Properties Improvement of Spark Plasma Sintered Ti-7Al-1Mo Ternary Alloy by TiN Nanoparticles Addition

2021 ◽  
Vol 55 ◽  
pp. 150-158
Author(s):  
Samson Olaitan Jeje ◽  
Mxolisi Brendon Shongwe ◽  
Azeez Lawan Rominiyi ◽  
Peter Apata Olubambi
Keyword(s):  
Electron Microscopy ◽  
Yield Strength ◽  
Ternary Alloy ◽  
Lamellar Structure ◽  
Compressive Yield Strength ◽  
Weight Percentage ◽  
Β Phase ◽  
Plasma Sintering ◽  
Tin Nanoparticles ◽  
Spark Plasma

Titanium (Ti) alloys are materials of interest in structural and chemical applications due to their low density, outstanding mechanical and chemical resistance properties. However, the mechanical properties still need to be enhanced to make them suitable as a replacement for Ni-based superalloys. There have been significant breakthroughs in the reinforcement of Ti alloy with a small weight percentage (wt.%) of ceramics. This work investigates the effect of TiN nanoparticles’ addition on the densification, phase transformation, microstructure, hardness, and compressive properties of Ti-7Al-1Mo ternary alloy. 3 wt.% of TiN nanoparticles was blended with Ti-7Al-1Mo powder, and the resulting admixed powder was consolidated via spark plasma sintering technique at 50 MPa pressure, 10 min holding time, and 1000 °C temperature. Scanning electron microscopy, transmission electron microscopy, and X-ray diffractometry were used to characterise the microstructure and phase composition respectively. The microstructure of Ti-7Al-1Mo revealed a lamellar structure with alpha (α) phase and minor beta (β) phase with visible grain boundaries, while TiN reinforced Ti-7Al-1Mo composite microstructure shows a bimodal structure with reduction in the lamellar structure. Ti-7Al-1Mo ternary alloy has a hardness value of 352±17 HV0.1 and a compressive yield strength of 985±31 MPa. The composite shows an increment of 74 HV and 323 MPa in its hardness and compressive yield strength respectively in comparison to the ternary alloy.

Mechanical properties of Mg-based materials fabricated by mechanical milling and spark plasma sintering

2018 ◽  
Vol 233 (10) ◽  
pp. 1972-1984 ◽  
Author(s):  
Mutlu Karasoglu ◽  
Serdar Karaoglu ◽  
Gursoy Arslan
Keyword(s):  
Grain Size ◽  
Yield Strength ◽  
Spark Plasma Sintering ◽  
Mechanical Milling ◽  
Microstructural Analysis ◽  
Compressive Yield Strength ◽  
X Ray ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Hardness Values

In this work, magnesium powders of different grain sizes were synthesized by mechanical milling for periods ranging from 0.5 to 30 h. Subsequent to milling, powders were consolidated by spark plasma sintering at 550 ℃ for 10 min. Before and after sintering, microstructural changes were investigated by analytical methods including X-ray diffraction (XRD), X-ray spectrometer, optical and electron microscopy. Analyses showed that nanocrystalline sizes were achieved by mechanical milling for milling times exceeding 5 h. Additionally, it was recognized that grain growth occurred during sintering, but to a limited extent. Mechanical test results displayed reasonable improvements in both compressive yield strength and hardness values with increasing milling times up to 5 h, where these reached their maximum values (245.5 MPa and 75.9 HV). The enhancement in these properties with increased milling time up to 5 h was attributed to both the extent of grain refinement and the formation of MgO together with incorporation of Fe particles, originating from the milling process, into the matrix. On the other hand, a substantial decrease in yield strength and hardness values in the samples milled in excess of 5 h were recorded, which in turn was related to the accompanying decline in bulk density of the samples. Microstructural analysis of the deformed samples revealed that grain size reduction suppressed twin formation, which elucidates the enhancement in ductility with decreasing grain size.

