pressure affect only the contact.•The increased joining strength was a result of deeper infiltration depth and better contact.