Study On The Fabrication And Properties Of Silicon Carbide Particles Reinforced Magnesium Matrix Composites

Because magnesium alloy at room temperature and high temperature exhibit lowhardness, low strength, and poor corrosion resistance, which hinder its application in industry.The preparation of reinforced magnesium matrix composites by adding reinforcement greatlyimproves the comprehensive mechanical properties of the magnesium alloy matrix. Thispaper presents the use of SiC particles as reinforcement to a preparation of SiCp/AZ91Dmagnesium matrix composites. And we systematically studied that reinforced mechanism ofSiC particles reinforced magnesium matrix composites, microstructure, fracture morphologyand comprehensive mechanical properties.In this paper, SiCp/AZ91D magnesium matrix composites were prepared on differentpreparation process, which included squeeze casting and gravity casting. The orthogonalexperiment was adopted to study the effect of particles content, particle size, pouringtemperature, extrusion stress on the properties of composite. Through range and varianceanalysis, the significant factors and optimized experimental parameters were also determined.The effect of particles content, size and pouring temperature on material properties werestudied under gravity casting. Combined with the examination of metallurgical structure,fracture morphology and mechanical properties to determine particle reinforced mechanism,materials mechanism of fracture and microstructures. The density, tensile strength, elongation,hardness and microstructures of the SiCp/AZ91D magnesium matrix composites, which wererespectively prepared by squeeze casting and gravity casting were analysisedcomparatively.The experimental results showed that the mechanical properties of SiCparticulate reinforced AZ91D magnesium matrix composites rendered by squeeze castingwere better than those of gravity casting. The part mainly studied the effect of particles content and extrusion pressure on themicrostructure and mechanical properties of SiCp/AZ91D magnesium matrix composites. Theexperimental results indicated that when the extrusion pressure was certain, the hardness ofcomposites was on the raise with the increase of particle content, however, the elongation wason the decline and tensile strength first increased then decreased. And when particle contentwas certain, tensile strength and elongation were first increased then decreased with theincrease of extrusion pressure and when the extrusion pressure reached100MPa, which waswhen the composites reach the best quality.Using optimal experimental parameters, SiC particles reinforced magnesium matrixcomposites were prepared by squeeze casting, and then which were treated by solid solutiontreatment and ageing treatment. The results showed that the mechanical properties ofcomposites obtained a great enhancement through solid solution treatment and ageingtreatment. The tensile strength was193.1MPa before heat treatment and231.5MPa after heattreatment, which was increased at a percentage of19.9%. The elongation was4.32%beforeheat treatment and5.38%after heat treatment, which was increased at a percentage of24.5.The hardness reached73.23HB before heat treatment and81.13HB after heat treatment,which was increased at a percentage of10.8%.