Invar 36 is a popular nickel-iron alloy known for its exceptionally low coefficient of thermal expansion. This makes it an ideal choice for applications where dimensional changes due to temperature fluctuations are undesirable. It has become a staple for the aerospace industry and is also used in many machine shops for tools that require high dimensional stability. It is highly resistant to corrosion in dry air at room temperature and can be used for cryogenic applications such as liquefied natural gas tankers.
In addition to iron (Fe) and nickel (Ni), the alloy also contains chromium (Cr) and cobalt (Co). All of these elements are essential for obtaining its unique machinability properties. The combination of these materials offers a number of advantages over other metals that can be machined but do not have the same level of machinability as Invar.
Achieving a high machining speed in Invar requires the use of high-speed machines and proper lubrication. This will help reduce the wear and tear on the tool. It will also allow for a more accurate cut and prevent the formation of chips that could result in damage to the workpiece and inaccurate measurements.
Invarās machinability properties are comparable to those of austenitic stainless steel. This allows for the production of near net shapes, which avoids expensive waste and cuts manufacturing costs. Additionally, it can be welded using conventional methods and brazed with silver or cadmium. It can be plated with nickel, chromium, or zinc.