Study On Refining Process Of AZ61 Magnesium Alloy

Magnesium alloys have low density, light weight, strength, stiffness, high heat resistance, good shock absorption, convenient recycling use and other characteristics, which make it have the potential of widely using in aerospace, transportation, weapons, 3C products and other fields,and almost all the countries increase the intensity of researching economic and efficient method for purifying magnesium alloy to significantly improve properties of it, and promote its applicaton.At persent, the main problem in magnesium alloy production is stoma, inclusion and others, this paper through existing laboratory equipment and self made mold to cast magnesium alloy, conducts the water simulation and experient of refining AZ61 magnesium alloy by Ar stirring, and experiment of refining by C2Cl6 metamorphism. Rolling by six roller mill after the slab peeled, and RTA and uniform annealing at 350℃,explore the effect of removing inclusion and the influence on Mechanical Properties of AZ61 magnesium alloy by different process.The results are as follows:(1) Among the factors the way of blowing Ar, gas flow, the location of the nozzle, the last has the minimal effect on blending time. When the gas flow is the same, Tee junction two blowing nozzle to blow Ar is more conducive to the smooth surface than the other way around.(2) SF6 + Ar mixed gas protected melting AZ61 magnesium alloy, the effect is good, size of inclusion is all blow 50μm, the effect of blowing Ar and C2Cl6 purification on inclusion is obviously, the inclusion concent of the best experimental alloy down to 0.58% and 0.53% respectively from 1.37% before purification.(3) Fast solidification will form different shapes, sizes of Mg-Al precipitates, and mostly in group form, the matrix all has different degree of oxidation.(4) Blowing Ar has no effect on precipitates, but C2Cl6 can effectively decrease them, and the area rate of them in the experimantal alloy purified by C2Cl6 in the way of Gradually adding down to 0.46% from 8.34% of unpurified alloy.(5) Before and after rolling, annealing and uniform annealing, type and size of inclusion of all the experimental alloys has no variation, thus, rolling, annealing and uniform annealing has no effect in decreasing both inclusion concent and size.(6) After purification alloy elongation significantly enhanced, the elongation of the best experimental alloy of blowing Ar and C2Cl6 purication increase to 7.09% and 7.02% expectively from 4.02% before purification.(7) After annealing, the precipitates in the alloy is much smaller and more uniform, produce dispersion strengthening effect. This may be the reason of the tensile strength of the alloy after annealing is better than that of the former.(8) Heating process is equivalent to short-term high-temperature tensile annealing, it makes the precipitates uch smaller and more uniform, produce dispersion strengthening effect, The tensile strength of that part of the experimental alloy 250 ℃higher than 175 ℃.