The metal spring of some hundredths of millimeter in diameter-what is so special in it? If you heat it up to the temperature of a human body, it will change its form right before your eyes. Such is an effect of an alloy with form memory properties. The journalist Yuri Drize describes perspectives of the use of such alloys in the article published in the Poisk newspaper.
The surprising material has been known in our country and abroad since 1960s. It was discovered in the course of deep studies of titanium alloys intended for aircraft, chemical and other industries. Transformation of metal occurs as a result of complex structural changes. To convince all those who could not believe in unprecedented properties of this material, a special experiment was organized and carried out in one of the pavilions of the Ail-Union Agricultural Exhibition (today known as the All-Russia Exhibition Center): a straight wire made of nickel and titanium alloy was heated there. It began bending, taking the shape of letters, and the astonished visitors finally could see the word "peace".
From the early 1980s, promising devices were introduced into medical practice: marvellous alloys enabled surgeons to avoid abdominal operations. After a thorough sterilization and preliminary cooling by means of liquid nitrogen, "metal structures" are introduced into a human body. First, they are compressed, transforming into tacks (thus it is easier to lead them through blood vessels) and finally, they reach a required organ. As they get heated, they "recall" the previous set form. Such "prostheses" have different purposes. For example, in case of esophagus cancer, food practically does not get into the body. To support a patient before surgery, the esophagus is expanded by means of a small tube of several centimeters in diameter. Metal structures can take any form-everything depends on the set medical tasks.
This unique technology was created by employees of the laboratory of phys ...
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