Effect of thermal ageing on the tensile properties of hot and cold rolled commercial high conductive metal and its alloy

The rolling of a metal or its alloy has close association with the thermo-mechanical properties, and this phenomenon is important for conducting materials as these materials need to maintain thermal or electrical conductivity along with desirable tensile properties for their useful life. It necessitates looking for the relationship between rolling condition and aging temperature of conductive materials to establish the influences on their mechanical properties. As such, the present research is an attempt to investigate the effect of thermal aging on the mechanical properties and microstructure of commercially available high conductive material. Here, the samples are prepared from copper ingots and copper based alloy collected from local market. From the bulk material, long bars are taken, and they are at first homogenized and then solution treated. Some of the bars are kept free from rolling and others are rolled in two conditions. Few bars are rolled at room temperature to reduce the thickness by 80% and few bars are hot rolled by 40% and then cold rolled by further 40% making final reduction by 80%. Then a series of experiments are carried out to determine the changes in micro-hardness, strength, elongation and microstructure of samples as a function of thermal aging temperature. Most of the mechanical properties after thermal aging are found to be influenced quite significantly by the condition of rolling.