The effect of plastic deformation on mechanical properties of aluminium matrix composites reinforced with 2D crystals

2020 ◽  
Vol 111 (8) ◽  
pp. 632-638
Author(s):  
Jaroslaw Wozniak ◽  
Mateusz Petrus ◽  
Marek Kostecki ◽  
Tomasz Cygan ◽  
Andrzej Olszyna
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Yield Strength ◽  
Physical And Mechanical Properties ◽  
Compressive Yield Strength ◽  
Multilayer Graphene ◽  
Matrix Composites ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
2D Crystals

Abstract In this study, AA6061 matrix composites reinforced with multilayer graphene and MoS2 were analyzed. The composites were prepared by powder metallurgy using the spark plasma sintering and spark plasma texturing methods. Microstructure, physical and mechanical properties were investigated and compared with unreinforced AA6061 sinter and AA6061 sheet plate. The results showed that the application of spark plasma texturing positively influences the relative density and compressive yield strength of AA6061 matrix composites. Moreover, in composites with MoS2, significant differences in compressive yield strength between the centre and the edge of the sintered compacts were noticed. These differences are related to the formation of the MoAl12 phase as a result of the temperature gradient generated in the graphite die during sintering by the spark plasma texturing.

scholarly journals Microstructure and Mechanical Properties of Novel Lightweight TaNbVTi-Based Refractory High Entropy Alloys

Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 355
Author(s):  
Ao Fu ◽  
Yuankui Cao ◽  
Yuxi Liu ◽  
Shenghang Xu
Keyword(s):  
Yield Strength ◽  
Volume Fraction ◽  
High Volume ◽  
Specific Yield ◽  
Compressive Yield Strength ◽  
High Entropy Alloys ◽  
High Entropy ◽  
Solid Solution Strengthening ◽  
Plasma Sintering ◽  
Spark Plasma

A series of novel lightweight TaNbVTi-based refractory high entropy alloys (RHEA) were fabricated through ball-milling and spark plasma sintering (SPS). The reinforced phase of TiO precipitates were in-situ formed due to the introduction of Al2O3 ceramic particles. The RHEA with 15% Al2O3 exhibits a high compressive yield strength (1837 MPa) and a low density (7.75 g/cm3) with an adequate ductility retention. The yield strength and density are 32% higher and 15% lower, respectively, compared to the RHEA without Al2O3 addition. The specific yield strength (237 MPa cm3/g) of the RHEAs is much higher than that of other reported RHEAs, and is mainly ascribed to the introduction of high volume fraction of Al2O3 additives, resulting in solid solution strengthening and precipitation strengthening. Meanwhile, the ductile matrix is responsible for the good compressive plasticity.

scholarly journals Compressive strength and thermal properties of spark plasma sintered Al-Al2O3 nanocomposite

2018 ◽  
Vol 50 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Nouari Saheb ◽  
Muhammad Khan
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Thermal Properties ◽  
Yield Strength ◽  
Coefficient Of Thermal Expansion ◽  
Testing Machine ◽  
Thermal Constant ◽  
Compressive Properties ◽  
Plasma Sintering ◽  
Spark Plasma

In this work, compressive and thermal properties of aluminum, milled aluminum, and Al-10Al2O3 composite processed via ball milling (BM) and spark plasma sintering (SPS) were investigated. The microstructural features of powders and sintered samples were characterized using optical and scanning electron microscopy. A universal testing machine was used to determine the compressive properties of the consolidated samples. The thermal conductivity and coefficient of thermal expansion of the developed materials were characterized using a hot disc thermal constant analyzer and a dilatometer, respectively. The Al-10Al2O3 composite possessed hardness of 1309.7 MPa, yield strength of 311.4 MPa, and compressive strength of 432.87 MPa compared to hardness of 326.3 MPa, yield strength of 74.33 MPa, and compressive strength of 204.43 MPa for aluminum. The Al-10Al2O3 composite had thermal conductivity value 81.42 W/mK compared to value of 198.09 W/mK for aluminum. In the temperature range from 373 K to 723 K, the composite had lower CTEs ranging from 10 ? 10?6 to 22 ? 10?6/K compared to 20 ? 10?6 to 30 ? 10?6/K for aluminum.

