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Zyguła K, Wojtaszek M. Processing and Characterization of β Titanium Alloy Composite Using Power Metallurgy Approach. Materials (Basel) 2022; 15:5800. [PMID: 36079182 PMCID: PMC9457331 DOI: 10.3390/ma15175800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 08/16/2022] [Accepted: 08/17/2022] [Indexed: 06/15/2023]
Abstract
The β titanium alloy matrix composite was made from a mixture of elemental metal powders, including boron carbide. During the high-temperature sintering process, in situ synthesis took place as a result of the TiB and TiC reinforcing phases formed. The identification of these phases was confirmed by X-ray diffraction and microstructural analyses. The presence of unreacted B4C particles and the surrounding reaction layers allowed for the evaluation of diffusion kinetics of alloying elements using SEM and EDS analyses. The direction of diffusion of the alloying elements in the multicomponent titanium alloy and their influence on the in situ synthesis reaction taking place were determined. In addition, the relationship between the microstructural components, strengthening phases, and hardness was also determined. It was shown that in situ reinforcement of titanium alloy produced from a mixture of elemental powders with complex chemical composition is possible under the proposed conditions. Thus, it has been demonstrated that sufficiently high temperature and adequate holding time allows one to understand the kinetics of the synthesis of the strengthening phases, which have been shown to be controlled by the concentrations of alloying elements.
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Chen Y, Ortiz Rios C, McLain B, Newkirk JW, Liou F. TiNi-Based Bi-Metallic Shape-Memory Alloy by Laser-Directed Energy Deposition. Materials (Basel) 2022; 15:ma15113945. [PMID: 35683242 PMCID: PMC9182429 DOI: 10.3390/ma15113945] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 05/24/2022] [Accepted: 05/27/2022] [Indexed: 11/27/2022]
Abstract
In this study, laser-directed energy deposition was applied to build a Ti-rich ternary Ti–Ni–Cu shape-memory alloy onto a TiNi shape-memory alloy substrate to realize the joining of the multifunctional bi-metallic shape-memory alloy structure. The cost-effective Ti, Ni, and Cu elemental powder blend was used for raw materials. Various material characterization approaches were applied to reveal different material properties in two sections. The as-fabricated Ti–Ni–Cu alloy microstructure has the TiNi phase as the matrix with Ti2Ni secondary precipitates. The hardness shows no high values indicating that the major phase is not hard intermetallics. A bonding strength of 569.1 MPa was obtained by tensile testing, and digital image correlation reveals the different tensile responses of the two sections. Differential scanning calorimetry was used to measure the phase-transformation temperatures. The austenite finishing temperature of higher than 80 °C was measured for the Ti–Ni–Cu alloy section. For the TiNi substrate, the austenite finishing temperature was tested to be near 47 °C at the bottom and around 22 °C at the upper substrate region, which is due to the repeated laser scanning that acts as annealing on the substrate. Finally, the multiple shape-memory effect of two shape-memory alloy sides was tested and identified.
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Affiliation(s)
- Yitao Chen
- Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology, Rolla, MO 65409, USA; (B.M.); (F.L.)
- Correspondence:
| | - Cesar Ortiz Rios
- Department of Materials Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409, USA; (C.O.R.); (J.W.N.)
| | - Braden McLain
- Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology, Rolla, MO 65409, USA; (B.M.); (F.L.)
| | - Joseph W. Newkirk
- Department of Materials Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409, USA; (C.O.R.); (J.W.N.)
| | - Frank Liou
- Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology, Rolla, MO 65409, USA; (B.M.); (F.L.)
