The Fabrication and Characterization of Spark Plasma Sintered Nickel Based Binary Alloy at Different Heating Rate

2019 ◽  
Vol 7 (3) ◽  
Author(s):  
B. J. Babalola ◽  
M. B. Shongwe ◽  
A. L. Rominiyi ◽  
P. L. Lepele ◽  
A. P. I. Popoola
Keyword(s):  
Relative Density ◽  
Heating Rate ◽  
Binary Alloy ◽  
Microstructural Analysis ◽  
Deformation Mode ◽  
Xrd Analysis ◽  
Ductile Deformation ◽  
Indentation Hardness ◽  
Sintered Alloy ◽  
Spark Plasma

In this paper, the effect of heating rate was investigated on the densification and mechanical properties of Ni–19at %Cr binary alloy developed by spark plasma sintering technique. The sintered binary alloy at different heating rate was prepared metallurgically for microstructural analysis, nanoindentation, and X-ray diffraction (XRD) analysis. Nanoindentation technique at room temperature was utilized in investigating the elastic modulus, and hardness of the alloys. However, nanoindentation tests showed that the maximum indentation hardness was obtained by the alloy sintered at heating rate of 100 °C/min, the hardness value and density were observed to decreases as the heating rate increases beyond 100 °C/min. Similar trend was observed for the relative density of the alloys, with the relative density decreasing as heating rate increases beyond 100 °C/min. The fractography analysis of the sintered alloy at different heating rate was characterized by ductile deformation mode.

Fabrication of High Dense ZnSe Ceramic by Spark Plasma Sintering: The Effect of the Powder Process Method

2018 ◽  
Vol 281 ◽  
pp. 661-666
Author(s):  
Jia Lin Gao ◽  
Peng Liu ◽  
Jian Zhang ◽  
Xiao Dong Xu ◽  
Ding Yuan Tang
Keyword(s):  
Relative Density ◽  
Ball Milling ◽  
Heating Rate ◽  
Spark Plasma Sintering ◽  
Zinc Selenide ◽  
Plasma Sintering ◽  
Planetary Ball Milling ◽  
Spark Plasma ◽  
Process Method

Zinc Selenide ceramic was successfully fabricated by spark plasma sintering in the study. The ZnSe raw powders were handled with two different methods such as grinding and planetary ball milling, respectively. The relative density, microstructure and transmittance of the ZnSe ceramic sintered under the same sintering parameter with two type powders was investigated. The results shown that the performance of the powder processed by ball milling was more effective than that by grinding. Furthermore, the maximum relative density can reach 99.8% when the ZnSe powder treated by ball milling were sintered at 950 oC for 30 min with the heating rate of 10 oC/min under 100 MPa.

scholarly journals The Effect of SiC Content on Microstructure and Microwave Heating Rate of h-BN/SiC Ceramics Fabricated by Spark Plasma Sintering

Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 1909 ◽  
Author(s):  
Huilin Lun ◽  
Yi Zeng ◽  
Xiang Xiong ◽  
Lei Zhao ◽  
Dongling Li ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Relative Density ◽  
Heating Rate ◽  
Spark Plasma Sintering ◽  
Hexagonal Boron Nitride ◽  
Molar Ratio ◽  
Molar Ratios ◽  
Sic Ceramics ◽  
Plasma Sintering ◽  
Spark Plasma

Hexagonal boron nitride/silicon carbide (h-BN/SiC) ceramics were fabricated by a spark plasma sintering (SPS) method. Phase and microstructure of ceramics were characterized and observed, respectively, using the X-ray diffraction, scanning electron microscope and electron probe microanalysis. The effect of molar ratios of SiC to h-BN on the microstructure, relative density, hardness, thermal conductivity, and the heating rate by microwaves on the ceramics were investigated. The results showed that the orientation of flake-like h-BN was significantly influenced by SiC content in h-BN/SiC ceramics. With the increasing of SiC content, the h-BN flakes gradually became an isotropic distribution from the preferred orientation aligning in a SPS pressure direction. The relative density of h-BN/SiC ceramics was 97.6 ± 0.9% at a molar ratio of SiC to h-BN of 40/60 mol%. The preferential orientation of h-BN flakes contributed to a relatively high thermal conductivity along the SPS pressure direction, which was beneficial to increasing the heating rate of h-BN/SiC ceramics in microwave fields.

