ELASTIC AND PLASTIC PROPERTIES OF CRYSTALLINE SOLIDS AT ELEVATED TEMPERATURE

• Main Authors: Lytton,Jack L, Hren,John A, Kamber,Kenneth T, Ardell,Alan J, Barrett,Craig R
• Format: Report
• Language: English
• Subjects: ALUMINUM ALLOYS; COBALT; COBALT ALLOYS; COPPER ALLOYS; CREEP; CRYSTAL SUBSTRUCTURE; DIFFUSION; ELASTIC PROPERTIES; FERROMAGNETIC MATERIALS; GRAIN BOUNDARIES; HIGH TEMPERATURE; IRON; IRON ALLOYS; NICKEL; PLASTIC PROPERTIES; STRESSES; TENSILE PROPERTIES; ZINC ALLOYS

It was shown that the strength of pure polycrystalline metals at elevated temperature is controlled primarily by the rate of atomic mobility and the elastic modulus. The apparent activation energy for creep is shown to be greater than that for self-diffusion. If appropriate corrections are made for the change of elastic modulus with temperature, then the activation energy for creep is equal to that for self-diffusion. As a result of this investigation, new creep and stress-rupture parameters are proposed. Ferromagnetism or order can play an important role in increasing the high temperature strength of crystalline solids. The elastic and plastic properties of ferromagnetic Fe, Co, Ni and ordered FeCo, Fe3Al and CuZn were evaluated. The elastic and plastic properties of polycrystalline copper were studied in the temperature range from 400 to 950C. The types of substructure developed during high temperature creep of highly textured polycrystalline Fe - 3% Si sheet were examined by electroetching of dislocation sites.