Study On The Interface Behaviour For The Al/Mg Alloys Composite Mateirals Maded By Explosive Welding

Magnesium alloy with light weight, high strength and the advantage of richresources, has become the third-largest metal after iron and steel, aluminumengineering material. So far, although the magnesium alloy got some application,but relative to the numerous applications in metal materials, the application isnegligible. This is mainly because low toughness, and poor corrosion resistancefaults, seriously restrict the exertion of its advantages and the application. Inview of this point, magnesium/aluminum composite material maded by meansof explosive welding successfully.Through explosion welding method, using the optimized processparameters, the AZ31B magnesium alloy with AA6061aluminum alloycomposite. By means of OM, SEM, TEM and EDS and mechanical performancetest, systematically studied the explosion welding process and heat treatmentprocess on the interface evolution of organizational structure and the change ofmechanical properties, and further probes into the explosion welding interfacebonding mechanism of the composite material.AZ31B/AA6061explosive composite plates interface are wavy and closelyunifies in together, the elements of magnesium and aluminum in combinationshow a slight diffusion on the surface, so the composite plate leads to themetallurgical bonding. Near the combined interface generates fine equiaxedgrain, away from the elongation of grain serious deformation. Adiabatic shear band in magnesium alloy side, tissue within the centre for fine equiaxed grain, isinclined45°along the direction of explosion. In combination for the interface,the wave front and wave ridge has certain melting layer. TEM analysisconfirmed that the plastic deformation leads to present alarge amounts ofdislocation on the interface.Composite plates on interface area of the microhardness shows that thecomposite board combined with the interface has the highest microhardness,increase with the distance from combined interface, the microhardness of basematerials reduced gradually, finally tends to the hardness value on parent metal.The shear strength is105MPa.Composite plates after different heat treatment state, the interface elementsin different degree of diffusion, and with the increase of heat treatmenttemperature, the degree of interface element diffusion occur enhanced. And incombination with the interface to generate intermetallic compound. ForMg17Al12layer near the AZ31B side, near AA6061for Al3Mg2on one side of thelayer. The growth of intermetallic compounds in line with the parabolic law,based on this rule to establish the dynamics equation of the growth ofintermetallic compounds.Heat treatment after200C obviously improve the tensile properties of thecomposite plate, interface tensile strength is189MPa,300C and400C afterheat treatment, the appearance of the interfacial intermetallic layer make tensilestrength of composite board fell sharply. Composite plate bending resistance andthe interface fracture present different morphology under different heattreatment states.The causes of the formation for the interface wave for the plasticdeformation and the combination of jet. Combination of explosion welding zoneexists in the plastic deformation, melting and atoms diffusion characteristics is regarded as a combination of pressure welding, fusion welding, diffusionwelding.Through the study of explosion welding AZ31B/AA6061layeredcomposite material the behavior and the influence of heat treatment on theinterface, as to AZ31B/AA6061metal composite plate applied in productionpractice provide the oretical guidance and technical support.