Stability of vacancies in β-type Ti-15Mo-5Zr-3Al alloy fabricated via laser powder bed fusion

IF 4.2 Q2 ENGINEERING, MANUFACTURING

Additive manufacturing letters Pub Date : 2023-07-13 DOI:10.1016/j.addlet.2023.100162

Masataka Mizuno , Kazuki Sugita , Kousuke Do , Takuya Ishimoto , Takayoshi Nakano , Hideki Araki

{"title":"Stability of vacancies in β-type Ti-15Mo-5Zr-3Al alloy fabricated via laser powder bed fusion","authors":"Masataka Mizuno , Kazuki Sugita , Kousuke Do , Takuya Ishimoto , Takayoshi Nakano , Hideki Araki","doi":"10.1016/j.addlet.2023.100162","DOIUrl":null,"url":null,"abstract":"<div><p>The structural instability in the β-type titanium alloys could affect the stability of vacancies. The stability of vacancies in a β-type Ti-15Mo-5Zr-3Al alloy, fabricated via laser powder bed fusion (LPBF), was investigated using positron annihilation spectroscopy and first-principles calculations. The observed positron lifetimes were close to the experimental and calculated bulk lifetime of Ti-15Mo-5Zr-3Al, which indicates that vacancies were not detected in Ti-15Mo-5Zr-3Al by positron lifetime measurements. Therefore, for the first time, it has been confirmed that quenched-in vacancies are not introduced in the LPBF-manufactured β-type Ti-15Mo-5Zr-3Al despite the fast cooling rate in LPBF process. This feature is preferable for the structural stability in biomedical and industrial applications. The calculated atomic displacement from the ideal bcc lattice positions decreased in β-type Ti-Mo alloys with increasing Mo concentration, indicating that the bcc structure was stabilized by the added Mo. The calculated vacancy formation energies of Ti atoms in β-type Ti-14.5Mo and Ti-27.0Mo alloys exhibited an increasing trend with an increasing number of neighboring Mo atoms. Mo atoms also increased the migration energies of the neighboring paths of vacancies. The calculated results for Ti-15Mo-5Zr-3Al suggest that, while the bcc structure was stabilized by the Mo atoms in Ti-15Mo-5Zr-3Al, the migration and formation energies were still low enough for the diffusion of vacancies.</p></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"7 ","pages":"Article 100162"},"PeriodicalIF":4.2000,"publicationDate":"2023-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Additive manufacturing letters","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2772369023000439","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, MANUFACTURING","Score":null,"Total":0}

引用次数: 0

Abstract

The structural instability in the β-type titanium alloys could affect the stability of vacancies. The stability of vacancies in a β-type Ti-15Mo-5Zr-3Al alloy, fabricated via laser powder bed fusion (LPBF), was investigated using positron annihilation spectroscopy and first-principles calculations. The observed positron lifetimes were close to the experimental and calculated bulk lifetime of Ti-15Mo-5Zr-3Al, which indicates that vacancies were not detected in Ti-15Mo-5Zr-3Al by positron lifetime measurements. Therefore, for the first time, it has been confirmed that quenched-in vacancies are not introduced in the LPBF-manufactured β-type Ti-15Mo-5Zr-3Al despite the fast cooling rate in LPBF process. This feature is preferable for the structural stability in biomedical and industrial applications. The calculated atomic displacement from the ideal bcc lattice positions decreased in β-type Ti-Mo alloys with increasing Mo concentration, indicating that the bcc structure was stabilized by the added Mo. The calculated vacancy formation energies of Ti atoms in β-type Ti-14.5Mo and Ti-27.0Mo alloys exhibited an increasing trend with an increasing number of neighboring Mo atoms. Mo atoms also increased the migration energies of the neighboring paths of vacancies. The calculated results for Ti-15Mo-5Zr-3Al suggest that, while the bcc structure was stabilized by the Mo atoms in Ti-15Mo-5Zr-3Al, the migration and formation energies were still low enough for the diffusion of vacancies.

Abstract Image

查看原文本刊更多论文

激光粉末床熔合β型Ti-15Mo-5Zr-3Al合金中空位的稳定性

β型钛合金的结构不稳定性会影响空位的稳定性。利用正电子湮没谱和第一性原理计算研究了激光粉末床聚变（LPBF）制备的β型Ti-15Mo-5Zr-3Al合金中空位的稳定性。观察到的正电子寿命接近Ti-15Mo-5Zr-3Al的实验和计算体寿命，这表明通过正电子寿命测量在Ti-15Mo-54Zr-3Al中没有检测到空位。因此，首次证实，尽管在LPBF工艺中冷却速度很快，但在LPBF制造的β型Ti-15Mo-5Zr-3Al中没有引入空位淬火。该特征对于生物医学和工业应用中的结构稳定性是优选的。β型Ti-Mo合金中理想bcc晶格位置的原子位移随着Mo浓度的增加而减少，表明添加Mo使bcc结构稳定。β型Ti-14.5Mo和Ti-27.0Mo合金中Ti原子的空位形成能随着相邻Mo原子数的增加而呈增加趋势。Mo原子还增加了空位相邻路径的迁移能。Ti-15Mo-5Zr-3Al的计算结果表明，尽管Ti-15Mo-54Zr-3Al中的Mo原子稳定了bcc结构，但迁移能和形成能仍然足够低，足以使空位扩散。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