# Creep deformation mechanism of LPBFed near α, and near β-Ti alloys

https://mdr.nims.go.jp/datasets/966d3970-f9d2-4683-bc80-866ed01092bf

## File

- [20251013MRS2026Abstract-Mitarai.docx](https://mdr.nims.go.jp/filesets/18d94ea0-66ca-40eb-b631-16d3f80e5946/download) ([Detail](https://mdr.nims.go.jp/filesets/18d94ea0-66ca-40eb-b631-16d3f80e5946.md))

## Id

966d3970-f9d2-4683-bc80-866ed01092bf

## Local identifier



## Visibility

open_to_public

## State

published

## Created at

2026-05-13T01:49:28.254182Z

## Updated at

2026-05-13T02:42:27.196210Z

## Published at

2026-05-13T05:27:30.742349Z

## Doi

https://doi.org/10.48505/nims.6289

## First published url



## Date published



## Recorded date published



## Resource type

conference_presentation

## Manuscript type

authors_original

## Collection



## Title

- title: Creep deformation mechanism of LPBFed near α, and near β-Ti alloys
  title_type: original
  lang: en

## Description

- description: "The laser powder bed fusion (LPBF) was applied for near α and near
    β - Ti alloys to investigate microstructure evolution depending on scanning conditions
    and creep deformation behavior related with microstructure. The melting pool boundaries
    that are formed by cyclic heating due to cyclic scanning of the laser beam were
    clearly observed in the as-built state in both alloys. The crystallographic orientation
    of the β phase was random in near α -Ti alloys, while columnar microstructures
    with crystallographic lamellar-like microstructure, a near single crystal-like
    microstructure, and polycrystalline structures were observed under the specific
    scanning condition in near β -Ti alloys. The martensite transformation from the
    β to α phase occurred during rapid cooling during LPBF. The fine martensitic a
    phase was formed inside the melting pool. In near α Ti-Alloy, a fine α phase formed
    with decrease of energy density, VED, while in near β -Ti alloy, the opposite
    behavior was observed; that is, a fine α phase formed at higher VED.\r\nThe creep
    deformation mechanism is dislocation creep, which depends on mainly the microstructure
    in the molten pool rather than the grain size in both alloys. Creep lives of LPBFed
    near α -Ti alloy were between those of the forged sample with bimodal structure
    and with lamellar structure. It was also found that the Hot Isostatic Press is
    helpful for improving creep life by eliminating micro-defects. In near β -Ti alloy,
    the creep strain was larger at low stress in the LPBFed samples compared with
    the forged sample, but the creep life was slightly longer in the LPBFed samples
    than in the forged sample. In addition, a creep rupture surface was observed at
    the melt-pool boundary, suggesting that the α phase, which continuously forms
    on the melt-pool boundary in near β -Ti alloy, is the crack formation site."
  description_type: abstract
  lang: eng

## Creator

- name: Yoko Yamabe-Mitarai
  role: author
  organization: Department of Advanced Material Science, Graduate School of Frontier
    Sciences, The University of Tokyo
- name: Yoshiaki Toda
  role: author
  orcid: https://orcid.org/0000-0002-8343-2890
  organization: National Institute for Materials Science
  department: Center for Basic Research on Materials/Data-driven Materials Research
    Field/Materials Modeling Group
- name: Tetsuya Matsunaga
  role: author
  organization: JAXA
- name: Ryosuke Ozasa(
  role: author
  organization: Graduate School of Engineering, Osaka University
- name: Takuya Ishimoto
  role: author
  organization: University of Toyama
- name: Tsutomu Ito
  role: author
  organization: Toyama Prefectural University
- name: Takayoshi Nakano
  role: author
  organization: Graduate School of Engineering, Osaka University

## Contact agent



## Publisher



## Managing organization



## Keyword

- subject: Ti-6Al-4Nb-4Zr
  schema: not_defined
- subject: Ti-6Al-2Sn-4Zr-6Mo
  schema: not_defined
- subject: Laser powder bed fusion
  schema: not_defined
- subject: Alpha formation
  schema: not_defined
- subject: Creep strength
  schema: not_defined
- subject: Volume energy density
  schema: not_defined
- subject: Crystallographic orientation
  schema: not_defined

## Rights

- identifier: http://rightsstatements.org/vocab/InC/1.0/

## Other identifier(s)



## Data origin

- data_origin_type: other

## Embargo



## Journal



## Conference

name: 2026 Materials Research Society Spring Meeting & Exhibit
start_date: 2026-04-26
end_date: 2026-05-01
identifier: https://www.mrs.org/meetings-events/annual-meetings/2026-mrs-spring-meeting-exhibit

## Related item



## Funding

- identifier: JP21H05198
  funder_name: JSPS
  description: Science for Creation of Super-Titanium by Super Thermal Field

## Instrument



## Instrument operator



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## Measurement method



## Specimen



## Chemical composition



## Structure for specimen



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## Computational method



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## Fileset

- id: 18d94ea0-66ca-40eb-b631-16d3f80e5946
  filename: 20251013MRS2026Abstract-Mitarai.docx
  content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
  size: 16357
  md5: 7e5a044d6818202d6346c23d669a5ffe

## Thumbnail

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filename: 20251013MRS2026Abstract-Mitarai.docx