Effects of Ru and Re additions on the high temperature flow stresses of Ni-base single crystal superalloys

The strengthening effects of Re and Ru additions in high refractory content single crystal Ni-base superalloys were investigated. An electro-thermal mechanical testing (ETMT) unit was used to measure the high temperature flow stresses of five experimental Ni-based superalloys containing varying levels of Re and Ru. Flow stresses of single phase γ and γ′ alloys with compositions representative of the constituent phases found in superalloy single crystals were also measured. Significant increases in flow stress were observed with the addition of Ru or Re. For similar alloying levels in wt%, additions of Re were more effective in strengthening the single crystal alloy when compared to addition of Ru.