Effect of Titania and Magnesia on the Physical Properties of Zirconia Toughened Alumina

2016 ◽  
Vol 840 ◽  
pp. 82-86
Author(s):  
Hanisah Manshor ◽  
Wan Muhammad Ihsan Wan Sabri ◽  
Abdul Wahid Ramli ◽  
Ahmad Zahirani Ahmad Azhar ◽  
Ezzat Chan Abdullah ◽  
...  
Keyword(s):  
Physical Properties ◽  
Ceramic Composite ◽  
High Hardness ◽  
Secondary Phase ◽  
Solubility Limit ◽  
Ceramic Composites ◽  
High Temperature Strength ◽  
Constant Weight ◽  
Weight Percentage ◽  
Zirconia Toughened Alumina

ZTA based ceramic composite system is widely accepted as cutting tools for many of these harder and wear resistant workpiece materials. This is due to their beneficial mechanical properties i.e. high temperature strength, high hardness and ability to maintain its cutting edge shape at higher temperatures. Although a lot of works have focused on the effect of various sintering additives on the ZTA ceramic system, the effect of Magnesia (MgO) and Titania (TiO2) on ZTA has not yet been studied. In this work, the physical properties of Zirconia Toughened Alumina (ZTA) ceramic composite with MgO and TiO2 as additives was investigated. The composition of TiO2 varied from 0 wt% to 3.5 wt% whereby other materials such as Al2O3, Yttria Stabilized Zirconia (YSZ) and MgO were kept at constant weight percentage. Sintered samples were then tested and analyzed by XRD, Vickers hardness and high precision densimeter to investigate phase content, hardness value and densification respectively. Results showed that the solubility limit of TiO2 in ZTA-MgO ceramic composites is at 2.0 wt%. Further addition of TiO2 resulted in the formation of secondary phase known as Zirconium titanium oxide (Zr0.35TiO0.65O2) which deteriorate the properties exhibited by ZTA-MgO-TiO2 ceramic composites.

scholarly journals Microstructure Characteristics of Ce-ZTA Ceramic Composites Obtained by Liquid Phase Sintering

2006 ◽  
Vol 530-531 ◽  
pp. 421-424
Author(s):  
Haine Beck ◽  
Maria do Carmo de Andrade Nono ◽  
Francisco Piorino Neto
Keyword(s):  
Ceramic Composite ◽  
Glassy Phase ◽  
Volume Fraction ◽  
Tetragonal Zirconia ◽  
Ceramic Composites ◽  
Liquid Phase Sintering ◽  
Scanning Electronic Microscopy ◽  
Powder Samples ◽  
Zirconia Toughened Alumina ◽  
Crystalline Matrix

Zirconia-toughened alumina (ZTA) ceramics with Ce-TZP (tetragonal zirconia polycrystalline doped with ceria) volume fraction on 33% were prepared with the addition.. The influence of glass infiltrated method was investigated. Coprecipitated Zr and Ce hydroxide mixture was obtained from ZrOCl2.8H2O and CeCl3. 7H2O aqueous solution. CeO2-ZrO2 calcinated powder was compacted and the compacted samples were sintered at 1180°C. Powder samples were characterized by scanning electronic microscopy (SEM), The volume fraction of each phase, the grains size and shapes, and the porosity were investigated with SEM. The relative density and shrinkage was investigate too. The results showed that the crystalline matrix was composed by SiO2 -B2O3-La2O3-Al2O3-Ce-TZP and revealed the important role played the glassy phase in the densification of this ceramic composite.

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

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.

