Processing ODS Modified IN-625 Using Selective Laser Melting

Date
2015
Authors
Spierings, A.B.
Bauer, T.
Dawson, K.
Colella, A.
Wegener, K.
Journal Title
Journal ISSN
Volume Title
Publisher
University of Texas at Austin
Abstract

Increasing the operating temperatures of power plant turbine generators is a universal method to increase the efficiency of steam and gas turbines. However, operating a plant at higher temperatures poses extreme challenges to the materials used, especially regarding oxidation, creep, thermal fatigue- and stress-corrosion cracking. The EU-OXIGEN project addresses these issues by the development of novel processing routes for ODS-modified materials, as this class of materials offers exceptionally high temperature strength, oxidation and corrosion resistance at temperatures exceeding 900°C. Additive manufacturing processes such as Selective Laser Melting are considered to enable their successful processing. First results on density of SLM-processed, mechanically alloyed ODS-modified Inconel-625 superalloy powders, are presented and compared to the processing conditions and results of gas atomized conventional Inconel-625 powders. Whereas for IN625 a wide and stable processing window was found, significant differences for the ODS variant in terms of the required laser energy input to reach density values >99% are found. Microstructural analysis of precipitates lead to the conclusion that the milling process for ODS variant is key to achieve good quality materials and results.

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