glennewdick
oh Terry9 once you bend any metal you get micro fractures so when you anneal the metal, heating and cooling under control you remove the micro fractures.
Mu metal is annealed by the manufacturer prior to shipping. That’s why bending annealed mu metal won’t produce micro fractures like unannealed mu metal. Think of it like cryogenic treatment, which is what it is. The molecular structure of the annealed alloy is much more homogeneous and less brittle and more ductile. Obviously for toroidal transformers no sharp bending is involved when wrapping the transformer. You just make a "hat box." Mu metal is quite soft and malleable so for square transformers use a cylinder shaped tool to form the alloy into gradual bends around the transformer, thus avoiding sharp bends. Problem solved!
Timely tip: TAKE CARE WHEN HANDLING MU METAL. Always use those special metal-cutting scissors with beveled edges that makes a blunt edge on the alloy. It’s ok to use gloves when handling mu metal. Otherwise you will suddenly realize your fingers are bleeding since mu metal edges are very very sharp.
oh Terry9 once you bend any metal you get micro fractures so when you anneal the metal, heating and cooling under control you remove the micro fractures.
Mu metal is annealed by the manufacturer prior to shipping. That’s why bending annealed mu metal won’t produce micro fractures like unannealed mu metal. Think of it like cryogenic treatment, which is what it is. The molecular structure of the annealed alloy is much more homogeneous and less brittle and more ductile. Obviously for toroidal transformers no sharp bending is involved when wrapping the transformer. You just make a "hat box." Mu metal is quite soft and malleable so for square transformers use a cylinder shaped tool to form the alloy into gradual bends around the transformer, thus avoiding sharp bends. Problem solved!
Timely tip: TAKE CARE WHEN HANDLING MU METAL. Always use those special metal-cutting scissors with beveled edges that makes a blunt edge on the alloy. It’s ok to use gloves when handling mu metal. Otherwise you will suddenly realize your fingers are bleeding since mu metal edges are very very sharp.