Effect of Powder Treatment on Oxygen Content， Microstructure and Mechanical Properties of FGH95 Superalloy

Abstract

The effects of powder particle size， powder treatment technology and powder treatment environment on oxygen content of FGH95 alloy were studied by chemical composition analysis， scanning electron microscope， transmission electron microscope （TEM） and mechanical property detection. The results showed that the powder treatment environment had great influence on the oxygen content and microstructure of FGH95 alloy， and the oxygen content of the alloy was increased by 115% compared with that of the degassed alloy prepared in the inert gas environment after the atomized powder treated in air with the same particle size， the oxygen content of FGH95 alloy prepared in low oxygen environment was only 0.003 9%， which significantly improved the PPB structure in the alloy.Similarly the oxygen content of FGH95 alloy prepared by 0-45 μm powder increased by 33% than that by 0-75 μm powder after the degassed treatment at room temperature and 450 ℃ in the inert gas environment. Powder treatment temperature has little effect on oxygen content of alloy which prepared by powder treated in low oxygen environment under the same conditions. The FGH95 alloy with different oxygen content had little effect on the strength at room temperature， but the ductility of the alloy was decreased with the increase of oxygen content.

Keywords

• nickel-based superalloy； powders； oxygen content； hot isostatic pressure； microstructure； mechanical properties