Effect of Ta and W Additions on Microstructure and Mechanical Properties of Tilt-Cast Ti-45Al-5Nb-2C Alloy

The effect of Ta and W additions on microstructure and mechanical properties of tilt-cast Ti-45Al-5Nb-2C (at.%) alloy was investigated. Three alloys with nominal composition Ti-45Al-5Nb-2C-2X (in at.%), where X is Ta or W, were prepared by vacuum induction melting in graphite crucibles followed by tilt casting into graphite moulds. The microstructure of the tilt-cast alloys consists of the α2(Ti3Al) + γ(TiAl) lamellar grains, single γ phase, (Ti,Nb,X)2AlC particles with a small amount of (Ti,Nb,X)C, and β/B2 phase identified only in W containing alloy. The EDS analysis shows that Ta segregates into the carbide particles and reduces dissolution of Nb in both (Ti,Nb,Ta)C and (Ti,Nb,Ta)2AlC phases. The alloying with W reduces Nb content in both carbide phases and leads to stabilisation of β/B2 phase in the lamellar α2 + γ regions. The alloying with Ta and W does not affect the volume fraction of the carbide particles but influences their size and morphology. While the alloying with Ta and W has no significant effect on Vickers hardness and the indentation elastic modulus of the studied alloys, the addition of Ta affects the nanohardness and elastic modulus of the (Ti,Nb,Ta)2AlC phase. The addition of W significantly increases the Vickers microhardness of the lamellar α2 + γ regions.

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Comparative Study of Microstructure and Mechanical Properties of Two TiAl-Based Alloys Reinforced with Carbide Particles

Molecules ◽

10.3390/molecules25153423 ◽

2020 ◽

Vol 25 (15) ◽

pp. 3423 ◽

Cited By ~ 1

Author(s):

Juraj Lapin ◽

Kateryna Kamyshnykova ◽

Alena Klimova

Keyword(s):

Mechanical Properties ◽

Volume Fraction ◽

Centrifugal Casting ◽

Interlamellar Spacing ◽

Vacuum Induction Melting ◽

Solid Solution Phase ◽

Nominal Composition ◽

Induction Melting ◽

Microstructure And Mechanical Properties ◽

Carbide Particles

Microstructure and mechanical properties of two TiAl-based alloys with nominal composition Ti-42.6Al-8.7Nb-0.3Ta-2.0C and Ti-41.0Al-8.7Nb-0.3Ta-3.6C (in at.%) were investigated and compared. The alloys were prepared by vacuum induction melting, followed by centrifugal casting. The as-cast samples were subjected to hot isostatic pressing and heat treatment consisting of solution annealing in β (Ti-based solid solution) phase field, cooling at a constant rate and stabilization annealing. The microstructure of the alloys consists of α2 (Ti3Al) + γ (TiAl) lamellar grains, single γ phase, coarse Ti2AlC particles, and irregular shaped α2 phase. The increase in the content of C at the expense of decreasing Al in the studied alloys affects solid-state phase transformation temperatures and leads to a decrease in size of grains and primary Ti2AlC particles, increase in the volume fraction of reinforcing carbide particles, decrease in the volume fraction of lamellar colonies, and widening of the grain boundaries. Long-term ageing at 800 °C has no effect on the grain size but leads to the formation of Ti4Al3Nb particles and increase in interlamellar spacing. The Vickers hardness, microhardness of lamellar grains, indentation nanohardness, and elastic modulus of the boundary γ phase decrease during ageing. The Ti-42.6Al-8.7Nb-0.3Ta-2.0C alloy shows improved creep resistance compared to that of Ti-41.0Al-8.7Nb-0.3Ta-3.6C and some reference TiAl-based alloys at a temperature of 800 °C and applied stress of 200 MPa.

