scholarly journals Self-Healing of SiC-Al2O3-B4C Ceramic Composites at Low Temperatures

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 652
Author(s):  
Baoguo Wang ◽  
Rong Tu ◽  
Yinglong Wei ◽  
Haopeng Cai
Keyword(s):  
Flexural Strength ◽  
Low Temperatures ◽  
Ceramic Composite ◽  
Ceramic Composites ◽  
Self Healing ◽  
Vickers Indentation ◽  
Crack Healing ◽  
Practical Applications ◽  
Plasma Sintering ◽  
Spark Plasma

Self-healing ceramics have been researched at high temperatures, but few have been considered at lower temperatures. In this study, SiC-Al2O3-B4C ceramic composite was compacted by spark plasma sintering (SPS). A Vickers indentation was introduced, and the cracks were healed between 600 °C and 800 °C in air. Cracks could be healed completely in air above 700 °C. The ceramic composite had the best healing performance at 700 °C for 30 min, recovering flexural strength of up to 94.2% of the original. Good crack-healing ability would make this composite highly useful as it could heal defects and flaws autonomously in practical applications. The healing mechanism was also proposed to be the result of the oxidation of B4C.

Preparation and Characterization of Mechanical Properties of Hydroxyapatite/Carbon Nanotube Laminated Ceramic Composites Consolidated by Spark Plasma Sintering

2018 ◽  
Vol 913 ◽  
pp. 466-472
Author(s):  
Ye Meng ◽  
Wen Jiang Qiang ◽  
Jing Qin Pang
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Flexural Strength ◽  
Spark Plasma Sintering ◽  
Strain Curve ◽  
Ceramic Composites ◽  
Stress Strain ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Stratified Structure

Laminated xCNTs-HAP/yCNTs-HAP ceramic composites were consolidated using a spark plasma sintering(SPS) technique at SPS temperature 900°C, pressure 40MPa and holding time 5min. The effect of carbon nanotubes content and thickness of each layer on mechanical properties of the composites was investigated. It was demonstrated that the stratified structure improvedthe flexural strength obviously. All the flexural strength of laminar compositewashigher than that of single CNTs-HAP ceramic, up to 112.4MPa. Since the matrix of each layer wereHAP, the difference liesonly in the content of carbon nanotubes, thus avoiding the common problem of the interlayer bonding in other layered composites with different materials. In order to characterize the toughness of the layered composite, the stress-strain curve was compared showingthat the existence of the stratified structure improved the stress-strain obviously.

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.

Spark plasma sintering of graphene reinforced zirconium diboride ultra-high temperature ceramic composites

2013 ◽  
Vol 39 (6) ◽  
pp. 6637-6646 ◽  
Author(s):  
Govindaraajan B. Yadhukulakrishnan ◽  
Sriharsha Karumuri ◽  
Arif Rahman ◽  
Raman P. Singh ◽  
A. Kaan Kalkan ◽  
...  
Keyword(s):  
High Temperature ◽  
Spark Plasma Sintering ◽  
Zirconium Diboride ◽  
Ceramic Composites ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Ultra High Temperature

Preparation and Characterization of Alumina based TiNn and SiCn Composites

2002 ◽  
Vol 740 ◽  
Author(s):  
Mats Carlsson ◽  
Mats Johnsson ◽  
Annika Pohl
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Grain Growth ◽  
Ceramic Composites ◽  
Processing Route ◽  
Nano Structure ◽  
Plasma Sintering ◽  
Water Based ◽  
Spark Plasma

ABSTRACTCeramic composites containing 2 and 5vol. % of nanosized commercially available TiN and SiC particles in alumina were prepared via a water based slurry processing route followed by spark plasma sintering (SPS) at 75 MPa in the temperature range 1200–1600°C. Some of the samples could be fully densified by use of SPS already after five minutes at 1200°C and 75 MPa. The aim was to control the alumina grain growth and thus obtain different nano-structure types. The microstructures have been correlated to some mechanical properties; e.g. hardness and fracture toughness.

Fabrication of MgO/Graphene Composites by Combustion Synthesis and Spark Plasma Sintering

2018 ◽  
Vol 281 ◽  
pp. 125-130
Author(s):  
Nan Lu ◽  
Jia Xi Liu ◽  
Gang He ◽  
Jiang Tao Li
Keyword(s):  
Mechanical Properties ◽  
Combustion Synthesis ◽  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Ceramic Composites ◽  
Combustion Reaction ◽  
Sintering Additive ◽  
Microstructure And Mechanical Properties ◽  
Plasma Sintering ◽  
Spark Plasma

MgO/Graphene ceramic composites were fabricated by combining combustion synthesis with spark plasma sintering. MgO/Graphene mixture powders were prepared by the combustion reaction between Mg powders and CO2 gas. Dense MgO/Graphene composites were fabricated by spark plasma sintering (SPS) using LiF as the sintering additive. The effect of the sintering temperature on microstructure and mechanical properties of the prepared MgO/Graphene ceramics was discussed. The sintering temperature of the MgO/Graphene mixture powders increased from 900°C to 1300°C. The highest density of 3.43g/cm3 and hardness of 2133MPa were obtained at 1100°C. Compared with monolithic MgO ceramics, the hardness of MgO/Graphene ceramics at the same sintering temperature was increased from 840MPa to 2133MPa.

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