Effects of Rotational Speed and Processing Time on Bonding Strength of Porous Aluminum and Thermoplastic Resin during Friction Welding

In this study, the bonding of porous aluminum (porous Al) and thermoplastic acrylic resin by friction welding was attempted. We investigated the relationship between bonding conditions (rotational speed of porous aluminum and processing time during friction welding) and the bonding strength during friction welding. This method enables us to obtain porous Al composite materials by bonding with anchor effects relatively easily in a short processing time. Therefore, it is expected to be applied to the fabrication of industrial products. Porous Al with a porosity of approximately 70% was fabricated by the spacer method, and then it was welded to an acrylic resin plate by friction welding. A tensile test was conducted on a bonded specimen to investigate the bonding strength. At a rotational speed of 680rpm, a specimen with the maximum bonding strength was obtained at the processing time of 60s. However, in case of longer processing time the bonding strength decreased with increasing processing time. At a rotational speed of 1100rpm, a specimen with the maximum bonding strength was obtained at the processing time of 40s, which the bonding strength decreased with increasing processing time. At a rotational speed of 2000 rpm, a specimen with the maximum bonding strength was obtained at the processing time of 20s, which the bonding strength decreased with increasing processing time. The decrease in bonding strength was considered to be caused by the generation of acrylic resin gas due to excessive frictional heat and a decrease in the thickness of the acrylic resin. It was concluded that porous Al and acrylic resin can be successfully bonded by friction welding. and that the higher the rotational speed, the shorter the processing time required for bonding.