Electrical Discharge Machining of Alumina-Zirconia-TiC Composites with Varying Zirconia Content

2013 ◽  
Vol 554-557 ◽  
pp. 1916-1921 ◽  
Author(s):  
Richard Landfried ◽  
Frank Kern ◽  
Rainer Gadow
Keyword(s):  
Electrical Discharge ◽  
Bending Strength ◽  
High Hardness ◽  
High Strength ◽  
Ceramic Composites ◽  
Matrix Composition ◽  
Pure Alumina ◽  
Electrically Conductive ◽  
Pure Zirconia ◽  
Strength And Toughness

Ceramic injection molding (CIM) or extrusion requires molds and dies with high hardness to reduce tool wear which occurs due to processing of highly abrasive ceramic compounds. Besides the wear resistance high strength and toughness are necessary for mold materials to withstand the loads during application. Recent work of the authors has shown the high potential of electrical discharge machinable ceramic composites based on oxide ceramic matrices for high wear applications. The use of alumina zirconia composites (AZC) as matrix for electrically conductive composites enables the combination of high hardness of alumina and high strength and toughness of zirconia in order to customize the properties of the mold material. This study focuses on development of ED machinable AZCs with addition of 24 vol.-% titanium carbide as electrically conductive phase. The composition of the matrix was varied from pure alumina to pure zirconia in 5 steps. Disks for mechanical and electrical characterization and electric discharge machining experiments were manufactured by hot pressing. Results show that hardness, strength and toughness can be almost linearly correlated to composition from pure alumina matrix with a 4-point bending strength of 430 MPa, a hardness of 2250 HV10 and a toughness of 3.7 MPa√m to pure zirconia matrix with 1020 MPa bending strength, 1490 HV10 and a toughness of 5.9 MPa√m. Variation of matrix composition also leads to significantly different EDM characteristics. The material removal rate shows a maximum at 19 vol.-% zirconia and 58 vol.-% alumina while surface roughness of the machined composites decreases significantly with increasing zirconia amount. SEM and EDX analysis were made to identify removal mechanisms of each ceramic matrix phase. It was found that alumina tends to be removed by vaporization due to electrical discharges. Zirconia, which has a higher melting and vaporization point than alumina melts during the formation of the plasma channel. Zirconia cannot be removed in total from the surface but forms a smooth and compact amorphous layer of resolidified material on both sample and electrode.

scholarly journals Mechanical Properties and Electrical Discharge Machinability of Alumina-10 vol% Zirconia-28 vol% Titanium Nitride Composites

Ceramics ◽  
2020 ◽  
Vol 3 (2) ◽  
pp. 199-209 ◽  
Author(s):  
Andrea Gommeringer ◽  
Frank Kern
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Composite Material ◽  
Titanium Nitride ◽  
Electrical Discharge ◽  
Fracture Resistance ◽  
High Strength ◽  
Electrically Conductive ◽  
Material Hardness ◽  
Ceramic Components

Electrical discharge machinable ceramics provide an alternative machining route independent on the material hardness which enables manufacturing of customized ceramic components. In this study a composite material based on an alumina/zirconia matrix and an electrically conductive titanium nitride dispersion was manufactured by hot pressing and characterized with respect to microstructure, mechanical properties and ED-machinability by die sinking. The composites show a combination of high strength of 700 MPa, hardness of 17–18 GPa and moderate fracture resistance of 4.5–5 MPa√m. With 40 kS/m the electrical conductivity is sufficiently high to ensure ED-machinability.

Preparation and Characterization of Reaction Sintering B4C/SiC Composite Ceramic

2014 ◽  
Vol 602-603 ◽  
pp. 536-539
Author(s):  
Hai Bin Sun ◽  
Yu Jun Zhang ◽  
Qi Song Li
Keyword(s):  
Fracture Toughness ◽  
High Performance ◽  
Bending Strength ◽  
Carbon Sources ◽  
High Hardness ◽  
High Strength ◽  
Composite Ceramic ◽  
High Fracture Toughness ◽  
Reaction Sintering ◽  
High Fracture

