A comparison study of microstructure, texture and mechanical properties between two 6xxx aluminum alloys

Abstract

This paper investigates a comparison study of microstructure, texture and mechanical properties between two 6xxx aluminum alloys through microstructure, texture characterization and tensile test. The results show that they exhibit different microstructure, texture and mechanical properties. In comparison with the alloy sheet with a low weight ratio of Mg to Si (Si-excess), the alloy sheet with a higher weight ratio of Mg to Si (Mg-excess) and additional Zn possesses the finer as-casting and solution treated equiaxed grain structure, less particles with larger size before solution treatment, weaker recrystallization texture mainly including Cube {001}<100> orientation and weaker mechanical properties. The low weight ratio of Mg to Si corresponds to slightly higher yield strength and ultimate tensile strength, but much higher plastic strain ration r, work hardening exponent n values and elongation. Interestingly, Portevin-Le Chatelier (PLC) effect is very prevailed in the alloy sheet with a higher weight ratio of Mg to Si and additional Zn, which is responsible for the low elongation and r value. The alloy containing a low weight ratio of Mg to Si may be beneficial to improve comprehensive mechanical property.