Effect of gamma ' content on the mechanical behavior of the WASPALOY alloysystem

This article presents the research results of the effects of alloy chemistr y, cooling rate and solution temperature on mechanical behavior, especially for the fatigue-crack growth of the WASPALOY alloy system. It is indicated that tensile strengths, both yield strength and ultimate tensile strength, increase with increasing Al + Ti content in the alloys. The solution tempe rature had almost no effect on the tensile properties of WASPALOY. Cooling rate showed almost no effect on the tensile properties of WASPALOY, but for the alloys with a higher Al+Ti content, the yield strength of the alloys w as improved with increasing cooling rate. The increase in precipitation con tent tremendously improved the stress rupture life of the alloys. The fatig ue-crack resistance of the alloys can be improved by increasing the strengt hening precipitate volume fraction, in spite of the variation of the coolin g rate. The crack growth rates were time-dependent, as expected. The growth rate increased with decreasing loading frequency. However, a higher precip itate content showed a lower time dependence. (C) 2001 Elsevier Science B.V . All rights reserved.