eprintid: 10198905 rev_number: 10 eprint_status: archive userid: 699 dir: disk0/10/19/89/05 datestamp: 2024-10-25 08:35:23 lastmod: 2024-10-25 08:37:23 status_changed: 2024-10-25 08:35:23 type: article metadata_visibility: show sword_depositor: 699 creators_name: Zhang, Xiaolong creators_name: Liu, Chaozong creators_name: Wang, Shuo creators_name: Jiang, Yue creators_name: Chen, Hongyi creators_name: Zhang, Qingquan creators_name: Li, Qiang creators_name: Huang, Jie creators_name: Zhang, Zhihui title: Assessment of the mechanical and functional properties of nitinol alloys fabricated by laser powder bed fusion: Effect of strain rates ispublished: pub divisions: UCL divisions: B02 divisions: B04 divisions: C10 divisions: D16 divisions: F48 divisions: F45 divisions: G86 keywords: Strain rates; Nitinol SMAs; Laser powder bed fusion; Multi-scale characterization note: This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. abstract: Laser Powder Bed Fusion-fabricated (LPBFed) nitinol shape memory alloys (SMAs), which undergo solid-solid phase transitions between austenite and martensite, are increasingly utilized in various technical fields and are subjected to a wide range of strain rates during service. This study pioneers the investigation of a comprehensive range of strain rates (3.16 × 10−6-10°/s), encompassing the strain rates used in quasi-static tensile tests reported in the existing literature, to understand their effects on the deformation mechanisms of LPBFed nitinol SMAs. Utilizing multi-scale characterization, including macroscopic mechanical evaluation, mesoscale analysis of deformation surfaces, and microscale examination of microstructure, we reveal distinct deformation behaviors at different strain rates. At lower strain rates, the mechanical behavior exhibits little sensitivity to changes in the strain rates, with stress-induced martensite transformation or martensite detwinning and variant reorientation being the primary deformation mechanisms. However, at higher strain rates, we observe significant variability in mechanical response, dominated by dislocation-induced slip and reduced occurrence of stress-induced martensitic transformation. This study provides the first comprehensive database for the engineering applications of LPBFed Nitinol SMAs and offers critical insights into optimizing mechanical and functional assessments for these advanced materials. date: 2024-11 date_type: published publisher: Elsevier BV official_url: http://dx.doi.org/10.1016/j.msea.2024.147358 full_text_type: other language: eng verified: verified_manual elements_id: 2328184 doi: 10.1016/j.msea.2024.147358 lyricists_name: Chen, Hongyi lyricists_name: Huang, Jie lyricists_name: Liu, Chaozong lyricists_id: HCHEB60 lyricists_id: JHUAN03 lyricists_id: CLIUX47 actors_name: Liu, Chaozong actors_id: CLIUX47 actors_role: owner full_text_status: restricted publication: Materials Science and Engineering: A volume: 916 article_number: 147358 issn: 0921-5093 citation: Zhang, Xiaolong; Liu, Chaozong; Wang, Shuo; Jiang, Yue; Chen, Hongyi; Zhang, Qingquan; Li, Qiang; ... Zhang, Zhihui; + view all <#> Zhang, Xiaolong; Liu, Chaozong; Wang, Shuo; Jiang, Yue; Chen, Hongyi; Zhang, Qingquan; Li, Qiang; Huang, Jie; Zhang, Zhihui; - view fewer <#> (2024) Assessment of the mechanical and functional properties of nitinol alloys fabricated by laser powder bed fusion: Effect of strain rates. Materials Science and Engineering: A , 916 , Article 147358. 10.1016/j.msea.2024.147358 <https://doi.org/10.1016/j.msea.2024.147358>. document_url: https://discovery.ucl.ac.uk/id/eprint/10198905/1/Liu_IJMACTOOL-D-24-00452.pdf