ANALYSIS OF THE FRICTION WELDING PROCESS IN RELATION TO THE WELDING OF COPPER AND STEEL BARS

The heat-transfer mechanism initiating the friction welding process is examined and a transient two-dimensional heat-conduction model for th e welding of two dissimilar cylindrical metal bars is introduced. The bar materials consist of copper and steel. To relate the theoretical p redictions with the resulting welds, experiments are conducted under d ifferent welding conditions by means of which metallurgical and microp robe analysis of the weld cross-sections are carried out. This provide s a visualization of the melted zones and of the diffusion depths. A s tatistical analysis is carried out for the affecting parameters on the mechanical properties of the resulting welds. The factors affecting t he weld include the speed of rotation, the weld duration (burn-off tim e), and the friction load, whilst the mechanical properties include th e tensile strength, the yield strength, the ultimate yield strength an d the micro hardness of the weld cross-sections. (C) 1998 Elsevier Sci ence S.A. All rights reserved.