HOT DEFORMATION BEHAVIOUR OF Mg-Zn -Gd-Nd ALLOY

Abstract

Today world needs light and high strength material as a structural material for better efficiency and high fuel efficiency application. Magnesium based alloy are an emerging light material for the same. Magnesium has attracted in the automobile industry and aerospace industry. Magnesium has improved the performance and fuel efficiency of the vehicle and aeroplanes. Light weight along with the strength has generated interest in it. However, the poor ductility and formability at low temperature, particularly at room temperature has limited the application of magnesium. People are using as cast structure until now but the use of wrought magnesium is very less due to the limited formability. This limited formability is due to limited slip system and strong unfavourable texture formation during deformation. In order to weaken this texture small rare earth element addition has been done. Due to rare earth addition room temperature formability can be optimised. In the present study hot deformation of the Mg-Gd-Nd-Zn alloy has been carried out and the alloy has been experimentally examined and study the effect of rare earth addition on mechanical property and its texture. The as cast Mg alloy with composition (Nd+Gd mixture 0.8-1.7 wt %), zinc (3.5-5 wt %), zirconium (0.4-1 wt %), and traces amount Mn, Fe, Cu, Ni, Si had given homogenisation heat treatment. The homogenised alloy was forged multiaxially and then compression tests of forged sample were performed. XRD analysis were done to identify the phase that are present in the alloy. Microstructure were examined using optical microscope and the Scanning Electron Microscope. Texture measurement were done using XRD and the inverse pole figure were plotted. Effect on mechanical properties were evaluated by plotting compression stress-strain curve and by analysing it. Effect on strain hardening parameter were studied by plotting hardening parameter vs. temperature inverse graph