Synthesis, Microstructure and Mechanical Properties of ZrB2 Ceramic Prepared by Mechanical Alloying and Spark Plasma Sintering

2010 ◽  
Vol 434-435 ◽  
pp. 165-168 ◽  
Author(s):  
Chun Feng Hu ◽  
Yoshio Sakka ◽  
Tetsuo Uchikoshi ◽  
Tohru Suzuki ◽  
Byung Koog Jang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Mechanical Alloying ◽  
Relative Density ◽  
Heating Rate ◽  
Spark Plasma Sintering ◽  
Vickers Hardness ◽  
Heating Rates ◽  
Plasma Sintering ◽  
Spark Plasma

Dense bulk ZrB2 ceramic was synthesized by mechanical alloying (MA) and followed spark plasma sintering (SPS) using zirconium and boron as initial materials. It was found that MA process was effective to fragment the coarse metal zirconium particles from 45 m to less than 1 m within 20 hours. In comparison with the commercial ZrB2 powder, the as-obtained zirconium and boron mixture powders showed higher sinterability. When the sintering was carried out at 1800oC, the relative density of synthesized ZrB2 samples using mixture powder was above 95%, higher than that of ZrB2 sample prepared using commercial powder (73%). Vickers hardness of those ZrB2 samples was at the same level of 15 GPa. However, the fracture toughness of ZrB2 samples seemed to depend on the heating rate of the SPS process. Corresponding to the heating rates of 10, 50, and 100oC/min, the fracture toughness of as-prepared ZrB2 samples were 3.83, 3.19, and 2.74 MPa•m1/2, respectively.

scholarly journals The effects of particle size distribution and sintering conditions on bending strength of sintered Ni-30%Fe alloys

2018 ◽  
Vol 7 (3) ◽  
pp. 1581
Author(s):  
Mxolisi B. Shongwe ◽  
Olawale O. Ajibola ◽  
Munyadziwa M. Ramakokovhu ◽  
Peter A. Olubambi
Keyword(s):  
Heating Rate ◽  
Bending Strength ◽  
High Heating Rate ◽  
Sintered Alloy ◽  
Metal Powders ◽  
X Ray ◽  
Plasma Sintering ◽  
Grain Size Distributions ◽  
Spark Plasma ◽  
Fe Alloys

This work reports effect of the powder grain size distributions on the bending strength sintered Ni-30%Fe alloys obtained from mixed coarse-fine micron size metal powders. Two dissimilar particle sizes of Ni and Fe metal powders were mixed by subjecting them to translational and rotational agitations using the T2F Turbula Shaker Mixer. The mixed powders were moulded using graphite dies and sintered in vacuum and at constant pressure using Spark Plasma Sintering furnace (HHPD-25). The ratios of the two metals were varied as well as the sintering temperature and time. The morphology and microstructures of both powders and sinters were studied using field emission scanning electron microscopy (JSM-7600F) equipped with energy dispersive X-ray spectrometer (EDS) facilities. The phases in the sintered specimens were characterized by X-ray diffraction (XRD). The densities of the samples were determined, The Vickers microhardness at room temperature and bending strength of the sintered alloy specimens were measured. Comparatively, low heating rate (50 oC/min) produced enhanced microstructures hence higher bonding, bending strength and densification than samples at high heating rate (150 oC/min).  

Microstructure and Mechanical Properties of TiB-Ti/Ti-6Al-4V Composites Fabricated by Spark Plasma Sintering

2015 ◽  
Vol 782 ◽  
pp. 107-112
Author(s):  
Li Fen Wang ◽  
Zhao Hui Zhang ◽  
Tie Jian Su ◽  
Fu Chi Wang
Keyword(s):  
Mechanical Properties ◽  
Relative Density ◽  
Heating Rate ◽  
Spark Plasma Sintering ◽  
Fracture Strength ◽  
Sintering Temperature ◽  
Composite Layer ◽  
Micro Hardness ◽  
Plasma Sintering ◽  
Spark Plasma

TiB-Ti/Ti-6Al-4V composites were fabricated by spark plasma sintering (SPS) technique under a pressure of 50MPa, with sintering temperature of 1300 °C and heating rate of 100 °C /min. The effect of the TiB content in TiB-Ti composite layer on microstructures and mechanical properties of the TiB-Ti/Ti-6Al-4V composites were investigated. The results indicate that as an advanced welding method, SPS technique provided the excellent welding combination of TiB-Ti and Ti-6Al-4V. The relatively excellent mechanical properties of the joints, including the relative density of 98.6%, micro-hardness of 10.2GPa, fracture strength of 177MPa were achieved as TiB content in TiB-Ti composite layer reaches 50%.

