Experimental and Numerical aspects of B416 Cu-Be alloy friction stir process
Résumé
The Friction Stir Processing is an innovative surface engineering method, considered as a green processing technique. A good physical understanding of the process can be reached by the combined efforts of experimental examination and numerical modelling. In this study numerical and experimental investigations of Friction Stir Process (FSP) have been carried out on samples of B194 ASTM copper-beryllium alloy. The behavior of this alloy under FSP was studied using an experiment design at three levels of transversal speed (maximum speed 80 mm/min), three different normal forces (maximum force 1250 N) and two levels of rotational speed: 1000 and 2000 rpm. The treated layers have been characterized in terms of hardness and microstructure. The results obtained have shown that FSP in the tested range of parameters leads to the formation of a stirred layer with fine grains and high hardness (approximately 260% higher that the initial value of the base material). The friction between the tool and the work piece generates heat around the tool and produces microstructure modification by homogenization and refinement. These factors play a crucial role in heat generation during the process. The heat generating mechanism is influenced by the process parameters (normal load, rotational speed, transverse speed and geometric data). Thus the present study has been carried out in order to investigate the coupled effects of process parameters and the tool geometry on the thermal behavior of B194 ASTM copper-beryllium alloy under friction stir process. Numerical analyses in terms of heat generation and temperature distribution were carried out and a three-dimensional heat transfer model for friction stir process is proposed in this paper.
Domaines
Mécanique [physics]
Origine : Fichiers éditeurs autorisés sur une archive ouverte