Application of the Positive Thermoelastic Coefficients of Nickel-Iron Alloys to Wide-Temperature-Range Belleville Springs

A method for producing a spring of constant spring-rate versus temperature up to the range of 1000 deg F is presented by series stacking of Belleville spring washers. Several different materials possessing the correct combinations of positive and negative thermoelastic coefficients may be utilized. Materials investigated in this study are types 304 and 430 stainless steels, and 31, 42, 49 Ni-balance Fe alloys. Experimental results for several material combinations are given along with the theoretical predicted results.