Novel Nontraditional High Alumina Ceramic Composite

Dynamic response and fracture of high strength boride/alumina ceramic composite were investigated by split Hopkinson pressure bar (SHPB) experiment in this paper. The compressive stress–strain curves and dynamic compression strength of the composites were tested. The surface’s microstructure of fractured composites were examined by using scanning electron microscope (SEM) to investigate the fracture mechanism. The results show that boride/alumina has high dynamic compressive strength and high Young’s modulus. The main fracture mode of the material is the fracture of the ceramic grains. The micro-voids and flaws, generated during the sintering and manufacturing of material and mechanical process of specimen, decrease the strength of the material because they provide the source of crack expansion when the material undergoes the dynamic loadings.

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Effect of MgO Nano Particle on Mechanical Property and Microstructure of ZTA Ceramic Composite

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.364.450 ◽

2011 ◽

Vol 364 ◽

pp. 450-454 ◽

Cited By ~ 1

Author(s):

Ahmad Zahirani Ahmad Azhar ◽

Mohamad Hasmaliza ◽

Manimaran Ratnam ◽

Zainal Arifin Ahmad

Keyword(s):

Mechanical Properties ◽

Mechanical Property ◽

Vickers Hardness ◽

Ceramic Composite ◽

Weight Percent ◽

Alumina Ceramic ◽

Nano Particle ◽

Microstructural Observation ◽

Hardness Property ◽

Zirconia Toughened Alumina

The mechanical properties and microstructure of zirconia-toughened-alumina ceramic composite doped with nanoparticle of MgO is investigated. The nanoMgO weight percent was varied from 0.3 wt % to 1.3 wt %. Each batch of composition was mixed using ultrasonic cleaner and mechanical stirrer, uniaxially pressed and sintered at 1600 °C for 4 h in pressureless conditions. Analysis of bulk density, Vickers hardness and microstructural observation has been carried out. Results of Vickers hardness increased linearly with addition of more nanoMgO until a certain composition. Maximum Vickers hardness obtained was 1740HV with 1.1 wt % MgO. Furthermore, microstructural observations show that the Al2O3 grain size depends on the particle size of MgO, and is directly related to its hardness property.

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Enhancement of Dry Sliding Tribological Characteristics of Perforated Zirconia Toughened Alumina Ceramic Composite Filled With Nano MoS2 in High Vacuum

Journal of Tribology ◽

10.1115/1.4048497 ◽

2020 ◽

Vol 143 (6) ◽

Author(s):

Kunal Ghosh ◽

Subhrojyoti Mazumder ◽

Harish Hirani ◽

Poulomi Roy ◽

Nilrudra Mandal

Keyword(s):

Ceramic Composite ◽

High Vacuum ◽

Ceramic Composites ◽

Alumina Ceramic ◽

Tribological Characteristics ◽

Dry Sliding ◽

Temperature Environment ◽

Zirconia Toughened Alumina ◽

Wear Tests ◽

High Temperature Environment

Abstract An innovative approach was adopted for fabricating zirconia toughened alumina (ZTA)-MoS2 self-lubricating ceramic composites with the inclusion of hydrothermally synthesized nano MoS2 through the micropores of perforated ZTA ceramics. This method avoided the exposure of MoS2 in high-temperature environment due to its in-sensitiveness during traditional sintering techniques. Different weight percentages (wt%: 0, 5, 10, and 15) of graphite were incorporated to produce porous ZTA ceramics with the help of cold press sintering followed by insertion of nano MoS2 into the matrices. Best tribological characteristics were obtained with 10 wt% graphite-ZTA-MoS2 specimen which offered an improvement of ∼66% in coefficient of friction (COF) and ∼96% in specific wear rate when dry sliding tests were carried out against silicon nitride (Si3N4) in high vacuum (5.0 × 10−4 mbar). Nano MoS2 was sheared off at the contacting interface during sliding under load which showed a good tribological characteristics of the composite. Delamination was found as the dominating wear mechanism in ZTA-MoS2 composites during wear tests.

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