\n\tThe University of Michigan, Ann Arbor, reports its researchers have discovered that nickel-cobalt-iron and nickel-cobalt-iron-chromium-manganese alloys in equal concentrations can be 100 times more resistant to radiation-induced swelling than pure nickel, meaning that radiation-induced cavities in these alloys are 100 times smaller than in pure nickel.<\/p>\n
\n\tColleagues at Oak Ridge National Laboratory in Tennessee created samples of a variety of nickel-based alloys. These were then exposed to radiation in a facility at the University of Tennessee. The most successful alloys were concentrated solid solutions\u2014crystals made of equal parts nickel, cobalt and iron; or nickel, cobalt, iron, chromium and manganese.<\/p>\n
\n\t“These materials have many good properties such as strength and ductility, and now we can add radiation tolerance,” said Chenyang Lu, a U-M postdoctoral research fellow in nuclear engineering and radiological sciences and the leading author of the report in Nature Communications.<\/p>\n
\n\tIn an experiment proposed by Dr. Wang, UT researchers exposed the samples to beams of radiation that created two levels of damage, similar to what may accumulate in a reactor core over several years and over several decades. These experiments were done at a temperature of 932\u00b0F, a temperature at which nickel-based alloys are usually susceptible to swelling.<\/p>\n
\n\tThese samples were analyzed at U-M’s Center for Material Characterization with a transmission electron microscope. The team found that compared to pure nickel, the best alloys had more than 100 times less radiation damage.<\/p>\n