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Hard Materials

  1. Andreas Zerr1,
  2. Heinz Eschnauer2,
  3. Erich Kny3

Published Online: 15 JUL 2012

DOI: 10.1002/14356007.a12_603.pub2

Ullmann's Encyclopedia of Industrial Chemistry

Ullmann's Encyclopedia of Industrial Chemistry

How to Cite

Zerr, A., Eschnauer, H. and Kny, E. 2012. Hard Materials. Ullmann's Encyclopedia of Industrial Chemistry. .

Author Information

  1. 1

    Laboratoire des Sciences des Procédés et des Matériaux - CNRS, Villetaneuse, France

  2. 2

    Plasma-Technik AG, Wohlen, Switzerland

  3. 3

    Metallwerk Plansee GmbH, Reutte, Austria

Publication History

  1. Published Online: 15 JUL 2012

Chemistry Terms

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Abstract

The article contains sections titled:

1.Introduction
1.1.Hardness Measurement (Overview)
1.2.Classification of Hard Materials
1.2.1.Occurrence
1.2.2.Appearance
1.2.3.Electrical Conductivity
1.2.4.Composition and Thermal Stability in Air
2.Nonmetallic Hard Materials
2.1.Diamond
2.2.Cubic Boron Nitride (c-BN)
2.3.Silicon Nitrides
2.4.Transition Metal Nitrides MxNx+1
2.5.Silicon Carbide
2.6.Alumina
2.7.Cermets
3.Metallic Hard Materials (Cemented Carbides)
3.1.Production
3.1.1.Raw Materials
3.1.2.Powder Batch Manufacturing
3.1.3.Pressing and Forming
3.1.4.Sintering
3.1.5.Machining
3.1.6.Coating
3.1.7.Testing and Quality Control
3.2.Commercial Grades
3.3.Properties
3.4.Uses
3.5.Economic Aspects
3.6.Toxicology

Hard materials are solid substances exhibiting a high resistance towards plastic (irreversible) deformation or damage of their surface by scratching (Mohs or Martens scale), grinding (Rosiwal method) or indentation (Brinell, Rockwell, Shore, Vickers, or Knoop testing). Some of them occur in nature but the majority is synthetic. They are also classified according to their appearance, electric conductivity, and chemical composition which defines their thermal stability in air. This article gives an overview of the synthesis routes, properties, and fields of application of the most important nonmetallic and metallic hard materials. A few recently discovered hard compounds are briefly introduced. Finally, the family of cemented carbides is discussed in more detail, which is broadly used today for cutting of ferrous alloys, in forming equipment, mining industry, and wear resistant components.