scholarly journals Microstructure Evolution of Mg96.9Gd2.7Zn0.4 Alloy Containing Multiple Phases Prepared by Spark Plasma Sintering Method

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1355
Author(s):  
Zhiyong Xue ◽  
Xiuzhu Han ◽  
Wenbo Luo ◽  
Zhiyong Zhou ◽  
Zhizhong Cheng ◽  
...  
Keyword(s):  
Spark Plasma Sintering ◽  
Rapid Solidification ◽  
High Performance ◽  
Aging Treatment ◽  
Lpso Phase ◽  
Β Phase ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Molten Liquid ◽  
Sintering Method

The synergic strengthening of multiple phases is an essential way to achieve high-performance Mg alloys. Herein, Mg-Gd-Zn alloy containing four phases was prepared by rapid solidification (RS) ribbons and spark plasma sintering (SPS). The microstructure of the alloy consisted of α-Mg, nanosized β1 phase particles, lamellar long period stacking ordered (LPSO) phase, and β′ phase precipitates. The microstructural evolution was also investigated. The results show that the metastable β1 phase was formed in the as-cast solidification through rapid solidification, because both Zn atoms and the short holding-time at molten liquid facilitated the formation of the β1 phase. The β1 phase grew from 35.6 to 154 nm during the sintering process. Meanwhile, the fine lamellar LPSO phase was simultaneously formed after the Zn-Gd clusters were generated from the supersaturated solid solution, and the width of the LPSO phase was only in the range of 2–30 nm. The third strengthening phase, the metastable β′ phase, was obtained by aging treatment. The results of hardness testing implied that the hardness of the alloy containing the aforementioned three nanosized strengthening phases significantly improved about 47% to 126 HV compared with that of the as-cast ingot.

Spark Plasma Sintering and Strength Behavior under Compressive Loading of Mg-PSZ/Al2O3-TRIP-Steel Composites

2015 ◽  
Vol 825-826 ◽  
pp. 182-188 ◽  
Author(s):  
Lutz Krüger ◽  
Steffen Grützner ◽  
Sabine Decker ◽  
Ines Schneider
Keyword(s):  
Strain Rate ◽  
Spark Plasma Sintering ◽  
Trip Steel ◽  
Volume Fraction ◽  
Compressive Yield Strength ◽  
Strain Rates ◽  
Steel Matrix ◽  
Trip Effect ◽  
Plasma Sintering ◽  
Spark Plasma

Composite materials, which consist of a metastable austenitic TRIP-steel matrix (CrMnNi TRIPsteel; TRansformation Induced Plasticity) reinforced by alumina particles (25 vol.% ceramic, designated as AT 25/75) and reinforced by alumina and MgO partially stabilized zirconia particles (Mg-PSZ) (35 vol.% ceramic, designated as AT 25/75 + MgPSZ) were synthesized through spark plasma sintering (SPS). In the AT 25/75 + MgPSZ, the steel particles were mainly surrounded by alumina. Hence, mostly steel/alumina and alumina/MgPSZ interfaces existed. The mechanical behavior of the as-sintered samples was characterized by compression tests at room temperature and 40 °C and in a range of strain rates between 103s-1and 103s1. The influence of the ceramic content, strain rate and temperature on TRIP-effect of the steel matrix was investigated. Due to the increasing ceramic volume fraction, AT 25/75 + MgPSZ exhibits the highest compressive yield strength under all loading conditions and no strain rate sensitivity. This composite showed no measurable TRIP-effect, due to the low fracture strain. The deformation-induced α’martensite within the steel particles in pure steel and AT 25/75 primary depends on the testing temperature and the strain rate. This is attributed to an increase of stacking fault energy with rising temperature. High strain rates cause adiabatic heating, counteracting the martensitic transformation.

