محيا شمسيان جزه

The use of metals at high temperatures, especially at temperatures above 50% of their melting point, reduces their strength and other mechanical properties. Therefore, to eva‎luate the ability of a metal at high temperature, it is necessary to determine the characteristics of the flow behavior and other mechanical properties, including free fatigue behavior at high temperature. Among the materials used at high temperatures, nickel-based superalloys have been developed as the best materials for working at high temperatures. The properties of these alloys depend on their microstructure and the appropriate microstructure of these alloys can be created by various heat treatment, mechanical and thermomechanical. In the present study, which investigated the nickel-base superalloy X-750, it was first attempted to study the effect of different two-stage ssolution and aging heat treatment cycles on the microstructure of the specimens and then the effect of this change on the microstructure on the tensile, The hardness and fatigue properties of the alloy are examined. The results of these studies have shown that me chanical properties can be improved by decreasing the size and increasing the gamma fractional fracture. Therefore, optimum heat treatment conditions were obtained to obtain the maximum gamma fracture volume and the smallest size in this study and based on these parameters, the most desirable mechanical properties were extracted. The results show that the highest gamma fractional volume fraction and the lowest mean particle size are obtained under heat treatment cycle of FC-705 and AC-845.

IN X-750- Heat treatment of superalloy - Hardening precipitated superalloy- Room temperuture tensile test- fatigue test.

IN X-750- Heat treatment of superalloy - Hardening precipitated superalloy- Room temperuture tensile test- fatigue test.