Effects of Temperature on the Mechanical Properties of U-2.5%Nb Alloys

The mechanics properties of U-2.5%Nb alloy from -100 to 700 degrees C were studied. The results show that alloy tensile strength decreases with the temperature increasing, The plasticity isn't monotone change below 600 degrees C, and the elongation ratio and the area reduction ratio obtain the minimums value near 500 degrees C. The tensile fracture morphology along grain boundary rupture presents obviously contrast room temperature, and the plasticity increases obviously beyond 600 degrees C. Upon heating up to 500 degrees C, for 1 h and then cooling to room temperature(20 degrees C), the impact toughness of the alloy decreases in contrast to no heating up. In the range of -100 degrees C similar to room temperature, the impact toughness of the alloy decreases with the temperature decreasing, the ductile-brittle transition temperatures of U-2.5%Nb alloy is in the range of -30 similar to-10 degrees C, the trend mentioned above becomes weak below -30 degrees C. The fracture plane is irregular after the impact test, which has a rupture characteristic of quasi-cleavage.