Scandium Aluminium Magnesium Alloy Sheet, Forgings And Rod Of The Preparation, Organization And Performance

In this work, the effect of stabilizing annealing on the microstructure and properties of5B70cold-rolling alloy sheet and hot forging-cold pressing profile was discussed with tensile properties and Brinell hardness test, electroconductivity measurement, optical microscope(OM) technology, transmission electron microscopy (SEM) and transmission electron microscopy (TEM) analysis method. And the contrast study of microstructure and properties of5A06and5B70hot rolling bar, hot forging and hot forging-cold pressing5B70profile was conducted, respectively. The results showed that:1) The optimal stabilizing annealing regime of cold rolling5B70alloy sheet was320℃/1h. On this condition, the tensile strength, yield strength and elongation reached410MPa,325MPa and15.3%, respectively.2) According to the experiment, the thermal conductivity was119.0W·m-1·K-1, modulus of elasticity was68.9GPa, and the average thermal expansion coefficient in the temperature range20～50℃,20～100℃,20～150℃was21.6×10-6·℃-1,26.4×10-6·℃-1,26.8×10-6·℃-1, respectively.3) The tensile strength, yield strength and elongation of hot-extruded5B70alloy rod containing minor Sc and Zr was388MPa,245MPa and23.2%. Compared with the5A06alloy, tensile strength and yield strength increased by4.3%and28.3%, respectively. Meanwhile, the elongation maintained a high lever at23.2%.4) The radial tensile strength, yield strength and elongation of5B70hot forging was358MPa、245MPa and24.3%, respectively. After a cold pressing treatment, tensile strength and yield strength increased by34MPa and74MPa while elongation decreased to15.9%.5) There are three kinds of strengthen mechanism in5B70alloy containing minor Science and Zr:grain refining strengthening, substructure strengthening and Al3(Sc,Zr) second phase strengthening.