Research Of Refining Process Of 7075Al Alloys By Spinning Rotor Degassing

The 7075 aluminum alloys have been widely used to aviation, aerospace, defense, weapons, transportation, and other fields because of their high strength. However, every year a large amount of spoiled products of 7075 aluminum alloys have been produced because of high levels of gas content. Therefore, explore a new refining process and provide a reasonable refining process to increase the degassing rate of 7075 aluminum alloy has become the focus of the study at home and abroad.First, this paper explored the factors of the spinning rotor degassing purification process on the 7075 aluminum alloys refinement, the result shows that the rotational speed of rotor has significant effect on purification efficiency, gas flow and refining time have a little effect, and purification effect of geostationary time is the least. The optimum purification parameters selected by orthogonal table as follows, rotor speed of 400 r / min,inert gas flow of 0.4 ml / h, refining time of 15 min, and geostationary time of 6 min.Second, the comparison of degassing rate between spinning rotor degassing purification process and conventional C2Cl6 purification had been studied. The result shows that the degassing rate of the traditional C2Cl6 refining method is 30 percent, and the degassing rate of spinning rotor degassing can reach up to 70 percent.On the basis of these studies, the C2Cl6 and spinning rotor degassing mixed purification had been studied. The result shows that degassing rate of this mixed purification can reach up to 78 percent.Finally, the porosity distribution of samples under various process parameters was to be observed, and the hardness and tensile property were measured. The influence of heat treatment on the porosity distribution and mechanical properties of the samples had also been researched. The result shows that: the samples used by C2Cl6 refining have higher levels of porosity, the average hardness (HRB) value of 55, and the tensile strength,yield strength and elongation of 352MPa, 318MPa and 4.2% respectively, the samples used by spinning rotor degassing purification have lower levels of porosity content, the average hardness (HRB) value of 63, and the tensile strength,yield strength and elongation of 396MPa, 358MPa and 4.7% respectively. The C2Cl6 and spinning rotor degassing mixed purification have the minimum porosity content, the average hardness (HRB) value of 67, and the tensile strength,yield strength and elongation of 446MPa, 398MPa and 5.3% respectively. The hardness, tensile strength, yield strength and elongation of 7075 aluminum alloys used by spinning rotor degassing purification have been increased after the solution and aging heat treatment, and the effect after aging is better than that of after solution treatment.