Effect of Mn content on microstructure and properties of 6000 series aluminum alloy

The effects of Mn Content on the microstructure and properties of 6000 series aluminum alloy Al–0.91Mg–0.81Si–1.02Cu–xMn–0.2Zr–0.02Sr were studied by means of metallographic analysis, hardness and conductivity test, tensile test, and corrosion test. The results show that when the content of Mn added is 0%, 0.702%, and 1.061%, the intergranular corrosion depth of the corresponding 1#, 2# and 3# alloys is 490.05 μm, 245.02 μm, and 198.99 μm. It is known that the higher the content of Mn added, the better the resistance to intergranular corrosion. It has also been found that when the content of Mn added is 0.702%, the grain size of the alloy is remarkably refined. And as the content of Mn element continues to increase, the degree of grain refinement of the alloy is also higher. In addition, in the process of increasing the Mn element content from 0 to 1.061%, the tensile strength and yield strength of the alloy gradually decrease. And as the content of Mn added increases, the strength decreases more. The elongation of the alloy is quite high, but the increase in the content of Mn has little effect on the elongation of the alloy.