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Microstructure and Mechanical Properties of Rapidly Solidified β-Type Ti–Fe–Sn–Mo Alloys with High Specific Strength and Low Elastic Modulus

Metals ◽

10.3390/met9111135 ◽

2019 ◽

Vol 9 (11) ◽

pp. 1135 ◽

Cited By ~ 1

Author(s):

Li ◽

Ma ◽

Jia ◽

Meng ◽

Tang ◽

...

Keyword(s):

Mechanical Properties ◽

Elastic Modulus ◽

Volume Fraction ◽

High Yield ◽

Specific Strength ◽

High Specific Strength ◽

Microstructure And Mechanical Properties ◽

Low Elastic Modulus ◽

Mo Content ◽

Rapidly Solidified

The microstructure and mechanical properties of rapidly solidified β-type Ti–Fe–Sn–Mo alloys with high specific strength and low elastic modulus were investigated. The results show that the phases of Ti–Fe–Sn–Mo alloys are composed of the β-Ti, α-Ti, and TiFe phases; the volume fraction of TiFe phase decreases with the increase of Mo content. The high Fe content results in the deposition of TiFe phase along the grain boundary of the Ti phase. The Ti75Fe19Sn5Mo1 alloy exhibits the high yield strength, maximum compressive strength, large plastic deformation, high specific strength, high Vickers hardness, and large toughness value, which is a superior new engineering material. The elastic modulus (42.1 GPa) of Ti75Fe15Sn5Mo5 alloy is very close to the elastic modulus of human bone (10–30 GPa), which indicating that the alloy can be used as a good biomedical alloy. In addition, the large H/Er and H3/Er2 values of Ti75Fe19Sn5Mo1 alloy indicate the good wear resistance and long service life as biomedical materials.

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The Influence of the Re-Melting Times on Microstructure and Mechanical Properties for Revert Alloy K452

Materials Science Forum ◽

10.4028/www.scientific.net/msf.747-748.715 ◽

2013 ◽

Vol 747-748 ◽

pp. 715-722 ◽

Cited By ~ 1

Author(s):

Chao Yuan ◽

Jian Ting Guo ◽

Chang Jiang Liu ◽

Jie Shan Hou ◽

Gu Song Li

Keyword(s):

Mechanical Properties ◽

Chemical Composition ◽

Gas Turbines ◽

Engineering Application ◽

Ceramic Foam ◽

Gas Content ◽

Vacuum Induction Melting ◽

Induction Melting ◽

Microstructure And Mechanical Properties ◽

Key Factor

The influence of the re-melting times on chemical composition, microstructure, and mechanical properties of revert alloy K452 were systemically investigated. It was shown that the key factor in the engineering application was the control of gas content and porosities level in revert alloy. By an advancing technology in combination with the superheat treatment, adding a small amount of alloying elements such as C, Al, Ti, and using ceramic foam filters during vacuum induction melting, the composition and mechanical properties of the revert alloy in addition of 50% scrap were similar to that in the virgin alloy, which has successfully been used in applications for nozzle vanes of some new gas turbines.

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The Effect of Ti, N and V Content and Heat Treatment on Irradiation and Mechanical Property of SCRAM Steels

Volume 6: Nuclear Education, Public Acceptance and Related Issues; Instrumentation and Controls (I&C); Fusion Engineering; Beyond Design Basis Events ◽

10.1115/icone22-30625 ◽

2014 ◽

Cited By ~ 1

Author(s):

