Study On Ballistic Property And Corrosion Resistance Of Magnesium Alloys Extrusion Plates

Magnesium alloys have a series of advantages,such as high specific strength,excellent shock resistance,good energy absorbing property and damping vibration.Magnesium alloys have been widely applied in the field of military equipment.AZ31,ZWK610,ZCK650 and ZCK450 extrusion plates were taken as the research objects in this work.The ballistic property,microstructures and performances of the four magnesium extrusion plates before and after bullet penetration and the corrosion behavior and mechanism were studied.The main results obtained are as follows:(1)Magnesium alloy extrusion plates tests show that:as-extruded AZ31 magnesium alloy mainly consists of ?-Mg and few Mg17Al12(?)phases,it presents complete recrystallization organization and as-extruded ZWK610 magnesium alloy consists of ?-Mg and bulk W phases and has completely tiny dynamic recrystallization grains,incomplete recrystallization grains and abnormal grains;ZCK450 and ZCK650 magnesium alloys both have ?-Mg,MgZnCu and Mg2Cu phases,and present obvious fibrous extrusion microstructures;hardness and tensile test show that AZ31 magnesium alloys has the lowest hardness and tensile strength,and the strength properties of ZWK610,ZCK650 and ZCK450 magnesium alloys increase successively,but the hardnesses decrease instead.(2)Bullet holes micro structure tests show that the ballistic property is directly related to the strength properties,and has little relationship with hardness.The ballistic property of AZ31,ZWK610,ZCK650 and ZCK450 as-extruded magnesium alloys increases successively and AZ31 magnesium alloy's low strength leads to large penetration deformation around bullet hole,and there appears large amounts of twin crystals,the energy absorption effect is limited,so the ballistic property is the worst;ZWK610?ZCK650 and ZCK450 magnesium alloys have higher strength properties,the bullet holes of them happen small penetration deformation,the microstructures after penetration are no obviously difference from the matrix microstructures,indicating that the bullet impact energy on the surface diffuses strongly,energy absorbed scale is larger,so the ballistic property is the best.(3)The main corrosion product of as-extruded AZ31,ZWK610,ZCK650 and ZCK450 magnesium alloys is Mg(OH)2 of cluster petals,and the corrosion type of AZ31 and ZWK610 magnesium alloys is localized corrosion,the corrosion type of ZCK650 and ZCK450 magnesium alloys is homogeneous corrosion.(4)Polarization curve test and the electrochemical impedance spectra of the test show that the corrosion resistance rank of the four as-extruded magnesium alloys is AZ31>ZWK610>ZCK650>ZCK450.Icorr of AZ31 magnesium alloy is the lowest and the diameter of AZ31 magnesium alloy's capacitive reactance arc is the largest,so its corrosion resistance is the worst.Icorr of ZCK450 magnesium alloy is the highest and the diameter of ZCK450 magnesium alloy's capacitive reactance arc is the smallest,so ZCK450 magnesium alloy's corrosion resistance is the best.