Rate of workhardening influencing subzero temperature tensile strength properties of heat treated aluminium alloy 7010 plates

Abstract

The tensile properties of aluminium alloy 7010 plates, heat treated to varying aging conditions, i.e. naturally aged, underaged, peak aged and overaged, were examined at ambient and subzero (−50°C) temperatures. It is shown that the maximum increase in strength properties (both 0·2% proof stress and ultimate tensile strength) upon changing the test temperature from ambient to subzero (i.e. −50°C) is obtained in the case of the naturally aged samples, while there is a minimal increase in the strength properties of the underaged samples when tested at −50°C. These results are discussed in light of changes in the workhardening behaviour of the materials with aging.

Keywords:

• Al–Zn–Mg–Cu–Zr alloy 7010
• Aging
• Tensile properties
• Workhardening
• Transmission electron microscopy

The authors wish to acknowledge the financial support from the Defence Research and Development Organisation (DRDO), Government of India.