| Magnesium-based composite materials have gained more and more in aerospace,automotive,electronics,transportation and other fields due to their high specific strength,modulus,hardness,dimensional stability,and excellent wear resistance,shock absorption performance and high temperature performance.Widespread concern.However,its mechanical properties are poor,which limits its further application.In order to improve the mechanical properties of magnesium matrix composites,Mg3Sb2/Mg and?Mg3Sb2+AlSb?/Mg composites were synthesized by powder metallurgy.Firstly,the Gibbs free energy and Sb content?wt%and the same?at 298K,400K,600K,800K,1000K and 1200K were calculated as adiabatic temperatures of 7.7%,15.4%and 23.1%,respectively.Studying Mg3Sb2 enhanced magnesium The synthesis mechanism of matrix composites.Then,Mg3Sb2/Mg and?Mg3Sb2+AlSb?/Mg composite materials are prepared by mixing powders of different amounts of Mg powder,Sb powder,and Mg powder,Sb powder,and Al powder having different distribution ratios by powder metallurgy.The phase composition and microstructure of the composites were analyzed by XRD and SEM.The mechanical properties of Mg3Sb2/Mg and?Mg3Sb2+AlSb?/Mg composites were tested by microhardness tester and tensile tester.The Mg3Sb2 was studied by electrochemical experiments.Corrosion resistance of/Mg,?Mg3Sb2+AlSb?/Mg composites;Corrosion and wear properties of Mg3Sb2/Mg,?Mg3Sb2+AlSb?/Mg composites were analyzed by corrosion wear test.The effect of sintering temperature on the microstructure of?Mg3Sb2+AlSb?/Mg composites was investigated.The results showed that the reaction of 3Mg+2Sb=Mg3Sb2 could be spontaneously carried out;when the content of Sb was 7.7%,15.4%,23.1%,the synthesis of Mg-Sb could not occur spontaneously;the synthesis temperature of intermetallic compound Mg3Sb2 was 544.58°C,621.84°C and 666.14°C.When the temperature is 544.58°C and 621.84°C,Mg and Sb exist in the solid phase,and 3Mg?s?+2Sb?s?=Mg3Sb2?s?reaction occurs at the solid-solid interface of Mg and Sb,and the surface diffusion is dominant.When the temperature is 666.14°C,the sintering process is liquid phase sintering,which is mainly volume diffusion.The powder metallurgical reaction synthesis method can prepare Mg3Sb2/Mg composite materials with different distribution ratios.When the Sb content was 7.7%,15.4%,23.1%,respectively,the intermetallic compound Mg3Sb2 was observed to grow with the increase of Sb content.The microhardness of Mg3Sb2/Mg composite increased with the increase of Sb content.When the tensile strength increases,the tensile strength increases first and then decreases.The corrosion potentials are-1.53V,-1.45 V,-1.47 V,respectively.The corrosion current densities are 3.281×10-5A·cm-2.1.75×10-6A·cm-2,3.35×10-6A·cm-2.Under the action of 3.5%NaCl solution and friction,the corrosion friction coefficient of Mg3Sb2/Mg composite decreases with the increase of Sb content.CoMParing the properties of Mg3Sb2/Mg and?Mg3Sb2+AlSb?/Mg composites,the mechanical properties and corrosion resistance of?Mg3Sb2+AlSb?/Mg composites are better than those of Mg3Sb2/Mg composites,but their wear resistance is better.difference.Under the conditions of sintering temperature of 650°C,700°C,750°C and 800°C,the microhardness and tensile strength of?Mg3Sb2+AlSb?/Mg composites increase first and then decrease with the increase of sintering temperature.At750°C,the microhardness is 71 HV and the tensile strength is 167 MPa.The sintering temperature is700°C.The self-corrosion potential of?Mg3Sb2+AlSb?/Mg composite is-1.36V,which has the highest corrosion resistance good. |
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