Microstructural modification and ageing behaviour of the Al–17Si–5Cu alloy using a novel approach

Abstract

ABSTRACTA novel short duration heat treatment schedule is proposed in the present investigation for the Al-17 wt-% Si-5 wt-% Cu alloy (AR alloy). The existing heat treatment uses long duration (4–24 h) holding at solutionising temperature prior to ageing treatment. In the present investigation, the AR alloy is subjected to isothermal holding at 590°C for 15 min followed by warm water quenching prior to the normal ageing schedule. Detailed microstructural investigations involving size and shape of primary as well as eutectic Si particles, porosity measurements along with hardness and tensile property characterisation are carried out to find the effect of isothermal heat treatment. The study reveals considerable improvement in microstructure and mechanical properties after this isothermal heat treatment.