An experimental investigation of the effects of radiation and thermal parameters on the aluminum 1050 obtained from upward directional solidification

Abstract

During the reactor operation, aluminum tank and the core components can experience radiation damage, resulting in limitation of its life span. Effects of radiation on the aluminum alloys are not yet fully understood, especially when material is obtained from upward directional solidification under transient heat-flow condition. For this paper, an experimental research has been conducted to investigate the radiation effects on the as-cast aluminum 1050, with focus on the microstructure, microhardness and porosity for different position along casting. Firstly, thermal parameters were determined during solidification experiment and then correlated with cellular spacings, microhardness and porosity content. The experimental results show that thermal parameters such as solidification speed, thermal gradient and cooling rate exerts an influence on the microstructure, microhardness and porosity. Experimental laws for microstructure, microhardness and porosity have been determined, indicating that the increase in thermal parameters has induced a refinement effect on the microstructure, increase in microhardness and a decrease in the porosity content. Further, measurable effects of the gamma radiation on the microstructure, microhardness and porosity formation along the ingot of aluminum 1050, were experimentally determined. It stands out among results that gamma radiation has favored an increase in cellular spacings, microhardness and porosity in ingot, obtained from a vertical upward directional solidification. However, even after the gamma radiation exposure, microstructure, microhardness and porosity found along the casting are dependent of the solidification thermal conditions.

Keywords

• Gamma radiation
• Microstructure
• Microhardness
• Porosity
• Directional solidification