Effect of heat treatment on microstructure and oxidation properties of Inconel 625 processed by LPBF
Journal article, 2020

This paper presents a study of the microstructure evolution due to oxidation exposure of Inconel 625 (IN625) alloy produced by Laser Powder Bed Fusion (LPBF). IN625 is a nickel-based superalloy characterized by good mechanical properties, excellent oxidation, and corrosion resistance from cryogenic temperatures up to 980 °C, allowing its wide use in various harsh environments. In order to enable the application of LPBF IN625 components at high temperatures, the oxidation properties and microstructure of as-built and post-heat treated LPBF IN625 alloy must be carefully investigated. For this reason, an extensive characterization of the oxidation behavior of the alloy in the as-built condition and after solution treatment was performed. For both these conditions, the oxidation treatments were performed at 900 °C up to 96 h. The characterization was performed using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and scratch test analysis. The characteristics of the oxide layer and formed phases were investigated. The as-built IN625 state presented greater oxidation resistance compared to the solutionized IN625 one. The latter condition showed a defected oxide layer with the presence of Nb and Ni oxides inside the Cr oxide layer.

Laser powder bed fusion


Nickel-based superalloys

Inconel 625

Additive manufacturing

Microstructure evolution


Simone Parizia

Polytechnic University of Turin

Istituto Italiano di Tecnologia

Giulio Marchese

Polytechnic University of Turin

Masoud Rashidi

Chalmers, Industrial and Materials Science, Materials and manufacture

Nanyang Technological University

Massimo Lorusso

Istituto Italiano di Tecnologia

Eduard Hryha

Chalmers, Industrial and Materials Science, Materials and manufacture

Diego Manfredi

Polytechnic University of Turin

Sara Biamino

Polytechnic University of Turin

Journal of Alloys and Compounds

0925-8388 (ISSN)

Vol. 846 156418

Subject Categories

Manufacturing, Surface and Joining Technology

Metallurgy and Metallic Materials

Corrosion Engineering



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