Effect Of AZ80 Magnesium Alloy Twins During Plastic Deformation In Heat Treatment

As the lightest structural materials, Magnesium alloy with its rich resources gradually is attracted people’s attention. But special crystal structure of magnesium alloy HCP is largely restricted to the capacity of plastic deformation at room temperature. Research on AZ80 magnesium alloy during plastic deformation twinning behaviour in different heat treatment conditions plays a positive significance for improving plasticity at room temperature and promoting the wide application of magnesium alloy products.This topic will be based on the past research as the theory, first exploring the influence of deformation on microstructure and properties of AZ80 magnesium alloy, then discussing the influence of different heat treatment caused by the second phase precipitation method process on plastic deformation behavior of the twin. The research contents are as follows:(1)The deformation temperature, deformation, strain rate will have an impact on the process of plastic deformation in twin behavior, thus affecting the mechanical properties of the alloy. Deformation temperature affect the properties of alloy though the impact of critical shear stress needed on the non basal slip starting; the twin boundary density firstly increases and then decreases as the deformation increases, which is the twin coalescence results; The higher strain rate is, the more obvious.(2)There is a strong initial(0001) basal texture in alloy, and tensile process is help to the formation of tensile twins 2}1{10. 2}1{10 tension twinning is the main type of deformation twins in the process, due to the orientation transformation of large angle started by the tension twinning, center texture gradually became weakened, and edge texture enhanced.(3)With different soaking time, there are great differences between microstructure and properties. Comprehensively thinking the experimental results, the optimum solution scheme: 5h water cooling after solid solution treatment(4)The precipitation method of second phase is different,the properties of the alloy are also different. The different aging temperatures effect the distribution of the second phase and plastic deformation mechanism. At higher temperatures, the second phase is mainly the continuous precipitation, distribute in dispersed way with less Twin assist function; at lower aging temperature, generally the discontinuous precipitation will occur, the second phase distribute along the grain boundary. That will easily cause the stress concentration, making the tendency of twinning increases.