Injection over-molding of polymer-metal hybrid joints

Abstract

Polymer-metal hybrid joints have been increasingly used in several industrial sectors since they are able to combine the mechanical strength of the metals with the ease of processing, design flexibility, lightness and durability of the polymers. In this context, the aim of this study is the development of polymer-metal hybrid joints produced by metal insert injection over-molding technique. This research study will be conducted by undergraduate and graduate students, under the guidance of the applicant, within the framework of an international collaboration with the Graz University of Technology (TUGraz), Austria. The joints shall consist of a combination of polycarbonate (PC) and AA6061 aluminum alloy for applications in the automotive industry, and bio-composite of high density polyethylene and hydroxyapatite (HDPE-HA) and Ti6Al4V titanium alloy for biomedical applications. The joints will be prepared in an automatic injection molding machine, varying the main processing parameters (temperature, pressure and time). The metal inserts will be surface treated to improve the interfacial strength of the joints. The static mechanical strength of the joints will be evaluated by lap-shear testing and the mechanical durability by dynamic fatigue. Some selected joints will be submitted to accelerated aging and then mechanically tested. Microstructural characterization of the polymer-metal interface will be carried out by optical (OM), scanning electron (SEM) and laser scanning confocal microscopy to identify the joining and failure mechanisms. The results will be analyzed to find correlations between processing conditions, microstructure and properties. The ultimate goal is production and diffusion of scientific and technological knowledge. (AU)