4.1 Classes of Materials
If you stop for a moment and look around you, you will notice a
wide variety of materials, either artificially produced by humans or
naturally existing in nature. Both types can be categorized in particular classes to provide a better understanding of their similarities
and differences. In this book, we distinguish seven classes: metallic,
ceramic, polymeric, composite, electronic, biomaterials, and nanomaterials. However, as you will note, some materials have characteristics across various classes.
Metallic Materials
Metallic materials consist principally of one or more metallic elements, although in some cases small additions of nonmetallic
elements are present. Examples of metallic elements are copper,
nickel, and aluminum, whereas examples of nonmetallic elements are carbon, silicon, and nitrogen. When a particular metallic element dissolves well in one or more additional elements, the
mixture is called a metallic alloy. The best example of a metallic alloy
is steel, which is composed of iron and carbon. Metallic materials
exhibit metallic-type bonds and thus are good thermal and electrical conductors and are ductile, particularly at room temperature.
Ceramic Materials
Ceramic materials are composed of at least two different elements.
Among the ceramic materials, we can distinguish those that are predominantly ionic in nature (these consist of a mixture of metallic
elements and nonmetallic elements) and those that are covalent in
nature (which consist mainly of a mixture of nonmetallic elements).
87
Material Classes, Structure, and Properties
Chapter 4
Nanomaterials, Nanotechnologies and Design
Copyright 2009 Elsevier Ltd. All rights of reproduction in any form reserved.
If you stop for a moment and look around you, you will notice a
wide variety of materials, either artificially produced by humans or
naturally existing in nature. Both types can be categorized in particular classes to provide a better understanding of their similarities
and differences. In this book, we distinguish seven classes: metallic,
ceramic, polymeric, composite, electronic, biomaterials, and nanomaterials. However, as you will note, some materials have characteristics across various classes.
Metallic Materials
Metallic materials consist principally of one or more metallic elements, although in some cases small additions of nonmetallic
elements are present. Examples of metallic elements are copper,
nickel, and aluminum, whereas examples of nonmetallic elements are carbon, silicon, and nitrogen. When a particular metallic element dissolves well in one or more additional elements, the
mixture is called a metallic alloy. The best example of a metallic alloy
is steel, which is composed of iron and carbon. Metallic materials
exhibit metallic-type bonds and thus are good thermal and electrical conductors and are ductile, particularly at room temperature.
Ceramic Materials
Ceramic materials are composed of at least two different elements.
Among the ceramic materials, we can distinguish those that are predominantly ionic in nature (these consist of a mixture of metallic
elements and nonmetallic elements) and those that are covalent in
nature (which consist mainly of a mixture of nonmetallic elements).
87
Material Classes, Structure, and Properties
Chapter 4
Nanomaterials, Nanotechnologies and Design
Copyright 2009 Elsevier Ltd. All rights of reproduction in any form reserved.