HIGH & LOW MAGNETIC PERMEABILITY MATERIALS FOR CUSTOM ULTRA HIGH VACUUM CHAMBERS
Posted on: April 17, 2017
Mu-Metal and 316LN-ESR Stainless Steel are specialty alloys which offer very different levels of magnetic permeability. Applied Vacuum offers expert custom vacuum chamber fabrication capabilities for these and other specialized materials. Mu-Metal is a nickel-iron alloy (77 % Ni, 15 % Fe, plus Cu and Mo) with extremely high magnetic permeability at low field strengths. Stray magnetic fields present a challenging issue for certain vacuum instruments, such as those used for electron spectroscopy. Mu-Metal is an ideal material to reduce the effects of magnetic fields inside these systems. Certain design criteria must be considered before embarking on the fabrication of Mu-Metal chambers. An alternative to constructing a complete custom vacuum chamber from Mu-Metal is to install liners or shields inside the chamber. The Mu-Metal shielding helps reduce the effects of magnetic fields within the vacuum system. 316LN-ESR Stainless Steel is produced using an electro-slag refinement process. Flanges manufactured from 316LN material have superior properties when compared to 304 and 316 SS versions, including very low magnetic permeability. AVT stocks 316LN-ESR bar and standard CF flanges to 6 inches. Larger sizes, other flange types, and custom components can be quickly quoted and manufactured in certified 316LN-ESR material.