Enhanced Oxidation Resistance of Mo–Si–B–Ti Alloys by Pack Cementation

  • Daniel Schliephake
  • Camelia Gombola
  • Alexander Kauffmann
  • Martin Heilmaier
  • John H. Perepezko
Original Paper

DOI: 10.1007/s11085-017-9730-8

Cite this article as:
Schliephake, D., Gombola, C., Kauffmann, A. et al. Oxid Met (2017). doi:10.1007/s11085-017-9730-8
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Abstract

As new high-temperature structural materials, Mo–Si–B alloys satisfy several requirements such as oxidation and creep resistance. Recently, novel Ti-rich Mo–Si–B alloys have shown an increased creep resistance compared to Ti-free alloys. However, due to the formation of a duplex SiO2–TiO2 oxide layer, which allows for fast ingress of oxygen, the oxidation resistance is poor. To improve the oxidation resistance, a borosilicate-based coating was applied to a Mo–12.5Si–8.5B–27.5Ti (in at.%) alloy. After co-deposition of Si and B by pack cementation at 1000 °C in Ar, a conditioning anneal at 1400 °C is used to develop an outer borosilicate layer followed by an inner MoSi2 and Mo5Si3 layer. During both isothermal and cyclic oxidation after an initial mass loss during the first hours of exposure, a steady state is reached for times up to 1000 h at temperatures ranging from 800 to 1200 °C, demonstrating a significantly enhanced oxidation resistance.

Keywords

High-temperature materials Mo–Si–B–Ti alloys Pack cementation Oxidation-resistant coating 

Copyright information

© Springer Science+Business Media New York 2017

Authors and Affiliations

  1. 1.Institute for Applied MaterialsKarlsruhe Institute of Technology (KIT)KarlsruheGermany
  2. 2.Department of Materials Science and EngineeringUniversity of Wisconsin – MadisonMadisonUSA

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