Oxidation kinetic behavior and microstructure mechanism of GH3536 alloy fabricated by laser powder bed fusion

This study comprehensively investigates the oxidation kinetics of laser powder bed fusion (LPBF) processed GH3536 superalloy at 950 °C. The oxidation kinetics and oxide film microstructure characteristics are analyzed and the underlying mechanism is discussed, by comparing with the conventionally manufactured wrought GH3536 samples under the exactly same test condition. The oxidation rate of LPBF samples is faster at initial stage and then tends to flatten out with increase of heating duration time. The finer and equiaxed chromia crystals formed in LPBF GH3536 surface can effectively improve the oxidation resistance comparing to the columnar structure chromia in wrought GH3536. The oxide film with excellent protection in LPBF GH3536 provides an important contribution to the application of GH3536 at high temperature.