scholarly journals Fluid-mediated, brittle-ductile deformation at seismogenic depth: Part II – Stress history and fluid pressure variations in a shear zone in a nuclear waste repository (Olkiluoto Island, Finland)

2019 ◽  
Author(s):  
Francesca Prando ◽  
Luca Menegon ◽  
Mark W. Anderson ◽  
Barbara Marchesini ◽  
Jussi Mattila ◽  
...  
Keyword(s):  
Nuclear Waste ◽  
Electron Backscatter Diffraction ◽  
Microstructural Analysis ◽  
Fluid Pressure ◽  
Deformation Mode ◽  
Mineral Chemistry ◽  
Ductile Deformation ◽  
Rheological Parameters ◽  
Nuclear Waste Repository ◽  
Brittle Ductile Transition

Abstract. Microstructural record of fault rocks active at the brittle ductile transition zone (BDTZ) may retain information on the rheological parameters driving the switch in deformation mode, and on the role of stress and fluid pressure in controlling different fault slip behaviours. In this study we analysed the deformation microstructures of the strike-slip fault zone BFZ045 in Olkiluoto (SW Finland), located in the site of a deep geological repository for nuclear waste. We combined microstructural analysis, electron backscatter diffraction (EBSD), and mineral chemistry data to reconstruct the variations in pressure, temperature, fluid pressure and differential stress that mediated deformation and strain localization along BFZ045 across the BDTZ. BFZ045 exhibits a mixed ductile-brittle deformation, with a narrow (

Spark Plasma Sintering of Hybrid Nanocomposites of Hydroxyapatite Reinforced with CNTs and SS316L for Biomedical Applications

2020 ◽  
Vol 16 (4) ◽  
pp. 578-583
Author(s):  
Muhammad Asif Hussain ◽  
Adnan Maqbool ◽  
Abbas Saeed Hakeem ◽  
Fazal Ahmad Khalid ◽  
Muhammad Asif Rafiq ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Spark Plasma Sintering ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Hybrid Nanocomposites ◽  
Homogeneous Distribution ◽  
Sintering Behavior ◽  
Stainless Steel 316L ◽  
Plasma Sintering ◽  
Spark Plasma

Background: The development of new bioimplants with enhanced mechanical and biomedical properties have great impetus for researchers in the field of biomaterials. Metallic materials such as stainless steel 316L (SS316L), applied for bioimplants are compatible to the human osteoblast cells and bear good toughness. However, they suffer by corrosion and their elastic moduli are very high than the application where they need to be used. On the other hand, ceramics such as hydroxyapatite (HAP), is biocompatible as well as bioactive material and helps in bone grafting during the course of bone recovery, it has the inherent brittle nature and low fracture toughness. Therefore, to overcome these issues, a hybrid combination of HAP, SS316L and carbon nanotubes (CNTs) has been synthesized and characterized in the present investigation. Methods: CNTs were acid treated to functionalize their surface and cleaned prior their addition to the composites. The mixing of nano-hydroxyapatite (HAPn), SS316L and CNTs was carried out by nitrogen gas purging followed by the ball milling to insure the homogeneous mixing of the powders. In three compositions, monolithic HAPn, nanocomposites of CNTs reinforced HAPn, and hybrid nanocomposites of CNTs and SS316L reinforced HAPn has been fabricated by spark plasma sintering (SPS) technique. Results: SEM analysis of SPS samples showed enhanced sintering of HAP-CNT nanocomposites, which also showed significant sintering behavior when combined with SS316L. Good densification was achieved in the nanocomposites. No phase change was observed for HAP at relatively higher sintering temperatures (1100°C) of SPS and tricalcium phosphate phase was not detected by XRD analysis. This represents the characteristic advantage with enhanced sintering behavior by SPS technique. Fracture toughness was found to increase with the addition of CNTs and SS316L in HAPn, while hardness initially enhanced with the addition of nonreinforcement (CNTs) in HAPn and then decrease for HAPn-CNT-SS316L hybrid nanocomposites due to presence of SS316L. Conclusion: A homogeneous distribution of CNTs and SPS technique resulted in the improved mechanical properties for HAPn-CNT-SS316L hybrid nanocomposites than other composites and suggested their application as bioimplant materials.

scholarly journals Comparison of Conventional and Flash Spark Plasma Sintering of Cu–Cr Pseudo-Alloys: Kinetics, Structure, Properties

