Strong new alloys introduced by Navy

摘要

Nitinol is the name of a new class of nonmagnetic alloys developed by the Navy. It is expected to benefit a wide range of people, from the underwater demolition expert working on mines to the housewife working in her kitchen. Based on the intermetallic compound TnNi (a combination of titanium and nickel), it is corrosion resistant, and can be hardened to 62 Rockwell “C,” almost the hardness of tool steel. Tested up to 43 foot-pounds' impact strength, Nitinol differs from other alloys in that its toughness increases as temperatures decrease, yet it is suitable for use up to about 1,200 F. With a specific gravity of 6.45, it offers strength without adding weight, an advantage in aircraft, tools, etc. Its very high mechanical vibration capacity at room temperature decreases rapidly as temperature is increased.