High temperature tensile properties of a series of nickel-base superalloys on a γ/γ′ tie line

A series of nickel-base superalloys with γ′ fractions changed from 0 to 100 mol% and with γ and γ′ compositions kept constant were designed and examined in terms of high temperature tensile properties. temperature range from 900 to 1000°C, 0.2% proof stress shows a maximum at about 85 mol% in a corrected amount of γ′, whereas at 1100°C, it shows maximum at about 65 mol%. The maximum shift of proof stress from the law of mixture in strength was constant for these temperatures. In the strain rate range from 10−8 to 10−2/s at 1000°C, the maximum shift of proof stress increased with the strain rate. The proportion of the shift stress to the proof stress becomes larger as the temperature increases.