Chi Yu ◽

Feng Yang ◽

Jinping Suo

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Transition Temperature ◽

Volume Fraction ◽

Vacuum Induction Melting ◽

Induction Melting ◽

Intermediate Heat Treatment ◽

Brittle Transition ◽

Ductile Brittle Transition Temperature ◽

Brittle Transition Temperature

An Fe-Cr-W-V-Ti-N steel named SCRAM (super-clean reduced-activation martensitic) steel was designed for the first wall and blanket structure of fusion power plants. Compared with the Fe-Cr-W-V-Ta steel, TiN can precipitate first at 1650°C rather than TaC by the Thermal-cal Calculation. And we take vacuum induction melting (VIM) and electro-slag re-melting (ESR) together to manufacture the SCRAM steel, which can make the TiN fine and the steel pure. Mechanical properties and microstructures of SCRAM steels irradiated with single-beam (Fe) and sequential-beam (Fe plus He and Fe plus H) at 300°C were studied. The results show that, SCRAM steel can have better mechanical properties before and after irradiation while Ti was doped into the SCRAM steel. It has been reported that the precipitation formed in the steel has effect on the mechanical properties, irradiation properties and the ductile brittle transition temperature (DBTT). The effect of intermediate heat treatment on precipitation behavior and mechanical properties of SCRAM steel was investigated in order to obtain dispersed fine M23C6 carbides. The results indicated that MX carbonitrides precipitated first in the steel with intermediate heat treatment at 870°C rather than M23C6, which led to a decrease of carbon concentration in the supersaturated martensitic matrix and correspondingly a reduced volume fraction and mean size of M23C6. The intermediate heat treatment was beneficial to the mechanical properties, and proposed for reduction on the ductile brittle transition temperature (DBTT).

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X-ray Computed Tomography Studies on Porosity Distribution in Vacuum Induction Cast Al-7Si Alloys

JOM ◽

10.1007/s11837-021-04944-z ◽

2021 ◽

Author(s):

James Mathew ◽

Mark A. Williams ◽

Prakash Srirangam

Keyword(s):

Computed Tomography ◽

Mechanical Properties ◽

Aluminum Alloys ◽

Volume Fraction ◽

3D Visualization ◽

Vacuum Induction Melting ◽

Induction Melting ◽

Muffle Furnace ◽

X Ray ◽

X Ray Computed

AbstractPorosity in aluminum alloys is a great concern to the casting and automotive industry. In this publication, porosity formation in air-melted and vacuum induction melted (VIM) aluminum alloys was studied and compared to understand its effect on microstructure and mechanical properties of Al-7Si alloys. Al-7Si alloys were cast at 700°C and 900°C in a muffle furnace and VIM furnace. Microstructural results show that the alloys cast in muffle furnace refined the eutectic silicon compared with the cast samples prepared in VIM furnace. X-ray computed tomography (XCT) was used for three-dimensional (3D) visualization and quantification of porosity in these alloys. The volume fraction of pores was observed to be higher in alloy air-melted at 900°C compared with 700°C. XCT results from VIM alloy samples showed no significant porosity when cast at either 700°C or 900°C. The morphology of large pores in alloys air-melted at 700°C represents the formation of shrinkage porosity due to the incomplete flow of molten metal during solidification. Tensile test results show that the elongation property of VIM alloy was increased by more than 20% compared with air-melted alloy. The tensile strength and elongation were observed to be higher for alloy samples cast at 700°C compared with 900°C for both air-melted and VIM alloys. The findings from microstructure, XCT, and tensile tests show that vacuum induction melting improves the mechanical properties of the alloy compared with air-melted alloy.

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Effect of Titanium Carbide Particles on Mechanical Properties of Aluminum Matrix Composites

Wasit Journal of Engineering Sciences ◽

10.31185/ejuow.vol5.iss2.55 ◽

2017 ◽

Vol 5 (2) ◽

pp. 20-30

Author(s):

Zaman Khalil Ibrahim

Keyword(s):

Mechanical Properties ◽

Titanium Carbide ◽

Compression Strength ◽

Volume Fraction ◽

Aluminum Matrix ◽

Aluminum Matrix Composites ◽

Matrix Composites ◽

Powder Metallurgy Technique ◽

Carbide Particles ◽

Properties Of Composites

In this research aluminum matrix composites (AMCs) was reinforced by titanium carbide (TiC) particles and was produced. Powder metallurgy technique (PM) has been used to fabricate AMCs reinforced with various amounts (0%, 4%, 8%, 12%, 16% and 20% volume fraction) of TiC particles to study the effect of different volume fractions on mechanical properties of the Al-TiC composites. Measurements of compression strength and hardness showed that mechanical properties of composites increased with an increase in volume fraction of TiC Particles. Al-20 % vol. TiC composites exhibited the best properties with hardness value (97HRB) and compression strength value (275Mpa).

