Study On The Relationship Between Adiabatie Shear Susceptivity And The Different Grain With Deformation Texture For AZ31Magnesium Alloy

Magnesium alloy has been playing a significant role in the fields of aerospace,automobile,military enterprise,electronic industry,and medical equipment, this is due to its great qualitiesof low density, rigidity and shock absorbtion, as well as its excellent insulativity, thermaldiffusivity and corrosion resistance. Therefore, there are more and more study about itsdynamic mechanical properties and failure behavior. Magnesium alloy’s structure of HCPlead to bad ability of.deformation mechanism,but its mechanical properties can improveafter microstructure of AZ31magnesium alloy was refined.As adiabatic shear band is a kindof special material failure,its appearance means a significant reduction in carrying capacityof materials and even complete loss, considered a sign of material failure.At present,there ishardly any study about aidabatic shear susceptivity of magnesium alloy,as the magnesiumalloy is applied more and more widely,so study on the relationship between adiabatic shearsusceptivity and the different grain and the different textural for AZ31magnesium alloy hasa very important theory of value and realistic significance.The aidabatic shear susceptivity was characterized by dynamic shearing experiment by usingthe technology of Split Hopkinson bar(SHPB).The adiabatic shear band of different grainand textural of AZ31magnesium alloy have been studied by opticalmicroscope(OM),scanning electron microscopy(SEM), transmission electron microscopy(TEM) and the microhardness.The results show that(1)The microstructure of AZ31magnesium alloy was refined bymeans of equal-channel angular pressing (ECAP), ECAPed four pass the grain of AZ31magnesium alloy is3~5μm.It is show that the smaller grain AZ31of magnesium alloy, theadiabatic shear susceptivity of AZ31magnesium alloy is weaker.The experimental resultsshow that macrocrack based on micro-void and microcrack in the adiabatic shear band andthe micro hardness of the microstructure in the core of the adiabatic shear band is higher thanthat of the microstructure around the adiabatic shear band.(2)For the two kinds of AZ31magnesium alloy’s textural, after using the technology ofSplit Hopkinson bar to do dynamic shearing experiment at room temperature and hightemperature.it shows that at room temperature there is no adiabatic shear band at AZ31 magnesium alloy,but at high temperature AZ31magnesium alloy with different textural bothappear the adiabatic shear band,so the deformation texture has no obvious influence to theadiabatic shear susceptivity.At the transitional region between adiabatic shear band andmetal base appears lots of elongated grain. The dynamic recrystallization takes place in theadiabatic shear bands and the adiabatic shear bands comprised of isometric crystal areformed. With the interactions of dislocations and twin crystals, transition regions betweenadiabatic shear bands and substrates are formed.