The influence of cryorolling(CR),room temperature rolling(RTR)and post annealing on precipitation,microstructuralevolution(recovery,recrystallisation and grain growth),mechanical and corrosion behavior,was investigate...The influence of cryorolling(CR),room temperature rolling(RTR)and post annealing on precipitation,microstructuralevolution(recovery,recrystallisation and grain growth),mechanical and corrosion behavior,was investigated in the present work.The precipitation kinetics and microstructural morphology of CR,RTR,and post annealed samples were investigated by differentialscanning calorimetry(DSC),transmission electron microscopy(TEM),and electron back scattered diffraction(EBSD)to elucidatethe observed mechanical properties.After annealing at200°C,UTS and hardness of CR samples(345MPa and HV127)wereimproved as compared to RTR samples(320MPa and HV115).The increase in hardness and UTS of CR samples after annealing at200°C was due to precipitation ofβ''from Al matrix,which imparted higher Zener drag effect as compared to RTR samples.Theimprovement in corrosion and pitting potentials was observed for CR samples(?1.321V and?700mV)as compared to RTRsamples(?1.335V and?710mV).In CR samples,heavy dislocation density and dissolution of Mg4Al3Si4-precipitates in the Almatrix have improved corrosion resistance of the alloy through formation of protective passive layer and suppression of galvanic cell,respectively.展开更多
文摘The influence of cryorolling(CR),room temperature rolling(RTR)and post annealing on precipitation,microstructuralevolution(recovery,recrystallisation and grain growth),mechanical and corrosion behavior,was investigated in the present work.The precipitation kinetics and microstructural morphology of CR,RTR,and post annealed samples were investigated by differentialscanning calorimetry(DSC),transmission electron microscopy(TEM),and electron back scattered diffraction(EBSD)to elucidatethe observed mechanical properties.After annealing at200°C,UTS and hardness of CR samples(345MPa and HV127)wereimproved as compared to RTR samples(320MPa and HV115).The increase in hardness and UTS of CR samples after annealing at200°C was due to precipitation ofβ''from Al matrix,which imparted higher Zener drag effect as compared to RTR samples.Theimprovement in corrosion and pitting potentials was observed for CR samples(?1.321V and?700mV)as compared to RTRsamples(?1.335V and?710mV).In CR samples,heavy dislocation density and dissolution of Mg4Al3Si4-precipitates in the Almatrix have improved corrosion resistance of the alloy through formation of protective passive layer and suppression of galvanic cell,respectively.
