scholarly journals Mechanical properties of phase-pure bulk Ta4AlC3 prepared by spark plasma sintering and subsequent heat treatment

2021 ◽  
Vol 15 (3) ◽  
pp. 211-218
Author(s):  
Guobing Ying ◽  
Cong Hu ◽  
Lu Liu ◽  
Cheng Sun ◽  
Dong Wen ◽  
...  

High-purity and bulk Ta4AlC3 ceramics were successfully fabricated by spark plasma sintering (SPS) and subsequent heat treatment, using the raw materials including TaC and Ta2AlC powders. These raw materials were first synthesized by self-propagation high temperature synthesis from elements tantalum, aluminium and carbon black powders, followed by pressure-less sintering. The as-fabricated bulk Ta4AlC3 was relatively stable when subjected to heat treatment at elevated temperature of 1500?C. Moreover, prolonging the heat treatment time resulted in bigger grain sizes and higher densities of the Ta4AlC3. The flexural strength and the fracture toughness of the Ta4AlC3 fabricated by SPS were found to be 411MPa and 7.11MPa?m1/2, respectively. After the heat treatment at 1500?C for 8 h, the flexural strength and the fracture toughness of the Ta4AlC3 could reach 709MPa and 9.23MPa?m1/2, respectively. The special structural characteristics of the ternary ceramics and the increase of density after the heat treatment are the main reasons for the variation in mechanical properties of ternary ceramics.

Author(s):  
Shufeng Li ◽  
Hiroshi Izui ◽  
Michiharu Okano

This paper discusses the dependence of the mechanical properties and microstructure of sintered hydroxyapatite (HA) on the sintering temperature and pressure. A set of specimens was prepared from as-received HA powder and sintered by using a spark plasma sintering (SPS) process. The sintering pressures were set at 22.3MPa, 44.6MPa, and 66.9MPa, and sintering was performed in the temperature range from 800°Cto1000°C at each pressure. Mechanisms underlying the interrelated temperature-mechanical and pressure-mechanical properties of dense HA were investigated. The effects of temperature and pressure on the flexural strength, Young’s modulus, fracture toughness, relative density, activation energy, phase stability, and microstructure were assessed. The relative density and grain size increased with an increase in the temperature. The flexural strength and Young’s modulus increased with an increase in the temperature, giving maximum values of 131.5MPa and 75.6GPa, respectively, at a critical temperature of 950°C and 44.6MPa, and the fracture toughness was 1.4MPam1∕2 at 1000°C at 44.6MPa. Increasing the sintering pressure led to acceleration of the densification of HA.


2016 ◽  
Vol 697 ◽  
pp. 188-192
Author(s):  
Jia Xin An ◽  
Wen Dong Xue ◽  
Feng Rui Zhai ◽  
Ruo Meng Xu ◽  
Jia Lin Sun

BN-Si3N4 composite ceramic wave-transparent materials with excellent mechanical properties were prepared by spark plasma sintering (SPS) using h-BN and α-Si3N4 powders as raw materials, Al2O3 and Y2O3 as sintering aids. The influence of sintering pressure on density and mechanical properties of BN-Si3N4 composite ceramics were studied. The phases were observed by X-ray diffraction (XRD), and the microstructures were identified by scanning electron microscopy (SEM). The results showed that with the sintering pressure increases, the relative density, bending strength and fracture toughness of the composite ceramics were significantly increased, and the porosity decreased rapidly. The effects of pressure on the properties of the composite ceramics was not significant at >40MPa, so 40MPa is optimal for the composite ceramics to gain good overall performance, i.e. the relative density was 89.1%, the porosity was 2.3%, the bending strength reached 215.4 MPa, and the fracture toughness was 3.1/MPa·m1/2.


2009 ◽  
Vol 631-632 ◽  
pp. 413-423 ◽  
Author(s):  
Shu Feng Li ◽  
Hiroshi Izui ◽  
Michiharu Okano ◽  
Wei Hua Zhang ◽  
Taku Watanabe

TZP-3Y20A/HA composites with addition of different volume fraction of hydroxyapatite (HA) were fabricated successfully using spark plasma sintering (SPS). The densification behavior and mechanical properties of composites are investigated as a function of sintering temperature and HA content respectively. The density of TZP-3Y20A composite increases steadily with temperature and a maximum value of 97.8% is obtained after sintering at 1400°C. Sintering the TZP-3Y20A/HA composites at 1400°C led to the decomposition of HA in the samples. Flexural strength, fracture toughness and Vickers hardness values increase with increasing sintering temperature, show decrease trend with increasing of HA content at the same temperature. They compared well with densities obtained at different sintering temperature. The maximum flexural strength, fracture toughness and Vickers hardness of 967.1 MPa, 5.27 MPam1/2 and 13.26 GPa were achieved for TZP-3Y20A composite respectively. Flexural strength, fracture toughness and Vickers hardness values of TZP-3Y20A/HA composite fell within the value range of dense HA and of TZP-3Y20A composite.


