Environmentally friendly welding technologies for advanced materials

Abstract

Environmentally friendly welding methods applied in the welding of advanced materials are reviewed in this article. Friction welding, diffusion welding and vacuum soldering are discussed. The possibility of friction welding's application in the case of metals and elastic materials (e.g. Al₂O₃), is presented on the basis of an analysis of the existing literature, as well as the author's and his doctoral students’ own papers. Non-uniform distribution of pressure, deformations and temperature upon welded surfaces during the welding process is discovered. The influence of Al diffusion into Al₂O₃ on the state of proper stresses in a joint is determined. The diffusion coefficient of Al into Al₂O₃ is estimated at a level of 1.8 × 10 ^− 13 ms^− 1, and the size of stresses caused by diffusion is from 0.2 to 0.8 MPa. The intermetallic Fe–Al type alloys welded with construction steel with diffusion methods are characterized by high tensile strength from 304 to 362 MPa. An exemplary utilization of the discussed welding methods is presented in the case of rollers operating in fluid-flow machines. The discussed welding methods can be used not only in laboratory and research work, but also under industrial conditions.