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Chmielewska A, Wysocki B, Kwaśniak P, Kruszewski MJ, Michalski B, Zielińska A, Adamczyk-Cieślak B, Krawczyńska A, Buhagiar J, Święszkowski W. Heat Treatment of NiTi Alloys Fabricated Using Laser Powder Bed Fusion (LPBF) from Elementally Blended Powders. Materials (Basel) 2022; 15:ma15093304. [PMID: 35591638 PMCID: PMC9104238 DOI: 10.3390/ma15093304] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 04/20/2022] [Accepted: 04/26/2022] [Indexed: 12/04/2022]
Abstract
The use of elemental metallic powders and in situ alloying in additive manufacturing (AM) is of industrial relevance as it offers the required flexibility to tailor the batch powder composition. This solution has been applied to the AM manufacturing of nickel-titanium (NiTi) shape memory alloy components. In this work, we show that laser powder bed fusion (LPBF) can be used to create a Ni55.7Ti44.3 alloyed component, but that the chemical composition of the build has a large heterogeneity. To solve this problem three different annealing heat treatments were designed, and the resulting porosity, microstructural homogeneity, and phase formation was investigated. The heat treatments were found to improve the alloy’s chemical and phase homogeneity, but the brittle NiTi2 phase was found to be stabilized by the 0.54 wt.% of oxygen present in all fabricated samples. As a consequence, a Ni2Ti4O phase was formed and was confirmed by transmission electron microscopy (TEM) observation. This study showed that pore formation in in situ alloyed NiTi can be controlled via heat treatment. Moreover, we have shown that the two-step heat treatment is a promising method to homogenise the chemical and phase composition of in situ alloyed NiTi powder fabricated by LPBF.
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Affiliation(s)
- Agnieszka Chmielewska
- Faculty of Material Science and Engineering, Warsaw University of Technology, Woloska 141 Str., 02-507 Warsaw, Poland; (M.J.K.); (B.M.); (A.Z.); (B.A.-C.); (A.K.)
- Correspondence: (A.C.); (W.Ś.)
| | - Bartłomiej Wysocki
- Centre of Digital Science and Technology, Cardinal Stefan Wyszynski University in Warsaw, Woycickiego 1/3, 01-938 Warsaw, Poland; (B.W.); (P.K.)
| | - Piotr Kwaśniak
- Centre of Digital Science and Technology, Cardinal Stefan Wyszynski University in Warsaw, Woycickiego 1/3, 01-938 Warsaw, Poland; (B.W.); (P.K.)
| | - Mirosław Jakub Kruszewski
- Faculty of Material Science and Engineering, Warsaw University of Technology, Woloska 141 Str., 02-507 Warsaw, Poland; (M.J.K.); (B.M.); (A.Z.); (B.A.-C.); (A.K.)
| | - Bartosz Michalski
- Faculty of Material Science and Engineering, Warsaw University of Technology, Woloska 141 Str., 02-507 Warsaw, Poland; (M.J.K.); (B.M.); (A.Z.); (B.A.-C.); (A.K.)
| | - Aleksandra Zielińska
- Faculty of Material Science and Engineering, Warsaw University of Technology, Woloska 141 Str., 02-507 Warsaw, Poland; (M.J.K.); (B.M.); (A.Z.); (B.A.-C.); (A.K.)
| | - Bogusława Adamczyk-Cieślak
- Faculty of Material Science and Engineering, Warsaw University of Technology, Woloska 141 Str., 02-507 Warsaw, Poland; (M.J.K.); (B.M.); (A.Z.); (B.A.-C.); (A.K.)
| | - Agnieszka Krawczyńska
- Faculty of Material Science and Engineering, Warsaw University of Technology, Woloska 141 Str., 02-507 Warsaw, Poland; (M.J.K.); (B.M.); (A.Z.); (B.A.-C.); (A.K.)
| | - Joseph Buhagiar
- Department of Metallurgy and Materials Engineering, University of Malta, MSD 2080 Msida, Malta;
| | - Wojciech Święszkowski
- Faculty of Material Science and Engineering, Warsaw University of Technology, Woloska 141 Str., 02-507 Warsaw, Poland; (M.J.K.); (B.M.); (A.Z.); (B.A.-C.); (A.K.)
- Correspondence: (A.C.); (W.Ś.)
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