Comprehensive study on the formation of grain boundary serrations in additively manufactured Haynes 230 alloy
Research output: Contribution to journal › Research article › Contributed › peer-review
Contributors
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
Original language | English |
---|---|
Article number | 110092 |
Journal | Materials characterization |
Volume | 160 |
Publication status | Published - Feb 2020 |
Peer-reviewed | Yes |
External IDs
Scopus | 85077398171 |
---|
Keywords
Keywords
- Additive manufacturing, EBSD, Grain boundary serration, Haynes 230, Laser metal deposition, Superalloy