Influence of Addition of Nickel on the Thermal Expansion, Rigidity Modulus and Its Temperature Coefficient of the Alloys of Cobalt, Iron and Chromium, Especially of Co-elinvar. I : Additions of 10 and 20 per cent of Nickel

The influence of additions of 10 and 20 per cent of nickel on the thermal expansion in the range from 10 to 50°, rigidity modulus at 20°and its temperature coefficient in the range from 20 to 50°of the alloys of cobalt, iron and chromium was studied. The relations between those properties and the concentrations of nickel-added alloys were almost similar qualitatively to those in the case of the ternary alloys of cobalt, iron and chromium, that is, there were two groups of alloys, one showing a positive temperature coefficient of rigidity modulus and the other a negative. In the case of addition of 10 per cent of nickel, the smallest thermal expansion coefficient was 2.20×10^, while in the case of addition of 20 per cent, it was 1.69×10^. The largest positive values of the temperature coefficients of rigidity modulus in the corresponding cases were respectively+46.7×10^ and + 66.0×10^. The largest and smallest values of rigidity modulus in the case of addition of 10 per cent of nickel were 9.10×10^5 kg/cm^2 and 6.00×10^5 kg/cm^2, and in the case of 20 per cent of nickel they were respectively 8.36×10^5kg/cm^2 and 5.09×10^5kg/cm^2