Influence of external and internal cooling at solidification on strength of brittle duralumin in compression

Abstract

Details of machines, mechanisms or other structural elements can be made of metal castings. Cooling of such castings starts from the outside during solidification under normal conditions. The temperature of the inside layers exceeds the temperature of the surface layers in this process. After reaching the ambient temperature, the surface layers stop shortening due to a decrease in temperature. Thus, they prevent the reduction of the inside layers, the temperature of which is higher. When the temperature is aligned in the cross section due to the final cooling of the casting, the surface layers will be compressed, and the inside will be tensioned. The stresses fluctuate smoothly from the surface of the sample to the core (the inside part), trying to deplan the section (they are called deplanatory stresses).