- MACOR
MACOR® is a machineable
glass-ceramic developed and sold byCorning Incorporated . It is a white material that looks somewhat likeporcelain . MACOR has excellent thermal characteristics, acting as efficient insulation, and stable up to temperatures of 1000 °C, with very littlethermal expansion or outgassing. It can be machined into any desired shape using standardmetalworking bits and tools. This combination of machineability and good thermal properties have made it the material of choice in manyengineering contexts.Composition
MACOR is made up of fluorphlogopite
mica in aborosilicate glass matrix. Its composition is roughly:
*46%silicon (SiO2)
*17%magnesium (MgO)
*16%aluminium (Al2O3)
*10%potassium (K2O)
*7%boron (B2O3)
*4%fluorine (F)Properties
MACOR has a
density of 2.52 g/cm3, and athermal conductivity of 1.46 W/(m·K). Its low-temperature (25 to 300 °C)thermal expansion is 93×10-7 m/(m·K).MACOR is a very good insulator with excellent tolerance. Even with temperature changes, its low thermal expansion ensures that its shape changes very little.
afety
There are no major
safety concerns ortoxic effects associated with MACOR. Its excellent temperature stability makes it safe in most situations. Thedust created when machining it can be anirritant and inhalation should of course be avoided.MACOR can burn/explode in oxygen under extremely high temperatures, or very rapid temperature changes. The flame is usually quite bright (risk of blinding), but usually extinguishes rapidly.
Applications
MACOR is used in a wide variety of industries, including
aerospace ,nuclear engineering ,medicine , and fundamental research. It is often used in high-temperature and/or high-vacuum environments, where dimensional stability and low outgassing are critical. [ [http://www.corning.com/docs/specialtymaterials/pisheets/Macor.pdf MACOR Brochure for pdf ] ]References
Wikimedia Foundation. 2010.