Peridynamical Modelling of Nanoindentation in Ceramic Composites

2016 ◽  
Vol 254 ◽  
pp. 55-59 ◽  
Author(s):  
Tomasz Sadowski ◽  
Błażej Pankowski
Keyword(s):  
Ceramic Composite ◽  
Ceramic Composites ◽  
Intrinsic Stress ◽  
Stress Singularities ◽  
Continuum Approach ◽  
Two Phase ◽  
Brittle Solids ◽  
Complex Phenomena ◽  
Zirconia Toughened Alumina

Indentation in brittle solids involves many complex phenomena related to cleavage and contact, as well as intrinsic stress singularities, which are almost impossible to capture with traditional continuum approach and FEA at mesoscale. In case of a two-phase ceramic composite [1–3] the number of unknown material and interfacial constants, that have to be calibrated experimentally, increases rapidly [4, 5]. In this paper, nanoindentation in zirconia-toughened alumina (ZTA) is modelled using discrete (peridynamical) approach

Study on Mechanical Properties of Zirconia-Alumina Based Ceramics

2014 ◽  
Vol 625 ◽  
pp. 81-84 ◽  
Author(s):  
Kalaimani Markandan ◽  
Jit Kai Chin ◽  
Michelle T.T. Tan
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Surface Morphology ◽  
Physical Properties ◽  
Elemental Composition ◽  
Ceramic Composite ◽  
Ceramic Composites

This paper describes the characterisations of ceramic composites consisting of different compositions of alumina and zirconia. The material characterisations were performed from the aspects of densification, hardness and fracture toughness. The surface morphology and elemental composition of the composite were studied using SEM and EDX respectively. As for physical properties, the highest attainable hardness and fracture toughness were 11.35 GPa and 3.41 MPa m0.5respectively for ceramic composite consisted of 80 wt % Zr and 20 wt% Al. Sintering at 1150oC assisted in the densification of ceramics.

scholarly journals BORON CARBIDE BASED CERAMIC COMPOSITES HOT PRESSED WITH ALUMINIUM ADDITIVE

2020 ◽  
Vol 26 (2) ◽  
pp. 67-69
Author(s):  
Pavol Švec ◽  
Zuzana Gábrišová ◽  
Alena Brusilová ◽  
Ľubomír Čaplovič
Keyword(s):  
Ceramic Composite ◽  
Secondary Phase ◽  
Ceramic Composites ◽  
Additive Concentration ◽  
Sintering Additives ◽  
Average Value ◽  
Sintering Additive ◽  
Vacuum Atmosphere ◽  
Composite Samples

Ceramic composite materials consisting of B4C matrix and Al8B4C7 secondary phase were prepared by in situ reactive sintering of the initial powder mixture B4C-Al with concentration from 5 to 25 wt.% Al sintering additives. The composite samples were hot pressed at the temperature of 1850 °C, pressure of 35 MPa, for 15 min in a vacuum atmosphere. The portion of Al8B4C7 secondary phase increased from 3.3 to 22.1 wt.% when increasing the concentration of Al sintering additive from 5 to 25 wt.% Al. Significant improving of densification and mechanical properties was measured at increasing of Al sintering additive concentration from 5 to 10 wt.% Al. The highest average hardness of 28.74 GPa was achieved when adding 15 wt.% Al sintering additive. The fracture toughness increased with concentration of Al sintering additive in whole concentration range with the highest average value of 5.92 MPa.m1/2 at 25 wt.% Al sintering additives.

Effect of Cr2O3-TiO2 Addition on the Physical Properties of Zirconia Toughened Alumina

2016 ◽  
Vol 840 ◽  
pp. 34-38 ◽  
Author(s):  
Hanisah Manshor ◽  
Abdul Wahid Ramli ◽  
Ahmad Zahirani Ahmad Azhar ◽  
Ezzat Chan Abdullah ◽  
Zainal Arifin Ahmad
Keyword(s):  
Mechanical Properties ◽  
Physical Properties ◽  
Magnesium Oxide ◽  
Cerium Oxide ◽  
Vickers Hardness ◽  
Ceramic Composite ◽  
Powder Materials ◽  
Powder Mixtures ◽  
Cutting Insert ◽  
Zirconia Toughened Alumina