High hardness, high strength, high fracture toughness and low density are required for novel bulletproof materials. B4C/SiC composite ceramic is one of the most potential candidates. In this study, B4C/SiC composite ceramic was prepared by reaction sintering. The influence of B4C content, species and content of carbon, sintering temperature on the mechanical properties of B4C/SiC composite ceramic were studied. A high performance B4C/SiC composite ceramic was sintered at 1750°C for 30 min. Phenolic resin and carbon black were both chosen as carbon sources, whose favorable contents were 10wt%, 5wt%, respectively. The density of sintered bodies reduces with B4C content increases. To some extent, fracture toughness, bending strength improve initially and then deteriorate with the increase of B4C content whose optimal amount is 30wt%. The optimal fracture toughness and bending strength of the B4C/SiC composite ceramic are 5.07MPa·m1/2 and 487MPa, respectively. Meanwhile, the Viker-hardness of the sintered body is 30.2GPa, the density is as low as 2.82g/cm3.

Preparation and Characterization of Fe/SiC Ceramic-Metal Composites

2010 ◽  
Vol 434-435 ◽  
pp. 66-68 ◽  
Author(s):  
Zhong Sheng Liu ◽  
Gang Shao ◽  
De Liang Chen ◽  
Rui Zhang
Keyword(s):  
Bending Strength ◽  
Low Cost ◽  
High Hardness ◽  
High Strength ◽  
Precipitation Method ◽  
High Wear Resistance ◽  
Matrix Composites ◽  
Composite Powders ◽  
Pressing Method ◽  
Sic Composites

SiC is a perfect reinforced material, characteristic of high hardness, high wear- and corrosion-resistant property, and low cost. SiC-reinforced iron-matrix composites show high wear resistance, high hardness, high inflexibility and high strength, with wide applications as superior wear-resistant and high temperature materials. This paper reported a heterogeneous precipitation method to coat SiC with copper particles. The vacuum hot-pressing method was used to sinter the Fe/SiC composites with Cu-coated SiC powders. The techniques of XRD and SEM were used to characterize the compositions and microstructures of the samples. The Archimedes method was used to test the density. The results showed that SiC and Cu were homogeneously mixed in the composite powders obtained by the heterogeneous deposition method, and that the composites with 5wt% of SiC (Cu) obtained at 950°C have a high relative density of 96%, a high hardness of 4121 MPa and a high bending strength of 646 MPa. The enhanced properties of Fe/SiC composites could result from the improved interfacial consistency by using Cu-coated SiC powders, which could inhibit some adverse interfacial reactions.

Electrically Conductive and Wear Resistant Si3N4-Based Composites with TiC0.5N0.5 Particles for Electrical Discharge Machining

2005 ◽  
Vol 492-493 ◽  
pp. 27-32 ◽  
Author(s):  
Dongtao Jiang ◽  
Jef Vleugels ◽  
Omer Van der Biest ◽  
Wei Dong Liu ◽  
Raf Verheyen ◽  
...  
Keyword(s):  
Hot Pressing ◽  
Electrical Discharge ◽  
Material Removal ◽  
Bending Strength ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Strong Anisotropy ◽  
Electrically Conductive ◽  
Wear Resistant ◽  
Lower Material

Electrically conductive and wear resistant Si3N4-based composites were developed in order to facilitate electrical discharge machining (EDM). The microstructural and mechanical properties of Si3N4-based composites with different amounts of TiC0.5N0.5, fabricated by hot pressing at 1650°C for 1 hour, are investigated and evaluated. The hardness of the micron-sized TiC0.5N0.5 powder based composites increased with increasing TiC0.5N0.5 content from 20 up to 40 vol. %, whereas the bending strength decreased. The fracture toughness reached a maximum at 30 vol. % TiC0.5N0.5 and exhibits a strong anisotropy with respect to the hot-pressing direction. The EDM behaviour of the composites is strongly influenced by the TiC0.5N0.5 content. The composites with a higher TiC0.5N0.5 content have a lower material removal rate but a better surface quality.

