The Effect Of Inhibitor And Aluminum Coating On The Corrosion Resistance Of Magnesium Alloy Under The Action Of Friction Stir Processing

The AZ31 magnesium alloy was friction stir processed,and its microstructure was observed.In 5%(mass fraction)NaCl solution added different inhibitors,the corrosion performance of friction stir processed magnesium alloy was explored in different conditions by electrochemical methods.Besides,an aluminum-magnesium composite plate was fabricated by friction stir processing method,and the effect of aluminum coating on the corrosion behavior of magnesium alloy was studied.Results showed that:1 The grain of friction stir processed(FSP)magnesium alloy was more refined and uniform,the surface state of the material was improved.Sodium carbonate has obvious inhibition effect on magnesium alloy base materials and FSP magnesium alloy,increasing concentration of sodium carbonate and adsorption time can make inhibition effect more obvious,but high temperature was not conducive to the function of sodium carbonate.The inhibition effect of sodium tungstate on AZ31 magnesium alloy and FSP magnesium alloy was not as obvious as that of sodium carbonate,and there is a limit value of concentration.In the same condition,the inhibition effect of FSP magnesium alloy was better than that of base metal,and the effect of inhibition was related to the surface state of the material.2 Thiourea has certain inhibition effect on AZ31 magnesium alloy base material and FSP magnesium alloy,the increase of concentration of thiourea was propitious to the improvement of inhibition effect;there is a critical temperature during thiourea inhibition on magnesium alloy,high temperature was not conducive to the thiourea effect;friction stir processing was beneficial to the adsorption of thiourea.3 Thiourea-sodium carbonate and thiourea-sodium tungstate compound have obvious inhibition effect on FSP magnesium alloy,which indicated inhibition synergistic effect among them;with the increase of the concentration of thiourea,the inhibition effect of FSP magnesium alloy was more obvious,and better than that of the base material under the same conditions.4 An aluminum-magnesium composite plate,which has good interface,can be fabricated by friction stir processing method,the aluminum coating can significantly improve the corrosion resistance of magnesium alloy.