Effect of Deformation on Mechanical Properties and Microstructure of Al-1%Cu-0.96%Mg-0.36%Si (mass%) Alloy

Abstract

In this study, we investigated the effect of a combination of deformation and aging after solution heat treatment of an Al-1%Cu-0.96%Mg-0.36%Si (mass%) alloy on the precipitation during subsequent artificial aging. The combination of microstructural studies and hardness tests allowed for a detailed characterization of the precipitation in the preformed material. The main phase in the deformed condition is the S′ phase. Aging time-hardness curves, DSC analysis, microstructural examination, and heat treatment optimization were performed to understand the precipitation process in more detail. The results showed that high hardness can be achieved in a short period of time. The aging process is also analyzed to compare the peak aging period and the hardness level of the material. We then compared the thermal aging process with three different cold-rolling conditions and concluded which condition has the most suitable properties for commercial purposes.

Fig. 7 Bright-field TEM image of three cold-rolling conditions which are pre-aging at 100°C, then cold rolling, artificial aging at 160°C peak aging (a), (b) 0%CR, (c), (d) 30%CR, (e), (f) 60%CR, (g), (h) 80%CR and SAED pattern corresponds to each condition in a horizontal row.