High Strength, Electrically Conductive Pore-free TiO2 Ceramics made by Hot Isostatic Pressing

1997 ◽  
Vol 12 (4) ◽  
pp. 1056-1061 ◽  
Author(s):  
Yukio Kishi ◽  
Katsuhiko Ogura ◽  
Kiichiro Kamata ◽  
Hidetoshi Saitoh ◽  
Keizo Uematsu
Keyword(s):  
High Purity ◽  
Single Phase ◽  
Bending Strength ◽  
Specific Resistance ◽  
Semiconductor Industry ◽  
Hot Isostatic Pressing ◽  
Fine Powder ◽  
High Strength ◽  
Production Equipment ◽  
Electrically Conductive

A high-purity, single-phase TiO2 ceramic with high density, strength, and electrical conduction was developed as a key structural material for the production equipment of semiconductors. Green bodies were made of high purity rutile TiO2 of very fine powder. They were sintered in air at 1200 °C for 2 h and then were hot isostatically pressed (HIPed) in argon at 1000 °C, 150 MPa for 2 h. HIPed TiO2 ceramics were found to be electrically conductive and pore free. Their relative density, specific resistance, and bending strength were 100%, 1 Ω ·cm, and 300 MPa, respectively. No strength degradation was found to the temperature up to 1000 °C. This material has high potential for use as electrically conductive structure materials in the semiconductor industry.

scholarly journals Bioinspired, graphene-enabled Ni composites with high strength and toughness

2019 ◽  
Vol 5 (5) ◽  
pp. eaav5577 ◽  
Author(s):  
Yunya Zhang ◽  
Frederick M. Heim ◽  
Jamison L. Bartlett ◽  
Ningning Song ◽  
Dieter Isheim ◽  
...  
Keyword(s):  
High Performance ◽  
2D Materials ◽  
High Hardness ◽  
High Strength ◽  
Limited Resources ◽  
Matrix Composites ◽  
Multiple Length Scales ◽  
Brick And Mortar ◽  
Hierarchical Architectures ◽  
Strength And Toughness

Nature’s wisdom resides in achieving a joint enhancement of strength and toughness by constructing intelligent, hierarchical architectures from extremely limited resources. A representative example is nacre, in which a brick-and-mortar structure enables a confluence of toughening mechanisms on multiple length scales. The result is an outstanding combination of strength and toughness which is hardly achieved by engineering materials. Here, a bioinspired Ni/Ni3C composite with nacre-like, brick-and-mortar structure was constructed from Ni powders and graphene sheets. This composite achieved a 73% increase in strength with only a 28% compromise on ductility, leading to a notable improvement in toughness. The graphene-derived Ni-Ti-Al/Ni3C composite retained high hardness up to 1000°C. The present study unveiled a method to smartly use 2D materials to fabricate high-performance metal matrix composites with brick-and-mortar structure through interfacial reactions and, furthermore, created an opportunity of developing advanced Ni-C–based alloys for high-temperature environments.

Titanium Carbide Reinforced Composite Tool Ceramics Based on Alumina

2010 ◽  
Vol 65 ◽  
pp. 50-55
Author(s):  
Magdalena Szutkowska ◽  
Barbara Smuk ◽  
Marek Boniecki
Keyword(s):  
Fracture Toughness ◽  
Wear Resistance ◽  
Titanium Carbide ◽  
High Hardness ◽  
Ceramic Composites ◽  
Critical Stress Intensity Factor ◽  
Pure Alumina ◽  
Reinforced Composite ◽  
Composite Tool ◽  
Tool Ceramics

The present study reports some preliminary results obtained by reinforcing Al2O3-10 wt% ZrO2 (partially stabilized with Y2O3 -Y5 and monoclinic phase m-ZrO2) composite with TiC phase in amount of 5 wt %. Ceramic composites were prepared on the basis submicro and nano scale trade powders. Apparent density, porosity, Vicker’s hardness, Young’s modulus and fracture toughness (KIC) were determined. Wear resistance (Vn) very important property for tool ceramics was specified by the speed of mass lost. Scanning electron microscopy (SEM) to observation of the fracture surface microstructure was used. The titanium carbide reinforced composite tool ceramics based on alumina exhibit high hardness, fracture toughness (critical stress intensity factor KIC increase up to 5,2 MPa m1/2), high elastic moduli and higher wear resistance in related to pure alumina. Cutting tests confirm the high performance of these ceramic composites.

