Abstract
In this work the feasibility of friction spot welding of thermoplastics was investigated on poly (methyl methacrylate) plates. Preliminary results have shown that the weld strength is comparable to other available welding techniques, while joining times are equal or shorter. Light optical microscopy and Vickers microhardness measurements showed the presence of a heat affected zone and a thin, consolidated stir zone, where physical–chemical transformations related to thermo-mechanical processing led to changes in local mechanical strength. The work has demonstrated for the first time that the welding of thermoplastic materials by friction spot welding is feasible.