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The Effect of Quenching and Partitioning (Q&P) Heat Treatment on the Microstructure and Mechanical Properties of High Boron Steel

Materials ◽

10.3390/ma14061556 ◽

2021 ◽

Vol 14 (6) ◽

pp. 1556

Author(s):

Zhao Li ◽

Run Wu ◽

Mingwei Li ◽

Song-Sheng Zeng ◽

Yu Wang ◽

...

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Volume Fraction ◽

Martensitic Steel ◽

Boron Steel ◽

Quenching And Partitioning ◽

Effect Mechanism ◽

Microstructure And Mechanical Properties ◽

High Boron ◽

Cast Condition

High boron steel is prone to brittle failure due to the boride distributed in it with net-like or fishbone morphology, which limit its applications. The Quenching and Partitioning (Q&P) heat treatment is a promising process to produce martensitic steel with excellent mechanical properties, especially high toughness by increasing the volume fraction of retained austensite (RA) in the martensitic matrix. In this work, the Q&P heat treatment is used to improve the inherent defect of insufficient toughness of high boron steel, and the effect mechanism of this process on microstructure transformation and the change of mechanical properties of the steel has also been investigated. The high boron steel as-casted is composed of martensite, retained austensite (RA) and eutectic borides. A proper quenching and partitioning heat treatment leads to a significant change of the microstructure and mechanical properties of the steel. The net-like and fishbone-like boride is partially broken and spheroidized. The volume fraction of RA increases from 10% in the as-cast condition to 19%, and its morphology also changes from blocky to film-like. Although the macro-hardness has slightly reduced, the toughness is significantly increased up to 7.5 J·cm−2, and the wear resistance is also improved.

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Microstructure and Mechanical Properties of 14Cr-ODS Steels with Zr Addition

High Temperature Materials and Processes ◽

10.1515/htmp-2018-0067 ◽

2019 ◽

Vol 38 (2019) ◽

pp. 404-410 ◽

Cited By ~ 4

Author(s):

Weijuan Li ◽

Haijian Xu ◽

Xiaochun Sha ◽

Jingsong Meng ◽

Zhaodong Wang

Keyword(s):

Mechanical Properties ◽

Hot Isostatic Pressing ◽

Oxide Dispersion Strengthened ◽

Nominal Composition ◽

Ods Steel ◽

Zr Addition ◽

Microstructure And Mechanical Properties ◽

The Matrix ◽

Ods Steels ◽

The Impact

AbstractIn this study, oxide dispersion strengthened (ODS) ferritic steels with nominal composition of Fe–14Cr–2W–0.35Y2O3 (14Cr non Zr-ODS) and Fe–14Cr–2W–0.3Zr–0.35Y2O3 (14Cr–Zr-ODS) were fabricated by mechanical alloying (MA) and hot isostatic pressing (HIP) technique to explore the impact of Zr addition on the microstructure and mechanical properties of 14Cr-ODS steels. Microstructure characterization revealed that Zr addition led to the formation of finer oxides, which was identified as Y4Zr3O12, with denser dispersion in the matrix. The ultimate tensile strength (UTS) of the non Zr-ODS steel is about 1201 MPa, but UTS of the Zr-ODS steel increases to1372 MPa, indicating the enhancement of mechanical properties by Zr addition.

