A novel spark plasma sintering route to process high-strength Ti–4Al–2Fe/TiB nano-composite
TL;DR: In this article, a spark plasma sintering route was used to process the Ti-4Al-2Fe alloy and a nano-composite, which exhibited excellent mechanical properties (CS'='1798 MPa', compressive strength (2414 MPa), and elastic modulus (140 GPa).
Abstract: Ti–4Al–2Fe alloy and Ti–4Al–2Fe/TiB nano-composite were processed by a novel spark plasma sintering route. KBF4 was used as an alternative and inexpensive boron precursor to form TiB reinforcement in situ during sintering. Fe was used as an alternative to vanadium to make the (α + β) Ti matrix. The processed Ti–4Al–2Fe alloy exhibited excellent mechanical properties (CS = 1798 MPa). The TiB whiskers were distributed homogeneously and were fine (widths 130 nm and lengths from 100 nm to 3 µm). No residual TiB2 was found in the composite, in contrast with other methods. The TiB homogenised and refined the microstructure, while the hardness (710 HV), compressive strength (2414 MPa) and elastic modulus (140 GPa) all increased significantly when compared to the unreinforced alloy.
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TL;DR: In this article, the effect of sintering temperatures and Fe content on the mechanical properties of alloys was studied. But the results showed that the Fe content is excessive in Ti-15Nb-25Zr-8Fe, which leads to some disadvantages including intermetallic compounds formation and grain boundary coarsening.
Abstract: Ti-15Nb-25Zr-(0, 4, 8)Fe (mol.%) alloys were prepared via spark plasma sintering (SPS) for 10 min at 800, 1000, and 1200 °C to study the effect of sintering temperatures and Fe content on the mechanical properties of alloys. The main phase of the alloys sintered at 800 °C is α phase. When the temperature is increased to 1000 and 1200 °C, the alloys are mainly β phase. Raising the sintering temperature can promote the diffusion of elements. Therefore, high strength and high plasticity are obtained in the alloys sintered at high temperature. The compressive strength of Ti-15Nb-25Zr sintered at 1200 °C is 1604 MPa, and the fracture strain is around 35%. The strength and plasticity are influenced by the complex effects of elemental diffusion, grain boundary and solid-solution strengthening. Adding Fe can improve the diffusion of elements, promote the formation of β grains and supply solid-solution strengthening effect. As the sintering temperature is increased, the compressive strength of Ti-15Nb-25Zr-4Fe shows an increasing trend and the plasticity is almost not changed. The Fe content is excessive in Ti-15Nb-25Zr-8Fe, which leads to some disadvantages including intermetallic compounds formation and grain boundary coarsening. The mechanical properties of Ti-15Nb-25Zr-8Fe are not always better than those of Ti-15Nb-25Zr-4Fe. The compressive strength of Ti-15Nb-25Zr-8Fe shows an increasing trend and the plasticity firstly increases and then decreases when the temperature is raised from 800 up to 1200 °C. Although the sintering time of SPS is short, Ti-15Nb-25Zr-(4, 8)Fe sintered at 1000 °C and Ti-15Nb-25Zr-(0, 4)Fe sintered at 1200 °C show good combination of strength and plasticity.
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TL;DR: In this article , the state of the art on metal matrix composites (MMCs), including cermets, obtained in situ by powder metallurgy, is reviewed, and key aspects related to the development of such materials in order to establish theoretical criteria for decision making before and along experiments.
Abstract: In situ composite manufacture is an approach to improve interfacial adhesion between matrix and reinforcements, in which reinforcements are synthesized along composite processing itself. In situ powder metallurgy route, in particular, offers alternatives to some shortcomings found in other techniques. This work aims not only to review the state of the art on metal matrix composites (MMCs)—including cermets—obtained in situ by powder metallurgy, but also to dissect key aspects related to the development of such materials in order to establish theoretical criteria for decision making before and along experiments. Aspects regarding the design, raw material selection, and processing of such composites were observed and divided between concept, intrinsic, and extrinsic parameters. That way, by means of material databases and computational thermodynamics applied to examples of the reviewed literature, we aim at providing tools in both conducting leaner experiments and richer discussion in this field.
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Book•
01 Jan 2001
19,319 citations
"A novel spark plasma sintering rout..." refers background in this paper
...5% by analysing the XRD peaks in both the composite and the unreinforced alloy [24]....
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Book•
01 Jan 1956
TL;DR: In this article, the authors present a chemical analysis of X-ray diffraction by Xray Spectrometry and phase-diagram Determination of single crystal structures and phase diagrams.
