Lämmönmurtuma

Lämmönmurtuma, also known as thermal shock or thermal stress fracture, refers to the cracking or fracturing of a material caused by rapid temperature changes. This phenomenon occurs when different parts of an object experience significantly different temperatures simultaneously, leading to uneven expansion or contraction. The resulting internal stresses can exceed the material's tensile strength, causing it to break.

The severity of lämmönmurtuma depends on several factors, including the material's thermal conductivity, its coefficient of thermal expansion, its inherent strength, and the magnitude and speed of the temperature change. Materials with low thermal conductivity and high thermal expansion coefficients are generally more susceptible to thermal shock. For instance, brittle materials like glass and ceramics are prone to lämmönmurtuma, especially when subjected to sudden heating or cooling.

Common examples of lämmönmurtuma include a hot glass shattering when cold water is poured into it, or engine components cracking due to repeated cycles of extreme heat and rapid cooling. In engineering, understanding and mitigating lämmönmurtuma is crucial for designing components that operate under fluctuating temperatures. This can involve selecting materials with better thermal shock resistance, modifying component geometry to reduce stress concentrations, or implementing controlled heating and cooling procedures. Preventive measures aim to minimize the temperature gradients within the material or to reduce the rate of temperature change.