EFFECT OF ROTARY SWAGING ON STRESS/STRAIN STATE WITHIN TUNGSTEN HEAVY ALLOY BAR

Abstract

Owing to their exceptional combination of mechanical and physical properties, tungsten heavy alloys (THAs) are advantageous for demanding applications. The presented study focuses on analysing the effects of processing of THA bar by the cold rotary swaging method, particularly on investigating the effects of processing on residual stress within the swaged bar. The stress-state was predicted numerically using the finite element method (FEM) and the results were subsequently validated using data acquired experimentally via scanning electron microscopy (SEM-EBSD). As shown by the results, the predicted parameters corresponded well with the experimentally acquired data; by the effect of the swaging process, the effective imposed strain was the highest at the surface of the bar and decreased towards its axis, which corresponded to the distribution of microhardness, as well as the detected residual stress distribution. Nevertheless, the study focused on preliminary swaging experiment consisting of two swaging passes; the predicted results impart that the stress/strain gradient will diminish with continuing swaging.