Study On The Calcium Magnesium Alloy Mechanical Properties And Corrosion Behavior

High quality of small, specific strength and specific stiffness,damping resistance, good insulation and electromagnetic and processing convenience is magnesium alloy with a series of advantages, such as in lightweight structure, aerospace and other fields is widely used.And in the field of biological materials, magnesium alloys are promising as degradable metal hard tissue replacement materials because of their excellent bio-activity, bio-compatibility, especially their biodegradability. In this study, alloying elements such as calcium was added into magnesium to prepare different components of Mg-Ca alloys. Then heat treatment andthe microstructure, corrosion behavior and mechanical properties of the alloys were investigated through electrochemical corrosion test, immersion test, hardness test and tensile test, and by using optical microscope, scanning electron microscopy,energy dispersive spectroscopy, X-ray diffraction, universal tensile testing machine and hardness tester.The result shows that the magnesium alloy is mainly composed of Mg phase and Mg2 Ca phase,with the increase of calcium content, the alloys of Mg2 Ca increased, the tensile strength and elongation rate decreases gradually, the yield strength and hardness is greater; Supersaturated α-Mg solid precipitated and fine particulate second phase Mg2 Ca precipitated along the grain boundary, hardness and tensile properties are improved by heat treatment.The corrosion test of alloys shows that,At the same time, the addition of calcium drivesthe accelerate of corrosion rate in a certain extent,and is a direct ratio relationship with the addition Ca. The corrosion current density of Mg-5Ca is the highest, and the corrosion potential is the lowest, so the corrosion propertiesisthe best. After 24 hours, the weight loss ratio of Mg-5Ca is 70%. After the heat treatment corrosion rates decreased significantly, but thecorrosion propertiesof theMg-5Ca is still the best. The corrosion types of the cast and heating treatment Mg-Ca alloys are pitting corrosion and filiform corrosion.