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英语翻译
The important thermal properties to materials are:
.Heat resistance ,the ability of a material to remain atable with changes in temperature .Ceramic materials have high resistance ratings .
.Thermal conductivity ,the ability of a material to transfer heat energy along its lwngth ,width ,or thickness .The rate of heat transfer for a material is called its coefficient of thermal conductivity.Metals have high coefficients of themal conductivity.Ceramics and polymers have low conductivity rates .they are therefore good heat insulators .
Thermal expansion,the rate of size change per unit of heat applied.Almost all engineering materials expand as they are heated .The rate of expansion is called the coefficient of linear expansion .The rate of expansion varies greatly among materials.
The varying rates of thermal expansion are the basis of the bimetal thermostat .The metal stripe of the thermostat have greatly different thermal expansion coefficients .When they are the other strip .This causes the strips to bend and touch the contact point .This action closes an electric circuit which could start a furnace ,turn on a cooling fan ,or light a warning light.
Electric and magnetic properties
Electrical and magnetic properties are similar .The electrical properties describe the behavior of a material carrying an electrical current .Magnetic properties involve the behavior of materials in an electromagnetic field .These properties include :
.Electrical conductivity the ability to conduct an electric current .Engineering materials are classified as conductors and insulators .Other materials are called semiconductors and are the foundation of the computer and data processing industry.
The opposite of electrical conductivity is electrical resistivity .If resistivity is an important property ,it is often discussed as the dielectric property or strength.The dielectric strength is a specific measure of a material's electrical insulating qualities .Metals generally are considered considered conductors of electricity while ceramics and polymers are insulators .
.Magnetic properties the ability to be magnetized by an external electromagnetic force .Materials with high magnetic properties are said to be permeable or have high permeability .Iron ,nickel ,and cobalt which are called ferromagnetic materials have high permeability.They are easily magnetized .
The important thermal properties to materials are:
.Heat resistance ,the ability of a material to remain atable with changes in temperature .Ceramic materials have high resistance ratings .
.Thermal conductivity ,the ability of a material to transfer heat energy along its lwngth ,width ,or thickness .The rate of heat transfer for a material is called its coefficient of thermal conductivity.Metals have high coefficients of themal conductivity.Ceramics and polymers have low conductivity rates .they are therefore good heat insulators .
Thermal expansion,the rate of size change per unit of heat applied.Almost all engineering materials expand as they are heated .The rate of expansion is called the coefficient of linear expansion .The rate of expansion varies greatly among materials.
The varying rates of thermal expansion are the basis of the bimetal thermostat .The metal stripe of the thermostat have greatly different thermal expansion coefficients .When they are the other strip .This causes the strips to bend and touch the contact point .This action closes an electric circuit which could start a furnace ,turn on a cooling fan ,or light a warning light.
Electric and magnetic properties
Electrical and magnetic properties are similar .The electrical properties describe the behavior of a material carrying an electrical current .Magnetic properties involve the behavior of materials in an electromagnetic field .These properties include :
.Electrical conductivity the ability to conduct an electric current .Engineering materials are classified as conductors and insulators .Other materials are called semiconductors and are the foundation of the computer and data processing industry.
The opposite of electrical conductivity is electrical resistivity .If resistivity is an important property ,it is often discussed as the dielectric property or strength.The dielectric strength is a specific measure of a material's electrical insulating qualities .Metals generally are considered considered conductors of electricity while ceramics and polymers are insulators .
.Magnetic properties the ability to be magnetized by an external electromagnetic force .Materials with high magnetic properties are said to be permeable or have high permeability .Iron ,nickel ,and cobalt which are called ferromagnetic materials have high permeability.They are easily magnetized .
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