Effect of the Dwell Temperature on Spark Plasma Sintered CaCu3Ti4O12

2012 ◽  
Vol 727-728 ◽  
pp. 982-987
Author(s):  
E. de Carvalho ◽  
Marcelo Bertolete ◽  
Izabel Fernanda Machado ◽  
E.N.S. Muccillo
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Lattice Parameter ◽  
Solid State Reactions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Diffraction Patterns ◽  
Scanning Electron

Polycrystalline CaCu3Ti4O12 ceramics were prepared by solid state reactions by spark plasma sintering (SPS) technique. In this study, the effects of the dwell temperature on structural, microstructural and dielectric properties of CaCu3Ti4O12 ceramics have been investigated. Powder mixtures were calcined at 900°C for 18 h before SPS consolidation. The dwell temperatures were 850, 900, 915 and 930°C. Sintered pellets were characterized by X-ray diffraction, scanning electron microscopy and impedance spectroscopy. X-ray diffraction patterns show evidences of a single-phase perovskite-type structure. The calculated lattice parameter is 7.40 Å. The hydrostatic density increases slightly with increasing dwell temperature. Scanning electron microscopy observations revealed a heterogeneous microstructure for all samples. The dielectric loss remains constant over a wide temperature range. The obtained permittivity is approximately 103 at 1 kHz. The increase of the dwell temperature is found to produce a brittle ceramic.

THE GROWTH OF MnSi1.73 PREPARED BY SPARK PLASMA SINTERING

2004 ◽  
Vol 18 (01) ◽  
pp. 87-93 ◽  
Author(s):  
ZHIMIN WANG ◽  
YIDONG WU ◽  
YUANJIN HE
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Spark Plasma Sintering ◽  
X Ray Diffraction ◽  
Mechanical Pressure ◽  
Growth Processes ◽  
X Ray ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Scanning Electron

Crystals of MnSi 1.73 were prepared by Spark Plasma Sintering (SPS) technique, analyzed by X-ray diffraction (XRD), and invested by metalogragh and scanning electron microscopy (SEM). The growth processes of the samples were studied. It was found that the Mn–Si powders partly formed MnSi 1.73 crystals at 912–937 K under the mechanical pressure of 20 MPa in low vacuum (about 5.0 Pa), and fully formed MnSi 1.73 crystals after sintered at 1173 K for 15 minutes under 40 MPa.

Evaluation of an original use of spark plasma sintering to laminate carbon fibres reinforced aluminium

2017 ◽  
Vol 52 (16) ◽  
pp. 2149-2161 ◽  
Author(s):  
Christophe Perron ◽  
Corinne Arvieu ◽  
Eric Lacoste
Keyword(s):  
Electron Microscopy ◽  
Spark Plasma Sintering ◽  
Raw Material ◽  
Foil Thickness ◽  
Reactive System ◽  
Carbide Formation ◽  
Carbon Fibres ◽  
Liquid Aluminium ◽  
Plasma Sintering ◽  
Spark Plasma

An alternative route for producing aluminium matrix reinforced with continuous carbon fibres is proposed in this paper. On the one hand, liquid aluminium does not wet carbon; on the other hand, however, the two form a reactive system leading to carbide formation. A novel way to obtain continuous carbon fibre-reinforced aluminium was investigated, using spark plasma sintering with aluminium foils as raw material. Sintering parameters were adjusted to achieve the effective welding of aluminium foils and penetration of the metal between the filaments. A quality assessment of the fibre/aluminium coupling is presented. Interfaces were then investigated by scanning electron microscopy, transmission electron microscopy and energy-dispersive ray spectroscopy. An effective cohesion of fibres with the matrix was shown. The manageable fibre positioning could result in unidirectional architecture and reinforcement rate should be handled through foil thickness and yarn properties. Using tensile tests, cohesion between aluminium and carbon fibres can be quantified.

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