Book Description

The effect of temperature on the unnotched and notched Charpy impact properties of plutonium was studied in the alpha, beta, gamma, and delta phases encompassing a temperature range of -43 to 330 deg C. Impact energies for unnotched specimens generally increased with increasing test temperature in the alpha and beta phases. Brittle failures were obtained in these phases. The specimen tested in the gamma phase did not fracture but bcnt in ofi U-shape and pulled through the anvil. lmpact energies for the Charpy V-notched specimens were much lower than for the unnotched spcc(mens.dt corresponding temperatures. Brittle failures were obtained in the alpha and beta phases; some ductility was evidenced in the gamma phase while the specimen tested in the delta phase did not fracture but bent in a U-shape. It was concluded that the beta phase is quite sensitive to both strain rate and notch effects. Fracture appearance in the alpha and beta phase is discussed from the standpoint of grain boundary effects and microcracking. (auth).