Thermal Expansion

The coefficient of thermal expansion, also called the thermal expansion coefficient, tells you how much an object will expand when it’s heated up or cooled down. The higher the value of the thermal expansion coefficient, the more an object will change in size with temperature changes. 

Materials with larger coefficients of thermal expansion are more likely to shatter under pressure when they are subjected to sudden temperature changes. So if you’re working with materials that undergo extreme temperature changes, it’s important to know their thermal expansion coefficients and thus the limits of the materials so you can avoid cracking or breaking them.

A material’s coefficient of thermal expansion describes how much it expands as its temperature increases (or decreases). The coefficient of thermal expansion depends on the material and its temperature, so understanding it is important if you work with metals or plastics. Here are some reasons why you should know about the coefficient of thermal expansion in science and what it means for your work.

What is thermal expansion?

A coefficient of thermal expansion is a measure of how much something expands when exposed to heat. Many materials expand (and contract) when they’re heated and cooled, but others do not. Understanding how certain materials change size in response to heat can help you predict their behavior—and use it effectively. Let’s take a look at what the coefficient of thermal expansion means and why it’s important.

What is the coefficient of thermal expansion?

The coefficient of thermal expansion (CTE) is defined as the fractional change in volume per degree of temperature when it is measured over a range of temperatures. 

Most materials expand slightly with increasing temperature and contract with decreasing temperature; however, there are notable exceptions such as rubber, which contracts on cooling. CTE is dependent on both composition and structure.

How much does water expand when it freezes?

Water is unique in that it expands when it freezes, rather than contracts. This phenomenon is called thermal expansion, and it’s usually described with a value known as its coefficient of thermal expansion (CTE). When water freezes to ice, it absorbs heat energy to break its bonds and form a solid crystal lattice structure. In doing so, water will expand by about 9 percent.

What other materials show thermal expansion?

Because the coefficient of thermal expansion is a relative concept, one material’s coefficient will differ from that of another. Most materials do not show much thermal expansion, and often annealed materials will have lower coefficients than unannealed ones (glass, for example). However, there are many interesting examples where materials expand with heat or contract with cold.

Things to keep in mind when using materials with thermal expansion

Thermal expansion is a phenomenon that refers to how materials change in size when their temperature changes. 

Materials expand more with a large coefficient of thermal expansion, while they contract more with a small one. To make sure that thermal expansion won’t mess up your project, you should keep it in mind and do some measurements before using any material.

Coefficient Of Thermal Expansion For Steel

The coefficient of thermal expansion for steel varies widely depending on its carbon content. For example, low-carbon steel is far more flexible than high-carbon steel. The thermal expansion with respect to steel is an important factor to consider in engineering because it helps predict how well a design will perform in normal operating conditions. 

Temperature variations can cause the metal to warp or snap, so engineers often use their knowledge of coefficients of thermal expansion to predict what may happen and add additional materials if necessary. For steels it  occurs between 25 degrees Celsius and 100 degrees Celsius.

Conclusion

Thermal expansion is the phenomenon of materials expanding in size and volume when they are heated, or being compressed when they are cooled. Different materials expand to different extents depending on their coefficient of thermal expansion, and this coefficient varies depending on temperature and pressure as well as the type of material in question.