Fabrication and Hardening Treatment for SiC/AlN Ceramic Composites

2009 ◽  
Vol 620-622 ◽  
pp. 363-366
Author(s):  
Hai Yun Jin ◽  
Ying Li ◽  
Xiang Ya Jia ◽  
Guan Jun Qiao
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
High Hardness ◽  
Ceramic Composites ◽  
New Method ◽  
Composite Ceramics ◽  
Hardening Treatment ◽  
Sic Ceramic ◽  
Machinable Ceramic ◽  
Plasma Activated Sintering

In order to obtain machinable ceramic with high hardness and strong mechanical properties, the SiC/Al/h-BN Composite Ceramics were fabricated by a new method which prepared the machinable pre-sintered body by Plasma Activated Sintering (PAS) and increased it's mechanical properties after hardening treatment. The results showed that the machinability and density of the pre-sintered h-BN/Al/SiC ceramic composites were excellent, and after hardening treatment, the mechanical properties (hardness, bending strength and density) increased obviously.

Development of Trends and Methodologies for Shaping Ceramics by Electrical Discharge Machining: A Review

2019 ◽  
Author(s):  
Asif Rashid ◽  
Muhammad P. Jahan ◽  
Asma Perveen ◽  
Jianfeng Ma
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
High Hardness ◽  
High Strength ◽  
Ceramic Materials ◽  
Machining Process ◽  
Future Research ◽  
Great Resistance ◽  
Hard And Brittle Materials ◽  
Superior Corrosion Resistance

Abstract Ceramic materials possess excellent properties like high hardness, superior corrosion resistance and great resistance to wear. These materials are low in density and demonstrate high strength to wear ratio. There is an increasing need to machine these hard and brittle materials as they have various engineering applications. The distinguishing properties of ceramics do not allow them to be machined by conventional processes. Electrical discharge machining (EDM) is a non-conventional process and a viable option to machine and generate complex shapes in hard materials. EDM can be used on materials irrespective of its hardness and wear resistance as it is a non-contact machining process and no active force is applied between the workpiece and electrode during machining. As EDM requires the workpiece to be electrically conductive, machining ceramics by this process is a challenge. Alterations need to be carried out in order for insulating ceramics to be machined by this process. This paper discusses the basics of EDM process and its control parameters. A classification of ceramic materials based on their electrical conductivity is established and their relevance to the respective material removal mechanisms have been identified. Different approaches to successfully machine ceramics by EDM have been reviewed. The challenges and modifications of each method have been discussed. An outline and expectations for machining a particular ceramic material and its composites have been generated. Finally, the prospects of future research in this area have been identified.

The Manufacture of SiC Fiber Reinforced ΑI2O3 Coatings by Plasma Spraying

1996 ◽  
Author(s):  
H.-D. Steffens ◽  
M. Brune ◽  
E. Müller ◽  
R. Dittrich
Keyword(s):  
Plasma Spraying ◽  
Composite Coatings ◽  
High Strength ◽  
Ceramic Coatings ◽  
Ceramic Composites ◽  
Composite Powders ◽  
Pure Alumina ◽  
High Oxygen Content ◽  
Sic Fiber ◽  
Plasma Sprayed

Abstract Oftentimes, the application of bulk ceramics and ceramic coatings is limited by their poor fracture toughness and low strength. The mechanical properties of ceramics can be significantly improved by the incorporation of fibres, whiskers or particles of high strength, like SiC. Due to the high oxygen content of commercially available SiC fibers in combination with the elevated process temperatures, the SiC decomposes during plasma spraying. Therefore commercial SiC fibres were coated for temporary oxidation protection with C, TiN or Al2O3. By different agglomeration techniques using an organic binder SiC/Al2O3 composite powders were produced. Powder mixtures consisting of coated fibres and pure alumina as well as agglomerated powders have been successfully sprayed to form deposits. Recent results of the manufacture of SiC fibre-reinforced ceramic composites by plasma spray technology are presented. The properties of the composite coatings are compared to plasma sprayed pure alumina.

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