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11 Cards in this Set
- Front
- Back
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Define density as a material property. |
Density is the weight per unit volume of a material. |
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What is the difference in melting characteristics between a pure metal element and an alloy metal? |
A pure metal element melts at one temperature (the melting point), while an alloy begins melting at a certain temperature called the solidus and finally completes the transformation to the molten state at a higher temperature called the liquidus. Between the solidus and liquidus, the metal is a mixture of solid and liquid. |
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Describe the melting characteristics of a noncrystalline material such as glass. |
In the heating of a noncrystalline material such as glass, the material begins to soften as temperature increases, finally converting to a liquid at a temperature defined for these materials as the melting point. |
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Define specific heat as a material property. |
Specific heat is defined as the quantity of heat required to raise the temperature of a unit mass of the material by one degree. |
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What is thermal conductivity as a material property? |
Thermal conductivity is the capacity of a material to transfer heat energy through itself by thermal movement only (no mass transfer). |
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Define thermal diffusivity. |
Thermal diffusivity is the thermal conductivity divided by the volumetric specific heat. |
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What are the important variables that affect mass diffusion? |
According to Fick's first law, mass diffusion depends on the diffusion coefficient of the material, which increases rapidly with temperature (so temperature could be listed as an important variable), concentration gradient, contact area, and time. |
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Define resistivity as a material property. |
Resistivity is the material's capacity to resist the flow of electric current. |
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Why are metals better conductors of electricity than ceramics and polymers? |
Metals are better conductors because of metallic bonding, which permits electrons to move easily within the metal. Ceramics and polymers have covalent and ionic bonding, in which the electrons are tightly bound to particular molecules. |
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What is dielectric strength as a material property? |
Dielectric strength is defined as the electrical potential required to break down the insulator per unit thickness. |
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What is an electrolyte? |
An electrolyte is an ionized solution capable of conducting electric current by movement of the ions. |