2005 ◽  
Vol 287 ◽  
pp. 335-339 ◽  
Author(s):  
Kyeong Sik Cho ◽  
Kwang Soon Lee

Rapid densification of the SiC-10, 20, 30, 40wt% TiC powder with Al, B and C additives was carried out by spark plasma sintering (SPS). In the present SPS process, the heating rate and applied pressure were kept at 100°C/min and at 40 MPa, while the sintering temperature varied from 1600-1800°C in an argon atmosphere. The full density of SiC-TiC composites was achieved at a temperature above 1800°C by spark plasma sintering. The 3C phase of SiC in the composites was transformed to 6H and 4H by increasing the process temperature and the TiC content. By tailoring the microstructure of the spark-plasma-sintered SiC-TiC composites, their toughness could be maintained without a notable reduction in strength. The strength of 720 MPa and the fracture toughness of 6.3 MPa·m1/2 were obtained in the SiC-40wt% TiC composite prepared at 1800°C for 20 min.


2020 ◽  
Author(s):  
Guangqi He ◽  
Rongxiu Guo ◽  
Meishuan Li ◽  
Yang Yang ◽  
Linshan Wang ◽  
...  

Abstract In this paper, short-carbon-fibers (Csf) reinforced Ti3SiC2 matrix composites (Csf/Ti3SiC2, the Csf content was 0, 2, 5 and 10 vol.%) were fabricated by spark-plasma-sintering (SPS) using Ti3SiC2 powders and Csf as starting materials at 1300 oC. The effects of Csf addition on the phase compositions, microstructures and mechanical properties (including hardness, flexural strength and fracture toughness) of Csf/Ti3SiC2 composites were investigated. The Csf, with a bi-layered transition layers, i.e. TiC and SiC layer, were homogeneously distributed in the as-prepared Csf/Ti3SiC2 composites. With the increase of Csf content, the fracture toughness of Csf/Ti3SiC2 composites increased, but the flexural strength decreased, while the Vickers hardness decreased initially then increased steadily when the Csf content was higher than 2 vol.%. These changed performances could be attributed to the introduction of Csf and the formation of much stronger interfacial phases.


2019 ◽  
Vol 64 (2) ◽  
pp. 265-270
Author(s):  
Andrea Balla ◽  
János Moczó ◽  
Zoltán Károly

Ni0,4Co0,2Zn0,4Fe2O4 spinel ferrites have been synthesized by precipitation method from an aqueous solution and bulk samples were fabricated by Spark Plasma Sintering (SPS) to investigate the microstructure and the mechanical properties. Although SPS is considered as a rapid compaction technique, its application is uncommon for ferrites due to reactions occurring between the graphite die and the ferrite powder at elevated temperature. In our tests this problem was circumvented by an alumina film applied on the die. We found that both chemical and phase composition could be retained in the sintered specimens after sintering. In addition, they exhibited improved mechanical properties in terms of hardness (10 GPa) and fracture toughness (2.7 MPa · m−1/2) as compared to conventionally sintered reference samples.


2014 ◽  
Vol 602-603 ◽  
pp. 380-383
Author(s):  
Chao He ◽  
Xiao Fei Shi ◽  
Xin Yan Yue ◽  
Jiang Jun Wang ◽  
Hong Qiang Ru

SiAlON-cBN composites with different contents of cBN were consolidated by spark plasma sintering (SPS) at 1450°C using Y2O3, B2O3 and Al as additives. The effect of cBN content on the density, phase compositions, microstructures and mechanical properties of β-SiAlON-cBN composites was investigated. With increasing the cBN content, the density and hardness of β-SiAlON-cBN composites decreased. Fracture toughness could increase thanks to the crack deflection resulted from the cBN particles. For β-SiAlON-10 wt% cBN composites, the optimum hardness and highest relative density were 13 GPa and 96.4 %, respectively. For β-SiAlON-40 wt% cBN composites, the highest fracture toughness was KIC = 5.3 MPa∙m1/2.


2014 ◽  
Vol 13 (1) ◽  
Author(s):  
Eszter Bódis ◽  
Orsolya Tapasztó ◽  
Zoltán Károly ◽  
Péter Fazekas ◽  
Szilvia Klébert ◽  
...  

AbstractMulitlayer graphene reinforced silicon nitride composites were prepared by spark plasma sintering to investigate the effect of the graphene addition on mechanical properties. The composites contained multilayer graphene (MLG) in various (0, 1, 3 and 5 wt%) content. Significantly higher fracture toughness of 8.0 MPa m


Sign in / Sign up

Export Citation Format

Share Document