Inclusion Analysis In The AM50 Magnesium Alloy By Direct Smelting Of Crude Magnesium

At present, most magnesium alloy production is based on pure magnesium ingot by smelting of crude magnesium. So it needs melting twice, wasting energy, seriously burning, consumption of flux, seriously environmental pollution and the product quality is not stable, high production costs. This article subject to crude magnesium as raw materials, direct smelting magnesium alloy, which strictly control the inclusions by direct melting into the AM50 magnesium alloy. Eliminate the traditional four processes of "fine magnesium melting," "fine magnesium storage", "fine magnesium transport (off-site production)", "refined magnesium alloy". Shorten the process processes, increase productivity, reduce production costs and energy saving.In this paper, SF6, N2 mix as protection gas, refine at 740℃, add 2wt%~3wt% of the refining agent. Through mechanical agitation, ultrasonic mixing and the blow argon refining, barbed wire filtering and other means, it gets fine grains and removes inclusion effectively and pour at 720℃. No filter and filter by direct smelting of crude magnesium and commercial compare them from three aspects: tensile properties, impact properties and corrosion resistance, and then analysis the major element composition size and shape of inclusions on the effects of mechanical properties and corrosion resistance.The results show that: the shapes of inclusions in AM50 magnesium alloys are hexagon, circle, needle, stick, group flocculent ball, dumbbell-shaped distribution of such clusters. The most common is magnesium oxide inclusions. Generally contain Mg, C, O, Si, Fe, Al, Mn, Ca and other elements. AM50 magnesium alloy performance by direct smelting of crude magnesium can be improved effectively by filtering Tensile strength is 183.82MPa, elongation rate is 7.75%, and impact toughness is 8.494J/cm2. Tensile strength of no filter AM50 magnesium alloy is only 166.98MPa, and elongation rate is 7.15%, and impact toughness is 6.69J/cm2. Tensile strength of commercial AM50 magnesium alloy is 184.44MPa, elongation rate is 7.8%, and impact toughness is 8.374J/cm2. The average corrosion rate of no filter AM50 magnesium is 1.65 times faster than filter AM50 magnesium alloy. The average corrosion of AM50 magnesium by direct smelting of crude magnesium is as fast as commercial AM50 magnesium alloy. The corrosion rate of AM50 magnesium alloy increases with time. The properties of AM50 magnesium alloy by direct smelting of crude magnesium meet the needs of commercial AM50 magnesium alloy.