Comprehensive study on the formation of grain boundary serrations in additively manufactured Haynes 230 alloy

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Beitragende

  • Maximilian Haack - , Fraunhofer-Institut für Werkstoff- und Strahltechnik (Autor:in)
  • Martin Kuczyk - , Fraunhofer-Institut für Werkstoff- und Strahltechnik (Autor:in)
  • André Seidel - , Fraunhofer-Institut für Werkstoff- und Strahltechnik (Autor:in)
  • Elena López - , Fraunhofer-Institut für Werkstoff- und Strahltechnik (Autor:in)
  • Frank Brueckner - , Institut für Werkstoffwissenschaft (IfWW), Fraunhofer-Institut für Werkstoff- und Strahltechnik (Autor:in)
  • Christoph Leyens - , Professur für Werkstofftechnik, Fraunhofer-Institut für Werkstoff- und Strahltechnik (Autor:in)

Abstract

Recently, grain boundary serrations have been introduced in conventionally processed Haynes 230 through a slow-cooling heat treatment. The aim of this work was to utilize these heat treatments to introduce serrations in additively manufactured (Laser Metal Deposition) Haynes 230. Contrary to expectations, serrations already formed during the fast-cooling of the Laser Metal Deposition process. Electron Backscatter Diffraction was used to elucidate the underlying phenomenon for the emergence of serrations during fast-cooling. As a result, a hypothesis regarding a new mechanism responsible for the formation of grain boundary serrations was formulated. Additionally, specific characteristics of the Laser Metal Deposition process have been identified. This includes a columnar-to-equiaxed transition (CET) for slower feed rates, leading to smaller grains despite lower cooling rates; the observation of an abrupt increase in grain growth for a raised solution annealing temperature; the fact that serrations hinder uncontrolled grain growth and finally that the LMD-process leads to a finer carbide morphology compared to conventional manufacturing methods, potentially leading to an increased precipitation strengthening effect.

Details

OriginalspracheEnglisch
Aufsatznummer110092
FachzeitschriftMaterials characterization
Jahrgang160
PublikationsstatusVeröffentlicht - Feb. 2020
Peer-Review-StatusJa

Externe IDs

Scopus 85077398171

Schlagworte

Schlagwörter

  • Additive manufacturing, EBSD, Grain boundary serration, Haynes 230, Laser metal deposition, Superalloy