scholarly journals Ceramics based on concrete wastes prepared by spark plasma sintering

2021 ◽  
Vol 15 (1) ◽  
pp. 100-109
Author(s):  
Mohammed Abass ◽  
Yasuyuki Kanda
Keyword(s):  
Flexural Strength ◽  
Spark Plasma Sintering ◽  
Liquid Phase Sintering ◽  
Recycled Concrete ◽  
Raw Material ◽  
Recycled Aggregate ◽  
Fine Aggregate ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Sand Particles

An effective utilization technique is required to recycle fine aggregate in concrete waste because the presence of residual waste cement reduces the quality of the recycled concrete. In this study, recycled aggregate powder (RAP) was prepared by milling Okinawan concrete waste and developing a ceramic compact with high flexural strength using the spark plasma sintering (SPS) method. The RAP raw material consisted mainly of calcite and quartz. The densification gradient of the sintered compact was uniform during sintering at 1123-1273K. At 1273K sintering temperature, Vickers hardness (HV) obtained a maximum of 393 along with 78.9MPa maximum flexural strength, which exceeded the porcelain stoneware tile ISO 13006 standards. Scanning electron microscopy with energy dispersive X-ray (SEM-EDX) element analysis suggested that the inner structure constituted unmelted silica-rich sand particles and melted calcium-rich particles containing waste cement and fine aggregate with limestone. Therefore, it can be concluded that SPS progressed by the liquid-phase sintering phenomenon between sand particles and calcium-rich particles, which contributed to flexural strength and modulus improvement.

scholarly journals Synthesis, microstructure, and properties of high purity Mo2TiAlC2 ceramics fabricated by spark plasma sintering

2020 ◽  
Vol 9 (6) ◽  
pp. 759-768
Author(s):  
Yunhui Niu ◽  
Shuai Fu ◽  
Kuibao Zhang ◽  
Bo Dai ◽  
Haibin Zhang ◽  
...  
Keyword(s):  
Grain Size ◽  
Flexural Strength ◽  
Spark Plasma Sintering ◽  
Layered Structure ◽  
High Purity ◽  
High Fracture Toughness ◽  
Temperature Range ◽  
Microstructure And Properties ◽  
Plasma Sintering ◽  
Spark Plasma

AbstractThe synthesis, microstructure, and properties of high purity dense bulk Mo2TiAlC2 ceramics were studied. High purity Mo2TiAlC2 powder was synthesized at 1873 K starting from Mo, Ti, Al, and graphite powders with a molar ratio of 2:1:1.25:2. The synthesis mechanism of Mo2TiAlC2 was explored by analyzing the compositions of samples sintered at different temperatures. It was found that the Mo2TiAlC2 phase was formed from the reaction among Mo3Al2C, Mo2C, TiC, and C. Dense Mo2TiAlC2 bulk sample was prepared by spark plasma sintering (SPS) at 1673 K under a pressure of 40 MPa. The relative density of the dense sample was 98.3%. The mean grain size was 3.5 μm in length and 1.5 μm in width. The typical layered structure could be clearly observed. The electrical conductivity of Mo2TiAlC2 ceramic measured at the temperature range of 2–300 K decreased from 0.95 × 106 to 0.77 × 106 Ω–1·m–1. Thermal conductivity measured at the temperature range of 300–1273 K decreased from 8.0 to 6.4 W·(m·K)–1. The thermal expansion coefficient (TEC) of Mo2TiAlC2 measured at the temperature of 350–1100 K was calculated as 9.0 × 10–6 K–1. Additionally, the layered structure and fine grain size benefited for excellent mechanical properties of low intrinsic Vickers hardness of 5.2 GPa, high flexural strength of 407.9 MPa, high fracture toughness of 6.5 MPa·m1/2, and high compressive strength of 1079 MPa. Even at the indentation load of 300 N, the residual flexural strength could hold 84% of the value of undamaged one, indicating remarkable damage tolerance. Furthermore, it was confirmed that Mo2TiAlC2 ceramic had a good oxidation resistance below 1200 K in the air.

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.

scholarly journals Effect of Doped CeO with Si3N4 Powders on the Densification Mechanism During

2021 ◽  
Author(s):  
Yao Liu
Keyword(s):  
Liquid Phase ◽  
Relative Density ◽  
Stress Exponent ◽  
Spark Plasma Sintering ◽  
Liquid Phase Sintering ◽  
Creep Model ◽  
Stress Regime ◽  
Densification Mechanism ◽  
Plasma Sintering ◽  
Spark Plasma

Abstract The densification mechanism of doped CeO with Si3N4 powder during Spark Plasma Sintering (SPS) was investigated under temperatures ranging from 1500 to 1750 °C at soaking pressures of 30, 40, 50 MPa. Results showed that the relative density of Si3N4 ceramics sintered at 1650 °C and 30 MPa was 97.9%. A creep model was employed to determine the mechanism, which can be interpreted on the basis of the stress exponent (n). The results showed that the mechanism was controlled by liquid phase sintering at low effective stress regime (n=1).

scholarly journals The Analysis of Erosive Wear Resistance of WC-Co Carbides Obtained by Spark Plasma Sintering Method

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7326
Author(s):  
Joanna Wachowicz ◽  
Tomasz Dembiczak ◽  
Grzegorz Stradomski ◽  
Zbigniew Bałaga ◽  
Joanna Jasińska ◽  
...  
Keyword(s):  
Spark Plasma Sintering ◽  
Quartz Sand ◽  
Metal Cutting ◽  
Oriented Strand Board ◽  
Cutting Tools ◽  
Erosive Wear ◽  
Plasma Sintering ◽  
Erosion Models ◽  
Spark Plasma ◽  
Sand Particles

