Irradiation-Induced Creep and Microstructural Development in Precipitation Hardened Nickel-Aluminium Alloys

摘要

Irradiation-induced creep in solid-solution Ni-8.5 at% Al and precipitation-hardened Ni-13.1 at% Al alloys was studied by bombarding miniaturized specimens with 6.2 MeV protons at 300 C under different tensile stresses. Results show that the irradiation creep rates of both Ni-Al alloys are only weakly dependent on Al-concentration and pretreatment. Creep rates are comparable with other solution-hardened Ni alloys and commercial stainless steel. Irradiation changes the precipitate structure, and with increasing dose a splitting of the preexisting precipitates into smaller fragments is observed. Irradiation-induced growth of gamma' precipitates in quenched Ni-13.1 at% Al alloys by a displacement rate of 0.000002 dpa/sec at 300 C is comparable to the growth under thermal aging at 570 C. The solubility of Al in Ni is enhanced by irradiation.