Manufacture of magnet core used in inductive component such as choke for power factor correction, involves pressing mixture of amorphous coarse grain particle fraction with nanocrystalline fine grain powder particle fraction

摘要

A coarse grain powder fraction is produced from an amorphous soft magnetic strip, and a fine grain powder fraction is produced from nanocrystalline soft magnetic strip made of alloy capable of nanocrystallization. The produced fractions are mixed to obtain powder with multi-modal particle size distribution, and pressed to obtain magnet core. The particles of the coarse grain particle fraction have amorphous structure and the particles of the fine grain powder fraction have nanocrystalline structure. A coarse grain powder fraction is produced from an amorphous soft magnetic strip, and a fine grain powder fraction is produced from nanocrystalline soft magnetic strip made of alloy capable of nanocrystallization. The produced fractions are mixed to obtain powder with multi-modal particle size distribution, and pressed to obtain magnet core. The particles of the coarse grain particle fraction have amorphous structure and the particles of the fine grain powder fraction have nanocrystalline structure. The amorphous soft magnetic strip is alloy of composition: M aY' bZ c, where M is iron, nickel or cobalt, Y' is boron, carbon or phosphorus, Z is silicon, aluminum, germanium, a is 70-85 atomic%, b is 5-20 atomic% and c is 0-20 atomic%. Up to 10 atomic% of M may be replaced by titanium, vanadium, chromium, manganese, copper, zirconium, niobium, molybdenum, tantalum or tungsten and up to 10 atomic% of component (Y'+Z) may be replaced by indium, tin, antimony or lead. The alloy capable of nanocrystallization has composition of formula: (Fe 1 - a 1M a 1) 1 0 0 - x - y - z - a - b - cCu xSi yB zM' aM" bX c or (Fe 1 - a' - b'CoNi b) 1 0 0 - x' - y' - z'M1 x'B y'T z', where M is cobalt and/or nickel, M' is niobium, tungsten, tantalum, zirconium, hafnium, titanium or molybdenum, M" is vanadium, chromium, manganese, aluminum, element of platinum group, scandium, yttrium, rare earths, gold, zinc, tin or rhenium, X is carbon, germanium, phosphorus, gallium, antimony, indium, beryllium or arsenic, a1 is 0-0.5, x is 0.1-3, y is 0-30, z is 0-25, y+z is 0-35, a is 0.1-30, b,c are 0-10, M1 is niobium, tantalum, zirconium hafnium, titanium, vanadium or molybdenum, T is chromium, tungsten, ruthenium, rhodium, palladium, osmium, iridium, platinum, aluminum, silicon, germanium, carbon or phosphorus, a' is 0-0.29, b' is 0-0.43, x' is 4-10, y' is 3-15 and z' is 0-5. The alloy capable of nanocrystallization has composition preferably of formula: Fe 7 3 . 5Nb 3CuSi 1 5 . 5B 7, Fe 7 3 . 5Nb 3Cu 1Si 1 3 . 5B 9, Fe 8 6Cu 1Zr 7B 6, Fe 9 1Zr 7B 3 or Fe 8 4Nb 7B 9. The magnet core contains processing aids such as binders and/or lubricants.