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 141
Author(s):  
Kirill V. Kuskov ◽  
Mohammad Abedi ◽  
Dmitry O. Moskovskikh ◽  
Illia Serhiienko ◽  
Alexander S. Mukasyan
Keyword(s):  
Heating Rate ◽  
Spark Plasma Sintering ◽  
Electric Circuits ◽  
Nanostructured Particles ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
The Media ◽  
Copper Chromium ◽  
Kinetics Of ◽  
Structure Properties

Spark plasma sintering (SPS) is widely used for the consolidation of different materials. Copper-based pseudo alloys have found a variety of applications including as electrodes in vacuum interrupters of high-voltage electric circuits. How does the kinetics of SPS consolidation for such alloys depend on the heating rate? Do SPS kinetics depend on the microstructure of the media to be sintered? These questions were addressed by the investigation of SPS kinetics in the heating rate range of 0.1 to 50 K/s. The latter conditions were achieved through flash spark plasma sintering (FSPS). We also compared the sintering kinetics for the conventional copper–chromium mixture and for the mechanically induced copper/chromium nanostructured particles. It was shown that, under FSPS conditions, the observed maximum consolidation rates were 20–30 times higher than that for conventional SPS with a heating rate of 100 K/min. Under the investigated conditions, the sintering rate for mechanically induced composite Cu/Cr particles was 2–4 times higher compared to the conventional Cu + Cr mixtures. The apparent sintering activation energy for the Cu/Cr powder was twice less than that for Cu–Cr mixture. It was concluded that the FSPS of nanostructured powders is an efficient approach for the fabrication of pseudo-alloys.

scholarly journals Microstructure evolution of TC4 powder by spark plasma sintering after hot deformation

2020 ◽  
Vol 39 (1) ◽  
pp. 457-465
Author(s):  
Jiangpeng Yan ◽  
Zhimin Zhang ◽  
Jian Xu ◽  
Yaojin Wu ◽  
Xi Zhao ◽  
...  
Keyword(s):  
Strain Rate ◽  
Relative Density ◽  
Spark Plasma Sintering ◽  
Hot Deformation ◽  
Tc4 Titanium Alloy ◽  
Weave Structure ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Average Relative Density ◽  
Low Strain Rate

AbstractThe cylindrical samples of TC4 titanium alloy prepared by spark plasma sintering (SPS) were compressed with hot deformation of 70% on the thermosimulation machine of Gleeble-1500. The temperature of the processes ranged from 850°C to 1,050°C, and the strain rates varied between 0.001 and 5 s−1. The relative density of the sintered and compressed samples was measured by the Archimedes principle. During hot deformation, the microstructure of the sample was observed. The results show that the average relative density of the samples was 90.2% after SPS. And the relative density was about 98% after the hot deformation of 70%. Under high temperature (>950°C), the sensitivity of flow stress to temperature was reduced. At low strain rate (0.001 s−1), the increase in the deformation temperature promoted the growth of dynamic recrystallization (DRX). At the same temperature, the increase in strain rate slowed down the growth of DRX grains. And the variation tendency was shown from the basket-weave structure to the Widmanstätten structure at a low strain rate (<0.1 s−1), with increase in the strain rate.

scholarly journals Effect of Molybdenum Content on the Corrosion and Microstructure of Low-Ni, Co-Free Maraging Steels

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 852
Author(s):  
Asiful H. Seikh ◽  
Hossam Halfa ◽  
Mahmoud S. Soliman
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance ◽  
Microstructural Analysis ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Alloying Element ◽  
X Ray ◽  
Maraging Steels ◽  
Eds Analysis ◽  
Electroslag Refining

Molybdenum (Mo) is an important alloying element in maraging steels. In this study, we altered the Mo concentration during the production of four cobalt-free maraging steels using an electroslag refining process. The microstructure of the four forged maraging steels was evaluated to examine phase contents by optical microscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD) analysis. Additionally, we assessed the corrosion resistance of the newly developed alloys in 3.5% NaCl solution and 1 M H2SO4 solution through potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. Furthermore, we performed SEM and energy-dispersive spectroscopy (EDS) analysis after corrosion to assess changes in microstructure and Raman spectroscopy to identify the presence of phases on the electrode surface. The microstructural analysis shows that the formation of retained austenite increases with increasing Mo concentrations. It is found from corrosion study that increasing Mo concentration up to 4.6% increased the corrosion resistance of the steel. However, further increase in Mo concentration reduces the corrosion resistance.

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