2014年8月26日星期二

the stretch of a spring titanium flat bar

Container of cold water in the aquarium , the stretch of a spring , when the spring into the hot water , springs and automatically folded up . Cold water in the spring to restore its original state , while in hot water , it will shrink , molybdenum sheet spring can be an unlimited number of stretching and shrinking , shrinking again opened. The memory consists of an intelligent made ​​of metal , the microstructure of which has two relatively stable at high temperatures of the alloy can be turned into any shape you want, the alloy at lower temperatures can be stretched , but if it is reheated , it will remember its original shape , and change back. This material is called memory metal (memory metal). It is mainly a nickel titanium material. For example , a helical superalloy, after high temperature annealing , titanium bar for sale which is in the shape of a spiral state. At room temperature , that is forced to use a lot of effort to straighten it , but as long as it is heated to a certain " abnormal temperature ," which seemed to root alloy remembered something, now restored to its original helical shape . How is this going ? Did alloy also has a kind of human memory ? Original not the case ! It's just the use of certain alloys law changes the crystal structure in the solid state with temperature only. For example , a nickel - titanium alloy titanium standards 40oC 40oC above and below the crystal structure is different, but the temperature change in the vertical 40oC , will be contracted or expanded metal , such that its shape is changed .

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