WC-Co (tungsten carbide-cobalt) composites are widely used in industry, wear-resistant parts, and cutting tools. As successful tool materials, WC-Co carbides are widely applied in metal cutting, wear applications, chipless forming, stoneworking, wood, and plastic working. These materials are exposed to severe solid particle erosion by sand particles, such as in the wood industry. During the production of furniture with HDF (High Density Fibreboard), MDF (Medium Density Fibreboard), or OSB (Oriented Strand Board), there are observed problems with tool erosion. Contamination, mainly of the HDF by sand, is quite often, which is why all tools used for the machining of such materials are exposed to erosion by sand particles. Although many studies have been performed on the erosion of various metals, and erosion models exist to predict their erosion behavior, the issue is still relevant. The aim of the study was to determine the effect of grain size (submicron, ultrafine) and the manufacturing technology (SPS—Spark Plasma Sintering, conventional) used on the erosive properties of WC-Co sintered carbides. Sinters produced by the SPS method with different sizes of WC grains and commercial samples were used for the tests. Ten two-hour cycles were carried out under medium conditions of quartz sand and quartz sand with 10% SiC added. Used samples were characterised using scanning electron microscopy (SEM) and roughness was determined. Furthermore, erosion studies allowed individuating a wear mechanism as well as the possibility to foresee cutting performance in prospective application.

Liquid Phase Sintering of α-Si3N4 by Spark Plasma Sintering

2007 ◽  
Vol 336-338 ◽  
pp. 1062-1064 ◽  
Author(s):  
Fa Qiang Yan ◽  
Fei Chen ◽  
Qiang Shen ◽  
Lian Meng Zhang
Keyword(s):  
Liquid Phase ◽  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Liquid Phase Sintering ◽  
Sintering Behavior ◽  
Sintering Aids ◽  
Factors Influencing ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Si3n4 Ceramics

In this study, spark plasma sintering (SPS) was applied to prepare α-Si3N4 ceramics of different densities with magnesia, silicon dioxide, alumina as the sintering aids. The sintering behavior and liquid phase sintering (LPS) mechanism were discussed and the factors influencing the density of the prepared samples were analyzed. Microstructures of sintered samples were observed and the phase compositions were analyzed. The results showed that α-Si3N4 ceramics can be sintered by SPS based on the reaction among α-Si3N4 and sintering additives which lead to the liquid phase and the density can be well controlled from 2.48 to 3.09 g/cm3 while the content of the sintering aids changes from 10% to 28.5% and sintering temperature from 1400°C to 1500°C.

Microstructural Development of SiC Ceramics by Liquid-Phase Sintering with Spark Plasma Sintering Technique

2006 ◽  
Vol 510-511 ◽  
pp. 1022-1025 ◽  
Author(s):  
Mikinori Hotta ◽  
Junichi Hojo
Keyword(s):  
Grain Size ◽  
Spark Plasma Sintering ◽  
Liquid Phase Sintering ◽  
Molar Ratio ◽  
Microstructural Development ◽  
Sic Ceramics ◽  
Plasma Sintering ◽  
N2 Atmosphere ◽  
Average Grain Size ◽  
Spark Plasma

Sub-micron and nano-sized β-SiC powders were sintered with AlN and Y2O3 as sintering additives by spark plasma sintering (SPS). The sintered densities reached >95% of theoretical with a different molar ratio of AlN to Y2O3 at total amount of 10vol% and temperature of 1900oC for 10min in N2 atmosphere under a pressure of 30MPa. With increasing amount of the AlN additive, the size of SiC grains decreased and the shape changed from globular to columnar. The fully densified SiC at AlN:Y2O3=95:5mol% had an average grain size of 0.5-1µm and 50-100nm in diameter by using sub-micron and nano-sized SiC starting powders, respectively. Flexural strength of the specimen having grain size of 0.5-1µm was approximately 1200MPa at room temperature.

Spark Plasma Sintering of SiC Ceramics Based on Natural Renewable Raw Materials

2020 ◽  
Vol 992 ◽  
pp. 759-763
Author(s):  
A. Zavjalov ◽  
Nikolai P. Shapkin ◽  
Evgenii K. Papynov
Keyword(s):  
Spark Plasma Sintering ◽  
Raw Materials ◽  
Inert Atmosphere ◽  
Raw Material ◽  
Strength Analysis ◽  
Organic Part ◽  
Sic Ceramics ◽  
Plasma Sintering ◽  
Sic Ceramic ◽  
Spark Plasma

The paper presents the results of obtaining silicon carbide SiC ceramic from organic raw materials by the reaction spark plasma sintering (SPS). Annealed rice husks are used as an organic raw material. A feature of the batch preparation for sintering is annealing in an inert atmosphere. Thus, the carbon source C for further reaction with silicon dioxide SiO2 to form SiC is the organic part of the rice husk. This way let to achieve the most uniform reacting components mixing directly at the stage of annealing the husks and to exclude the mixing stage from the technological process. The reaction SPS method was used for the first time for the production of ceramic material from such a raw material. The results of a comprehensive study of the obtained material by various methods are presented in the article: scanning electron microscopy, Raman spectroscopy, X-ray phase analysis, strength analysis, and others.

Sign in / Sign up

Export Citation Format

Share Document