Simple Fabrication and Carrier Type Modification of Semi-Conductive C/Al2O3 Composites by Powder Mixtures and Pulsed Electric Current Sintering

2021 ◽  
Author(s):  
Huu Hien Nguyen ◽  
Yunzi Xin ◽  
Takashi Shirai
Keyword(s):  
Electrical Properties ◽  
Electric Current ◽  
Powder Mixture ◽  
Ceramic Composites ◽  
Homogeneous Distribution ◽  
Polycarboxylic Acid ◽  
Pulsed Electric Current ◽  
Conventional Sintering ◽  
Conductive Ceramics ◽  
Carbon Fillers

Abstract Semi-conductive C/Al2O3 ceramic composites were successfully fabricated by a pretty simple approach, combining a powder mixture process and pulsed electric current sintering. In order to obtain homogeneous distribution of carbon contents, popular polymers were used as carbon fillers to mix with Al2O3 powder by a wet ball milling step. The sintering was conducted by pulsed electric current sintering without any special requirement of the reductive environment like in conventional sintering. Density of bulk bodies, states of carbon contents after sintering and the electrical properties were analyzed in this study. Although the density of sintered bodies and their electrical properties were not superior, those characteristics of C/Al2O3 ceramic composites in this study were still comparatively high among semi-conductive ceramics. Especially, the carrier type of semi-conductive C/Al2O3 composites could be modified easily by adding polycarboxylic acid (PCA) in the powder mixture as a dispersant.

scholarly journals The Effect of TiC Additive on Mechanical and Electrical Properties of Al2O3 Ceramic

2018 ◽  
Vol 8 (12) ◽  
pp. 2385 ◽  
Author(s):  
Sergey Grigoriev ◽  
Marina Volosova ◽  
Pavel Peretyagin ◽  
Anton Seleznev ◽  
Anna Okunkova ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Electrical Properties ◽  
Electrical Discharge Machining ◽  
Ceramic Composites ◽  
Homogeneous Distribution ◽  
Second Phase ◽  
Mechanical And Electrical Properties ◽  
Plasma Sintering ◽  
Cutting Inserts ◽  
Materials Used

In this study the influence of TiC content on the mechanical and electrical properties of Al2O3-TiC composites containing 30 and 40 vol.% TiC were investigated. The Vickers hardness and fracture toughness of the composites increased with the addition of TiC phase. The composite with 40 vol.% TiC showed the highest flexural strength (687 ± 39 MPa), fracture toughness (7.8 ± 0.4 MPa·m1/2) and hardness (22.3 ± 0.3 GPa) with a homogeneous distribution of the second phase within the ceramic matrix. Besides enhanced mechanical properties, it was found that ceramic composites with more than 30 vol.% TiC fabricated by the spark plasma sintering possess sufficient electrical conductivity for electrical discharge machining as well. Therefore, they do not limit the flexibility of the shape, and any intricate parts can be easily made with these composites which can be recommended for the production of cutting inserts in the tools for machining of superhard hardened steels, hard-to-machine materials, composites and other materials used in mechanical engineering.

Pulsed electric current sintering of electrically conductive ceramics

2008 ◽  
Vol 43 (19) ◽  
pp. 6435-6440 ◽  
Author(s):  
K. Vanmeensel ◽  
S. G. Huang ◽  
A. Laptev ◽  
S. A. Salehi ◽  
A. K. Swarnakar ◽  
...  
Keyword(s):  
Electric Current ◽  
Electrically Conductive ◽  
Pulsed Electric Current ◽  
Conductive Ceramics

Sapphire/Nd:YAG composite by pulsed electric current bonding for high-average-power lasers

2018 ◽  
Vol 43 (13) ◽  
pp. 3065 ◽  
Author(s):  
Hiroaki Furuse ◽  
Yuki Koike ◽  
Ryo Yasuhara
Keyword(s):  
Electric Current ◽  
Average Power ◽  
High Average Power ◽  
Pulsed Electric Current

Pulsed Electric Current Sintered Cr2O3-rGO Composites

2016 ◽  
Vol 721 ◽  
pp. 419-424
Author(s):  
M. Erkin Cura ◽  
Vivek Kumar Singh ◽  
Panu Viitaharju ◽  
Joonas Lehtonen ◽  
Simo Pekka Hannula
Keyword(s):  
Fracture Toughness ◽  
Graphene Oxide ◽  
Electric Current ◽  
Chromium Oxide ◽  
High Hardness ◽  
High Wear Resistance ◽  
Carbide Formation ◽  
Indentation Fracture ◽  
Pulsed Electric Current ◽  
Indentation Fracture Toughness

Chromium oxide is a promising material for applications where excellent corrosion resistance, high hardness, and high wear resistance are needed. However, its use is limited because of low fracture toughness. Improvement of fracture toughness of chromium oxide while maintaining its afore mentioned key properties is therefore of high interest. In this communication we study the possibility of increasing the toughness of pulsed electric current sintered (PECS) chromium oxide by the addition of graphene oxide (GO). The indentation fracture toughness was improved markedly with the addition of graphene oxide. Materials prepared by direct chemical homogenization had better fracture toughness. In composites with 10 vol.% GO piling of thin graphene oxide layers resulted in the formation of graphite layers between Cr2O3 and in carbide formation, which were observed to be the main reasons for the degradation of the mechanical properties. The distribution of graphene oxide was more homogeneous, when the GO amount was 0.1 vol.% and the formation of graphitic layers were avoided due to lesser amount of GO as well as ultrasonic treatment following the ball milling.

Sign in / Sign up

Export Citation Format

Share Document