Controlling Mechanical Properties of Warm Extruded Commercial V-65 Alloy

Abstract

V-65 (Russian grade) is commercial Aluminium alloy used in making rivets in aerospace applications as it exhibits relatively high shear strength and plasticity. Controlling properties of this alloy by the addition of second phase particles in the form Zirconium that hinders grain growth by exerting Zener drag is discussed in this work. The alloys were subjected to differential thermal analysis and peaks were observed at 4190c, indicating the dissolution of Al3Zr particles. The alloy was warm extruded at 300 & 3500c and the kinetics of Recrystallization was followed by image analysis on samples of recrystallized at 4200c for various times assuming that short duration of anneal would not dissolve Al3Zr because of diffusion coefficient of Zirconium in Aluminium is low. Detailed microstructure analysis indicated the Al3Zr particles exerted pinning pressure on grain boundaries effectively producing fine grains. These results were justified by the volume fraction analysis of grains. Transmission Electron Microscopy was also conducted and the fine particles were found to be Al3Zr particles with L1-2 crystal structure and lattice parameter 4.08 A0.The cube grains were identified by etch pit technique and it was found that addition of Zr did not alter the number of cube grains. These cube grains facilitate the alloy in deep drawing and its application in the fuselage of an aeroplane