Precipitate Stability In A Zr-2.5nb-0.5cu Alloy Under Heavy Ion Irradiation

The stability of precipitates in Zr-2.5Nb-0.5Cu alloy under heavy ion irradiation from 100 degrees C to 500 degrees C was investigated by quantitative Chemi-STEM EDS analysis. Irradiation results in the crystalline to amorphous transformation of Zr2Cu between 200 degrees C and 300 degrees C, but the beta-Nb remains crystalline at all temperatures. The precipitates are found to be more stable in starting structures with multiple boundaries than in coarse grain structures. There is an apparent increase of the precipitate size and a redistribution of the alloying element in certain starting microstructures, while a similar size change or alloying element redistribution is not detected or only detected at a much higher temperature in other starting microstructures after irradiation.