Lämpösykliminen

Lämpösykliminen, also known as thermal cycling or thermal shock, refers to a process involving repeated exposure of a material or object to alternating high and low temperatures. This cyclic temperature variation can induce stresses within the material due to differential expansion and contraction. If these stresses exceed the material's strength, it can lead to fatigue, cracking, or other forms of degradation.

The rate of temperature change, the magnitude of the temperature extremes, and the duration of exposure at each temperature all influence the severity of thermal cycling. Materials with low thermal expansion coefficients and high fracture toughness generally exhibit better resistance to thermal cycling damage. Conversely, materials with significant differences in thermal expansion between their constituent parts or layers are more susceptible.

Thermal cycling is a critical consideration in various engineering applications. For instance, in the aerospace industry, components are subjected to extreme temperature fluctuations during atmospheric re-entry and operation at high altitudes. In the automotive sector, engine parts experience constant thermal cycling during operation. Electronics, particularly power semiconductors and circuit boards, also undergo thermal stress due to the heat generated during operation. Furthermore, materials used in high-temperature environments, such as in power plants or industrial furnaces, are routinely exposed to thermal cycling. Understanding and mitigating the effects of thermal cycling is essential for ensuring the long-term reliability and performance of many manufactured products.