Effect of Heat Treatments on the Microstructure, Hardness and Corrosion Behavior of Nondendritic AlSi9Cu3(Fe) Cast Alloy

Abstract

In this paper we studied the influence of heat treatments on properties of AlSi9Cu3(Fe) nondendritic cast alloy. Solution heat treatment, six hours at 520 °C, while making the grains more spherical modifies corrosion morphology into intergranular corrosion and corrosion surrounding spherical particles in 3 % NaCl solution. Past solution treatment, quenching at 520 °C after one hour with two weeks of natural aging transform the shape of grains into equiaxes form. Two weeks of natural aging and 30 minutes of aging at 150, 200, 250 °C after solution treatment and quenching give birth to the "Chinese script" form of the Al15(MnFe)3Si intermetallic particles. The prolongation of the duration period of aging to one hour at 200 °C is sufficient to transform the morphology of corrosion into located corrosion by pitting, and a longer aging cancels the "Chinese script" form. DOI: http://dx.doi.org/10.5755/j01.ms.19.3.1397

Keywords

• AlSi9Cu3 alloy
• intermetallic phases
• heat treatment
• mechanical properties
• corrosion