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Effect of Graphene Nanosheets Content on Microstructure and Mechanical Properties of Titanium Matrix Composite Produced by Cold Pressing and Sintering

Nanomaterials ◽

10.3390/nano8121024 ◽

2018 ◽

Vol 8 (12) ◽

pp. 1024 ◽

Cited By ~ 7

Author(s):

Milad Haghighi ◽

Mohammad Shaeri ◽

Arman Sedghi ◽

Faramarz Djavanroodi

Keyword(s):

Mechanical Properties ◽

Matrix Composite ◽

Volume Fraction ◽

Graphene Nanosheets ◽

Microstructural Analysis ◽

Titanium Matrix ◽

Titanium Matrix Composite ◽

Cold Pressing ◽

Sintering Time ◽

Microstructure And Mechanical Properties

The effect of graphene nanosheet (GNS) reinforcement on the microstructure and mechanical properties of the titanium matrix composite has been discussed. For this purpose, composites with various GNS contents were prepared by cold pressing and sintering at various time periods. Density calculation by Archimedes’ principle revealed that Ti/GNSs composites with reasonable high density (more than 99.5% of theoretical density) were produced after sintering for 5 h. Microstructural analysis by X-ray diffraction (XRD) and a field emission scanning electron microscope (FESEM) showed that TiC particles were formed in the matrix during the sintering process as a result of a titanium reaction with carbon. Higher GNS content as well as sintering time resulted in an increase in TiC particle size and volume fraction. Microhardness and shear punch tests demonstrated considerable improvement of the specimens’ mechanical properties with the increment of sintering time and GNS content up to 1 wt. %. The microhardness and shear strength of 1 wt. % GNS composites were enhanced from 316 HV and 610 MPa to 613 HV and 754 MPa, respectively, when composites sintered for 5 h. It is worth mentioning that the formation of the agglomerates of unreacted GNSs in 1.5 wt. % GNS composites resulted in a dramatic decrease in mechanical properties.

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Biomimetic composites inspired by venous leaf

Journal of Composite Materials ◽

10.1177/0021998317707254 ◽

2017 ◽

Vol 52 (3) ◽

pp. 361-372 ◽

Cited By ~ 2

Author(s):

Gongdai Liu ◽

R Ghosh ◽

A Vaziri ◽

A Hossieni ◽

D Mousanezhad ◽

...

Keyword(s):

Mechanical Properties ◽

Elastic Modulus ◽

Yield Stress ◽

Poisson’S Ratio ◽

Composite Structures ◽

Volume Fraction ◽

Matrix Material ◽

Poisson's Ratio ◽

Fiber Volume ◽

Young’S Moduli

A typical plant leaf can be idealized as a composite having three principal fibers: the central mid-fiber corresponding to the mid-rib, straight parallel secondary fibers attached to the mid-fiber representing the secondary veins, and then another set of parallel fibers emanating from the secondary fibers mimicking the tertiary fibers embedded in a matrix material. This paper introduces a biomimetic composite design inspired by the morphology of venous leafs and investigates the effects of venation morphologies on the in-plane mechanical properties of the biomimetic composites using finite element method. The mechanical properties such as Young’s moduli, Poisson’s ratio, and yield stress under uniaxial loading of the resultant composite structures was studied and the effect of different fiber architectures on these properties was investigated. To this end, two broad types of architectures were used both having similar central main fiber but differing in either having only secondary fibers or additional tertiary fibers. The fiber and matrix volume fractions were kept constant and a comparative parametric study was carried out by varying the inclination of the secondary fibers. The results show that the elastic modulus of composite in the direction of main fiber increases linearly with increasing the angle of the secondary fibers. Furthermore, the elastic modulus is enhanced if the secondary fibers are closed, which mimics composites with closed cellular fibers. In contrast, the elastic modulus of composites normal to the main fiber ( x direction) exponentially decreases with the increase of the angle of the secondary fibers and it is little affected by having secondary fibers closed. Similar results were obtained for the yield stress of the composites. The results also indicate that Poisson’s ratio linearly increases with the secondary fiber angle. The results also show that for a constant fiber volume fraction, addition of various tertiary fibers may not significantly enhance the mechanical properties of the composites. The mechanical properties of the composites are mainly dominated by the secondary fibers. Finally, a simple model was proposed to predict these behaviors.

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