Additive manufacturing of Ni-based superalloys: The outstanding issues

Research output: Contribution to journalReview articlepeer-review

Authors

Colleges, School and Institutes

External organisations

  • School of Metallurgy and Materials, University of Birmingham

Abstract

There is increasing interest in the use of additive manufacturing (AM) for Ni-based superalloys due to their various applications in the aerospace and power-generation sectors. Ni-based superalloys are known to have a complex chemistry, with over a dozen alloying elements in most alloys, enabling them to achieve outstanding high-temperature mechanical performance as well as oxidation resistance when processed using conventional routes (e.g., casting and forging). Nonetheless, this complex chemistry results in the formation of various phases that could affect their processability using AM, resulting in cracking. Furthermore, due to the directional solidification and rapid cooling associated with AM processes, the alloys experience significant anisotropy due to the epitaxially grown microstructure, as well as the residual stresses that can sometimes be difficult to mitigate using thermal postprocessing techniques. This article highlights the outstanding issues in Ni-based superalloys AM processing, with special emphasis on defect formation mechanisms, process optimization, and residual stress development.

Details

Original languageEnglish
Pages (from-to)758-764
Number of pages7
JournalMRS bulletin
Volume41
Issue number10
Early online date10 Oct 2016
Publication statusE-pub ahead of print - 10 Oct 2016

Keywords

  • metal, microstructure, Ni, texture