Thermal aging, spelled /ˈθɜːrməl eɪdʒɪŋ/, refers to the process of degradation or alterations of materials due to exposure to high temperatures. The word "thermal" is pronounced with a voiced "th" sound /ð/ and the emphasis on the first syllable, while "aging" is pronounced with a long "a" sound /eɪ/ and the emphasis on the second syllable. The consonant cluster "th" represents a phoneme that is not common in many languages, making it a challenging sound for some non-native speakers to pronounce.
Thermal aging refers to the process of degradation or changes that occur in materials, substances, or systems as a result of exposure to elevated temperatures over an extended period of time. The term is commonly used in the field of materials science and engineering, particularly in relation to polymers, metals, and electronic devices.
During thermal aging, the molecular structure and properties of the material can be altered due to various mechanisms such as chain scission, cross-linking, oxidation, and crystallization. These changes can lead to several detrimental effects, including reduced mechanical strength, increased brittleness, changes in conductivity or resistivity, and overall degradation of the material's performance.
The extent of thermal aging and its impact on a material is influenced by factors such as temperature, time of exposure, and the specific composition or structure of the material. Accelerated aging tests are often conducted to simulate the long-term effects of thermal aging within a shorter time frame, allowing researchers to assess the durability, reliability, and lifetime of a material or device under extreme thermal conditions.
Understanding and mitigating the effects of thermal aging is crucial in various industries, such as automotive, aerospace, electronics, and power generation. By studying the mechanisms and kinetics of thermal aging, scientists and engineers can develop strategies to enhance the thermal stability and extend the lifespan of materials and components exposed to high temperatures.
The word "thermal aging" is composed of two elements: "thermal" and "aging".
"Thermal" comes from the Greek word "thermos", meaning heat. It refers to anything related to heat or temperature.
"Aging" comes from the Old French word "aage" which means "age" or "time". It is derived from the Latin word "aetas", meaning "age" or "lifetime".
Therefore, the etymology of "thermal aging" indicates that it refers to the process of substances or materials deteriorating or changing over time due to exposure to heat or elevated temperatures.