Zirconia toughened alumina (ZTA) has good mechanical properties and widely used in cutting insert application. Although the ZTA is well known of its good mechanical properties, its still can be improved in order to produce better properties. It can be done by adding additives as reinforcement such as magnesium oxide (MgO), cerium oxide (CeO), titania (TiO2) and chromia (Cr2O3). The effect of TiO2-Cr2O3 addition on the physical properties of ZTA were investigated in this study. The composition of TiO2 was varied from 0 wt% to 3.5 wt% while Cr2O3 was fixed at 5 wt%. The starting powder materials were mixed by wet mixing for 30 minutes in acetone. Then the powder mixtures were hydraulically pressed at 260 MPa. The green pellets were sintered at 1600°C for 1 hour using an electrical furnace in presureless condition. The results were characterized by XRD, density, and also Vickers hardness. The ZTA-Cr2O3-TiO2 ceramic composite achieved the highest density of 4.1 g/cm3 and Vickers hardness of 1919 HV prior to the addition of 2.0 wt% TiO2. Therefore, it can be decisively concluded that the addition of Cr2O3-TiO2 does affected the properties of ZTA.

Observation of solid-state reaction between a thin yttria film and a (0001) α-alumina substrate

1994 ◽  
Vol 52 ◽  
pp. 644-645
Author(s):  
J. R. Heffelfinger ◽  
C. B. Carter
Keyword(s):  
Electron Microscopy ◽  
Solid State ◽  
Solid State Reaction ◽  
Yttrium Aluminum Garnet ◽  
Secondary Phase ◽  
Ceramic Composites ◽  
Alumina Substrate ◽  
Transmission Electron ◽  
Alumina Fibers ◽  
Optical Applications

Transmission-electron microscopy (TEM), scanning-electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS) were used to investigate the solid-state reaction between a thin yttria film and a (0001) α-alumina substrate. Systems containing Y2O3 (yttria) and Al2O3 (alumina) are seen in many technologically relevant applications. For example, yttria is being explored as a coating material for alumina fibers for metal-ceramic composites. The coating serves as a diffusion barrier and protects the alumina fiber from reacting with the metal matrix. With sufficient time and temperature, yttria in contact with alumina will react to form one or a combination of phases shown by the phase diagram in Figure l. Of the reaction phases, yttrium aluminum garnet (YAG) is used as a material for lasers and other optical applications. In a different application, YAG is formed as a secondary phase in the sintering of AIN. Yttria is added to AIN as a sintering aid and acts as an oxygen getter by reacting with the alumina in AIN to form YAG.

UNITEMP HX

Alloy Digest ◽  
1964 ◽  
Vol 13 (5) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Base Material ◽  
Heat Treating ◽  
Operating Conditions ◽  
High Temperature Strength ◽  
Temperature Performance ◽  
Nickel Base

Abstract Unitemp-HX is a nickel-base material recommended for high temperature applications. It has outstanding oxidation resistance at high temperatures under most operating conditions, and good high-temperature strength. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness and creep. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ni-91. Producer or source: Universal Cyclops Steel Corporation.

REYNOLDS 390 and A390

Alloy Digest ◽  
1971 ◽  
Vol 20 (8) ◽  
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
High Hardness ◽  
Heat Treating ◽  
Silicon Alloys ◽  
Aluminum Silicon Alloys ◽  
Temperature Performance

Abstract REYNOLDS 390 and A390 are hypereutectic aluminum-silicon alloys having excellent wear resistance coupled with good mechanical properties, high hardness, and low coefficients of expansion. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fatigue. It also includes information on high temperature performance and corrosion resistance as well as casting, heat treating, and machining. Filing Code: Al-203. Producer or source: Reynolds Metals Company.

AMPCO 483

Alloy Digest ◽  
1978 ◽  
Vol 27 (4) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
Base Alloy ◽  
High Hardness ◽  
High Strength ◽  
Heat Treating ◽  
Good Resistance ◽  
Copper Base ◽  
Copper Base Alloy

Abstract AMPCO 483 is a copper-base alloy that can be used in the cast or wrought form. It provides high strength, high hardness, excellent resistance to corrosion and good resistance to fatigue and wear. It is well suited for service at temperatures up to 750 F and for applications such as pickling equipment, nuts and marine hardware. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as casting, forming, heat treating, machining, and joining. Filing Code: Cu-352. Producer or source: Ampco Metal Inc..

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