Two-Step Solution Heat Treatment of AlSiCu Alloy for Improvement of Mechanical Properties

Abstract

This paper investigated the effects of two-step solution heat treatment of aluminum alloy for lightweight automotive on mechanical properties. Solution heat treatments in this study are applied to improve of mechanical properties through a single-step and two-step solution heat treatment. The microstructure of AlSiCu casting specimen represents a typical dendrite structure having a secondary dendrite arm spacing (SDAS) of 40 um. In addition to the Al matrix, a large amount of coarsen eutectic Si, Al2Cu intermetallic phases and Fe-rich phases are identified. After solution heat treatment, the mechanical properties of two-step solution heat treatment alloy show higher values than as-cast and a single-step solution specimens. Consequentially, the two-step solution heat treatment could be used in automotive parts to improve mechanical properties.