Abstract: 1. Properties of X-rays. 2. Geometry of Crystals. 3. Diffraction I: Directions of Diffracted Beams. 4. Diffraction II: Intensities of Diffracted Beams. 5. Diffraction III: Non-Ideal Samples. 6. Laure Photographs. 7. Powder Photographs. 8. Diffractometer and Spectrometer. 9. Orientation and Quality of Single Crystals. 10. Structure of Polycrystalline Aggregates. 11. Determination of Crystal Structure. 12. Precise Parameter Measurements. 13. Phase-Diagram Determination. 14. Order-Disorder Transformation. 15. Chemical Analysis of X-ray Diffraction. 16. Chemical Analysis by X-ray Spectrometry. 17. Measurements of Residual Stress. 18. Polymers. 19. Small Angle Scatters. 20. Transmission Electron Microscope.
17,428 citations
28 Jan 2005
TL;DR: Peters et al. as discussed by the authors discussed the structure and properties of Titanium and Titanium Aluminides, and proposed a continuous fiber reinforced Titanium matrix composites (C.Leyens, et al.).
Abstract: Foreword.List of Contributors.1. Structure and Properties of Titanium and Titanium Alloys (M. Peters, et al.).2. Beta Titanium Alloys (G. Terlinde and G. Fischer).3. Orthorhombic Titanium Aluminides: Intermetallic with Improved Damage Tolerance (J. Kumpfert and C. Leyens).4. gamma-Titanium Aluminide Alloys: Alloy Design and Properties (F. Appel and M. Oehring).5. Fatigue of Titanium Alloys (L. Wagner and J.K. Bigoney).6. Oxidation and Protection of Titanium Alloys and Titanium Aluminides (C. Leyens).7. Titanium and Titanium Alloys - From Raw material to Semi-finished Products (H. Sibum).8. Fabrication of Titanium Alloys (M. Peters and C. Leyens).9. Investment Casting of Titanium (H.-P. Nicolai and Chr. Liesner).10. Superplastic Forming and Diffusion Bonding of Titanium and Titanium Alloys (W. Beck).11. Forging of Titanium (G. Terlinde, et al.).12. Continuous Fiber Reinforced Titanium matrix Composites: Fabrication, Properties and Applications (C. Leyens, et al.).13. Titanium Alloys for Aerospace Applications (M. Peters, et al.).14. Production, Processing and Application of gamma(TiAl)-Based Alloys (H. Kestler and H. Clemens).15. Non-Aerospace Applications of Titanium and Titanium Alloys (M. Peters and C. Leyens).16. Titanium and its Alloys for Medical Applications (J. Breme, et al.).17. Titanium in Dentistry (J. Lindigkeit).18. Titanium in Automotive Production (O. Schauerte).19. Offshore Applications for Titanium Alloys (L. Lunde and M. Seiersten).Subject Index.
2,278 citations
Additional excerpts
...Ti–6Al–4V is the most commonly used α–β alloy due to its attractive properties [1]....
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TL;DR: In this paper, microstructural properties of hot isostatically pressed Ti-6Al-4V alloy with 0, 0.05, 0., 10, and 0.40 wt.% B additions have been examined, with particular emphasis on identifying the micro-structural length scale (grain size vs. lath size) that controls the mechanical properties of these alloys.
357 citations
Additional excerpts
...7 140± 3a Ti–6Al–4Vb 350 [14,31] 850 [34] 1062 [34,35] 9 [34] 110 [38,33] Ti–6Al–4V/TiBb 440 [14] 1400 [34] 1600 [34] 6 [34] 136 [38]...
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25 Feb 2006-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this article, the effects of alloying elements, thermo-mechanical treatment and particle reinforcement on microstructures and mechanical properties of powder metallurgy (PM) Ti alloys and their composites were studied.
Abstract: Low cost and good performance are two major factors virtually important for Ti alloy development. In this paper, we have studied the effects of alloying elements, thermo-mechanical treatment and particle reinforcement on microstructures and mechanical properties of powder metallurgy (PM) Ti alloys and their composites. Our results indicate that low cost PM Ti alloys and their composites with attractive properties can be fabricated through a single compaction-sintering process, although secondary treatments are required for high performance applications. Three new PM Ti alloys and one TiC/Ti composite of high performance are developed, and new design principles are also proposed. For design of PM Ti alloys, addition of alloying elements has the beneficial effect of enhanced sintering and/or improved mechanical properties. For example, Fe element accelerates the sintering process, Mo and Al are good candidates for solution strengthening, and rare earth elements effectively increase the material ductility by scavenging oxygen from the Ti matrix. For the design of Ti-based composites, in situ formation of strengthening particles and solid solution hardening of the matrix both should be considered simultaneously for alloy development. Cr 3 C 2 is found to be a very suitable additive for processing particle reinforced Ti composites.
250 citations
"A novel spark plasma sintering rout..." refers background in this paper
...It has been reported that addition of Fe increases the yield strength of Ti [36]....
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