Language
Country/Area
No result found
The shocking secret of heat: Why some glasses can withstand extreme temperatures?
In our daily lives, we often use glass products, but have you ever wondered why some glass can remain intact even in extreme temperatures? The reason behind this is the mystery of thermal shock and materials science. When the temperature changes rapidly, the uneven expansion of different parts of an object can create instantaneous mechanical loads that may cause the material to crack or fail. This article will take a closer look at this phenomenon and how to choose the right materials to resist thermal shock.
Basic principles of thermal shock
Thermal shock mainly comes from rapidly changing temperature. When different parts of an object are heated unevenly, strain rather than stress is generated, and this strain may exceed the tensile strength of the material. Experts at the website said: "When the strain exceeds the limit of the material, cracks will occur, eventually leading to structural failure." Therefore, understanding and preventing thermal shock is the key to ensuring material stability.
Strategies for Preventing Thermal Shock
According to existing research, there are several ways to prevent thermal shock:
- Change temperature gradually to reduce thermal gradients.
- Increase the thermal conductivity of the material.
- Reduce the thermal expansion coefficient of the material.
- Increase the strength of materials.
- Introducing compressive stress in the material, for example using strengthened glass.
- Reduce the Young's modulus of the material.
- Increase the toughness of the material by means of crack tip blunting or crack deflection.
Thermal shock resistance of glass
Baltic glass exhibits good thermal shock resistance due to its low coefficient of expansion and high strength.
This type of glass is not the only option; fused silica performs even better in this regard. In addition, some glass-ceramic materials are also good candidates. These materials (especially lithium aluminum silicate systems) can almost completely reduce their expansion coefficient by controlling the proportion of negative expansion materials.
Testing thermal shock resistance
One of the tools for measuring thermal shock is the impulse excitation technique, which can non-destructively measure the Young's modulus, shear modulus, Poisson's ratio and damping coefficient of the material. Measurements on the same specimen after each thermal shock cycle reveal the degree of deterioration in the physical properties. This testing helps predict how a material will perform in real-world applications.
Examples of Thermal Shock Failure
For example, if you put ice cubes into warm water, the outer layer will quickly heat up, causing excessive pressure on the internal structure, eventually causing the ice to crack.
This thermal shock effect is found in many materials. For example, in ancient gold mining, workers used hot wood to heat the rock surface and then rapidly cooled it with water to cause cracks.
Application scenarios
Technological advances have made thermal shock prevention measures more sophisticated. Thermal shock is one of the leading causes of head gasket failure in internal combustion engines. Selecting materials with good thermal shock resistance can significantly improve the service life and safety of these devices.
Conversely, choosing the right materials provides a line of defense for the use of materials in the production process of heat-resistant glass. This is crucial for common glassware, light bulbs, and even the facades of modern buildings.
Future Outlook
Opportunities always emerge in crises. In the future, we may see more innovative materials that target thermal shock resistance and are able to withstand larger temperature changes. As research continues to deepen, perhaps we will find more new ways to improve material performance, which will not only solve existing thermal shock problems, but also expand the scope of use of these materials.
In this rapidly changing world, is it possible to redefine our understanding of and response to thermal shock through the development of innovative materials?
