Thermal expansion of cast and of swaged chromium

Data were obtained on the linear thermal expansion of six samples of chromium (99.2 to 96.3 percent) at various temperatures between -190 0 and + 707 0 C. The expansion curves indicated anomalies at low temperatures. These anomalies were reversible on heating and cooling. The temperature at which anomalous expansion occurs appears to decrease with decrease in the purity of the chromium. Hysteresis was not observed on heating cast or swaged chromium to 300 0 C and cooling to low temperatures. Exceptionally low average coefficients of expansion were found for temperature ranges in or near the anomalous regions. The average coefficients of expansion of the samples of chromium from 20 0 C to various temperatures between 100 0 and 700 0 C lie between 5. 7X 10-6 and 10.3X 10-6 per degree centigrade.