Thermokinetics driven microstructure and phase evolution in laser-based additive manufacturing of Ti-25wt.%Nb and its performance in physiological solution
{"title":"Thermokinetics driven microstructure and phase evolution in laser-based additive manufacturing of Ti-25wt.%Nb and its performance in physiological solution","authors":"Selvamurugan Palaniappan , K.V. Mani Krishna , Madhavan Radhakrishnan , Shashank Sharma , Mohan Sai Ramalingam , Rajarshi Banerjee , Narendra B. Dahotre","doi":"10.1016/j.mtla.2024.102190","DOIUrl":null,"url":null,"abstract":"<div><p>A bio-compatible Ti-25 wt% Nb alloy fabricated from a blend of pure elemental powders using laser powder bed fusion additive manufacturing technique. The present work investigated the effects of processing conditions on the evolution of microstructures and its consequential material attributes, such as mechanical properties and corrosion performance. Thermal management strategies comprising laser powers of 200 W and 300 W in complement with a shorter scan length (1 mm) and substrate preheating above <span><math><mi>β</mi></math></span>-transus temperature (1123 K) were considered to achieve complete dissolution of niobium particles. The microstructure in the 200 W sample showed thin <span><math><mrow><mi>α</mi><mi>”</mi></mrow></math></span> martensite needles in <span><math><mi>β</mi></math></span> matrix while martensite laths in the 300 W condition appear coarse and were twice the area fraction compared to that in 200 W build. On the other hand, microstructures in the heated substrate sample exhibited the evolution of <span><math><mi>α</mi></math></span> and <span><math><mi>β</mi></math></span> phases. A multi-scale finite element method based thermo-kinetic model spanning from melt pool scale to the component scale was incorporated to understand the mechanism of the evolution of microstructures during liquid–solid and solid–solid state transformation. Electrochemical performance in the simulated body fluid of the printed alloys was found to be significantly affected by the presence of martensite fractions. Both mechanical and corrosion behaviors were favorably influenced by adoption of the substrate preheating during additive manufacturing due to promotion of diffusional transformation of <span><math><mi>β</mi></math></span> to <span><math><mi>α</mi></math></span> transformation at the expense of martensitic transformation.</p></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"37 ","pages":"Article 102190"},"PeriodicalIF":3.0000,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Materialia","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S258915292400187X","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
A bio-compatible Ti-25 wt% Nb alloy fabricated from a blend of pure elemental powders using laser powder bed fusion additive manufacturing technique. The present work investigated the effects of processing conditions on the evolution of microstructures and its consequential material attributes, such as mechanical properties and corrosion performance. Thermal management strategies comprising laser powers of 200 W and 300 W in complement with a shorter scan length (1 mm) and substrate preheating above -transus temperature (1123 K) were considered to achieve complete dissolution of niobium particles. The microstructure in the 200 W sample showed thin martensite needles in matrix while martensite laths in the 300 W condition appear coarse and were twice the area fraction compared to that in 200 W build. On the other hand, microstructures in the heated substrate sample exhibited the evolution of and phases. A multi-scale finite element method based thermo-kinetic model spanning from melt pool scale to the component scale was incorporated to understand the mechanism of the evolution of microstructures during liquid–solid and solid–solid state transformation. Electrochemical performance in the simulated body fluid of the printed alloys was found to be significantly affected by the presence of martensite fractions. Both mechanical and corrosion behaviors were favorably influenced by adoption of the substrate preheating during additive manufacturing due to promotion of diffusional transformation of to transformation at the expense of martensitic transformation.
利用激光粉末床熔融增材制造技术,从纯元素粉末混合物中制造出生物相容性钛-25 wt% Nb 合金。本研究调查了加工条件对微结构演变的影响,以及由此产生的材料属性,如机械性能和腐蚀性能。为实现铌颗粒的完全溶解,考虑了热管理策略,包括 200 W 和 300 W 的激光功率以及较短的扫描长度(1 mm)和高于 β 传递温度(1123 K)的基底预热。200 W 试样的微观结构显示,在 β 基体中存在细长的 α "马氏体针状结构,而 300 W 条件下的马氏体板条则显得较粗,其面积分数是 200 W 条件下的两倍。另一方面,加热基体样品的微观结构表现出 α 和 β 相的演变。为了了解液-固和固-固状态转变过程中微结构的演变机制,我们采用了基于多尺度有限元法的热动力学模型,该模型涵盖了从熔池尺度到元件尺度。研究发现,印刷合金在模拟体液中的电化学性能会受到马氏体组分的显著影响。在增材制造过程中采用基底预热,可促进β向α转变的扩散转变,从而以马氏体转变为代价,这对机械和腐蚀行为都产生了有利影响。
期刊介绍:
Materialia is a multidisciplinary journal of materials science and engineering that publishes original peer-reviewed research articles. Articles in Materialia advance the understanding of the relationship between processing, structure, property, and function of materials.
Materialia publishes full-length research articles, review articles, and letters (short communications). In addition to receiving direct submissions, Materialia also accepts transfers from Acta Materialia, Inc. partner journals. Materialia offers authors the choice to publish on an open access model (with author fee), or on a subscription model (with no author fee).