Effects Of Rare Earth Y And Gd On The Microstructure And Properties Of AZ31Magnesium Alloy

In this paper, based on experiments.Choosing AZ31magnesium alloy as the research object, the compound of rare earth (Y+Gd) as alloy elements was added, researching the organization and performance of rare earth magnesium alloy AZ31-x%RE. During the experiment, analysising the composition and phase composition of alloy with OM, XRD and other means. In the Gleeble-1500D simulator for hot compression experiment.The flow stress-strain curves and microstructure of AZ31-x%RE alloys were analyzed; Through electrochemical test methods research AZ31-x%RE (x=1.5,2.2,1.5) corrosion performance. I have studied the organization of the different content of RE AZ31, mechanical properties, corrosion resistance and the influence of deformation behavior systematically. The results show that:Adding rare earth Y, Gd element to the AZ31magnesium alloy, the grain boundary mesh to reduce the number of β-Mg17Al12to disappear, a new phase Al2Gd, Al2Y, and a small amount of Mg12RE appear in the organization. With the increase of RE content, organization of the precipitated phase increase in the number and size gradually decreases, and the alloy as-cast matrix was obviously thinning. Magnesium alloy by rapid water cooling.a new organization with more and more number of small grains has been further refined. The new phase have been more small and more further refine grain. Especially when RE content reaches3%,the organization of the grain size by water-cooled121um reduced to61.4um, decreased the rate of49.25%.When AZ31-x%RE magnesium alloy during hot compression, the influence of deformation temperature and RE content on the stress is obvious, flow stress decreases with the increase of deformation temperature, the peak stress appears relatively early. Corresponding tissue more evenly as the temperature increases, the grain size increases. As to add the increase of RE content, the deformation resistance alloy is more and more bigger, the curve of the peak stress is becoming more and more bigger. RE have refinedt thermal compression organization obvious also.Y, Gd can refine the alloy microstructure AZ31magnesium of rolling state and improve the mechanical properties of rolling state. When the rare earth content of3.0%, the magnesium alloy grain minimum size of rolling state to4.425um. Tensile strength and elongation are reached the maximum tensile strength of205Mpa, an elongation of7.25%.In the volume fraction of3.5%neutral NaCl solution we have studied AZ31-x%RE (x=1.5,2.2,3.0) alloy’s corrosion behavior by electrochemical method. The results showed that:In the range of testing rare earth alloys, the biggest capacitive reactance arc is the rare earth content of2.3, and with time, the surface have formed a protective film to enhancecorrosion resistance. Polarization curve test also showed that the rare earth content is2.3%of the magnesium alloy has the highest corrosion potential, corrosion current density of the minimum, the best corrosion resistance...