Elevated Temperature Deformation Behaviour and Mechanical Characteristics of Invar Alloy Used for Shadow Mask

WT5BZ]Invar alloy is employed as the material of the shadow mask of a color picture or display tube because of its low coefficient of expansion being beneficial to the gain of high clarity In order to provide the experimental basis for the formation of Invar alloy shadow mask at 200℃, its responses at elevated temperature were observed in the conditions of the static load and uniaxial tension by means of strain gage The results show that for various annealing treatments at 790~850℃, the stresses is evidently dropped with increasing the heating temperature from about 20 to 180℃, and thereafter is fluctuated in 120~130MPa for the yielding strength and in 300~320MPa for the ultimate strength The specific elongation is increased with the rise of annealing and heating temperatures, but the elastic modulus is nearly unchanged