Thermal Shock - Examples of Thermal Shock Failure

Examples of Thermal Shock Failure

• Hard rocks containing ore veins such as quartzite were formerly broken down using fire-setting, which involved heating the rock face with a wood fire, then quenching with water to induce crack growth. It is described by Diodorus Siculus in Egyptian gold mines, Pliny the Elder and Georg Agricola.
• Ice cubes placed in a glass of warm water crack by thermal shock as the exterior surface increases in temperature much faster than the interior. As ice has a larger volume than the water that created it, the outer layer shrinks as it warms and begins to melt, whilst the interior remains largely unchanged. This rapid change in volume between different layers creates stresses in the ice that build until the force exceeds the strength of the ice, and a crack forms, sometimes with enough force to shoot ice shards out of the container.
• Incandescent bulbs that have been running for a while have a very hot surface. Splashing cold water on them can cause the glass to shatter due to thermal shock, and the bulb to implode.
• An antique cast iron cookstove is basically an iron box on legs, that has a cast iron top. One builds a wood or coal fire inside the box and cooks on the top outer surface of the box, like a griddle. If one builds too hot a fire, and then tries to cool the stove by pouring water on the top surface, it will crack and perhaps fail by thermal shock.
• The causes of three aircraft incidents in the 1990s (United Airlines Flight 585, USAir Flight 427 and Eastwind Airlines Flight 517). Thermal shock caused their power control unit in the tail to jam and cause rudder hardover, forcing the planes in the direction the rudder turns.
• It is widely hypothesized that following the casting of the Liberty Bell, it was allowed to cool too quickly which weakened the integrity of the bell and resulted in a large crack along the side of it the first time it was rung. Similarly, the strong gradient of temperature (due to the fire) is believed to cause the crash of the Tsar Bell.
• Thermal shock is a primary contributor to head gasket failure in internal combustion engines.