Experimental Research On Mechanical Property Of AX31Plate、5052Plate And Magnesium-aluminum Composite Plate

Magnesium and its alloy cannot be used widely in many fields because of its poor corrosion resistance and poor abrasion resistance. By contrast, aluminum and its alloy have generally better corrosion resistance and better plasticity, specially its decoration function and better reparability. Therefore, a kind of roll-cladding plate with stripe construction is fabricated by rolling the aluminum alloy on the surface of magnesium alloy. This roll-cladding plate can protect magnesium alloy against corrosion, and also the advantages of high specific strength and specific stiffness of magnesium alloy can be taken fully. Magnalium roll-cladding plate is acknowledged by researchers at home and abroad, but the research is limited on the preparation and performance of magnalium roll-cladding plate, not covering the forming performance and stamping performance.This paper prepared magnesium-aluminum composite plate5052/AZ31/5052by hot rolling. The best rolling technological parameters were:the first rolling temperature was360℃, the rolling rating48.57%. the next three rolling temperature was380℃, the rolling rate22.22%、14.29%、16.67%, respectively. Cross rolling method was applied, aiming at improving the anisotropy of composite plate. After annealing treatment on magnesium-aluminum composite plate, the study showed that the boundary between strips can’t produce new phase at200℃, holding time1hour, then air cooling. Mmagnesium-aluminum composite plate had smaller grain size, uniform microstruction and the best combination property:elongation was up to23.9%, yield rate σs/σb had the lowest value,0.839.At room temperature, perform the uniaxial tension experiment on AZ31, hot rolling AZ31, annealing5052, magnesium-aluminum composite plate5052/AZ31/5052. Investigate the mechanical performance, such as yield strength, yield rating, elongation, strain hardening index n and plastic strain ratio r. This can provide the theory evidence and experimental datum for material stamping and industrial application. Based on these datum, this can better preparation of composite strips. Meanwhile, hot tensile experiment was done in order to get the information about the sensitive of magnesium-aluminum composite plate with temperature and provided the datum for next thermal forming.Also, fixtures were improved in the process of experiments, which makes experimental datum accurate and reliable.The research showed that the yield strength of Magnesium alloy AZ31was rapidly improved after cross rolling and annealing. Meanwhile, plasticity was quite improved, the anisotropy was lowered. The experiment showed that the strain hardening index n and plastic strain ratio r of AZ31before rolling are twice as much as that after rolling. The yield strength of magnesium-aluminum composite plate is lower than that of AZ31, but the elongation was improved. Strain hardening index n and plastic strain ratio r of magnesium-aluminum composite plate are both lower than those of AZ31, which shows that forming performance is slightly decreased. With comparison to tensile test at120℃, elongation is improved twice more than that at room temperature. However, strength decrease to the half value, combination performance decreases.