Amorphous Co-based metal filaments and process for production of the same

Claim 2

A process for producing an amorphous Co-based metal filament having a circular cross-section which comprises jetting an alloy comprising 20 atomic percent or less of Si, and 7 to 35 atomic percent of B, the total of Si and B being 13 to 40 atomic percent and the remainder being composed substantially of Co, into a rotating member containing therein a cooling liquid through a spinning nozzle having a hole diameter satisfying the equation (III): D.sub.N ≦190-8|Si-11|-8|B+0.8Si-25|(III wherein D N is the hole diameter, in μm, of the spinning nozzle, Si is the atomic percent of Si in the alloy, and B is the atomic percent of B in the alloy, to thereby cool-solidify the spun filament, said rotating member being rotated at a circumferential speed equal to or greater than the rate of jetting the molten alloy through the spinning nozzle, and winding up the filament on the inner walls of the rotating member by the rotary centrifugal force thereof.

Claim 3

A process for producing an amorphous Co-based metal filament having a circular cross-section which comprises jetting an alloy comprising 20 atomic percent or less of Si, 7 to 35 atomic percent of B, and 30 atomic percent or less of at least one metal selected from the group consisting of Fe, Ni, Cr, Ta, Nb, V, Mo, Mn, W and Zr, the remainder being composed substantially of Co, provided that the total of Si and B is 13 to 40 atomic percent, Fe is 30 atomic percent or less, Ni is 20 atomic percent or less, Cr is 10 atomic percent or less, Ta is 10 atomic percent or less, Nb is 10 atomic percent or less, V is 10 atomic percent or less, Mn is 5 atomic percent or less, Mo is 5 atomic percent or less, W is 5 atomic percent or less, and Zr is 5 atomic percent or less, into a rotating member containing therein a cooling liquid through a spinning nozzle having a hole diameter satisfying the equation (IV): D.sub.N ≦K-8|Si-11|-8|B+0.8Si-25|(IV) wherein D N is the hole diameter, in μm, of a spinning nozzle, K is a constant as determined depending on the additional metal element with which a part of the Co metal element is replaced: when Fe, Ni, Mo, Mn, W or Zr is added, K=190, when Nb, Cr or V is added, K=300, and when Ta is added, K=400, provided that when two or more metal elements are added, the K value is the maximum value, Si is the atomic percent of Si in the alloy, and B is the atomic percent of B in the alloy, to thereby cool-solidify the spun filament, said rotating member being rotated at a circumferential speed equal to or greater than the rate of jetting the molten alloy through the spinning nozzle, and winding up the filament on the inner walls of the rotating member by the rotary centrifugal force thereof.

Claim 4

A process for producing an amorphous Co-based metal filament having a circular cross-section which comprises jetting an alloy comprising 20 atomic percent or less of Si, 7 to 35 atomic percent of B, and 30 atomic percent or less of at least one metal selected from the group consisting of Fe, Ni, Cr, Ta, Nb, V, Mo, Mn, W and Zr, the remainder being composed substantially of Co, provided that the total of Si and B is 13 to 40 atomic percent, Fe is 30 atomic percent or less, Ni is 20 atomic percent or less, Cr is 10 atomic percent or less, Ta is 10 atomic percent or less, Nb is 10 atomic percent or less, V is 10 atomic percent or less, Mn is 5 atomic percent or less, Mo is 5 atomic percent or less, W is 5 atomic percent or less, and Zr is 5 atomic percent or less, into a rotating member containing therein a cooling liquid through a spinning nozzle having a hole diameter satisfying the equation (IV): D.sub.N ≦K-8|Si-11|-8|B+0.8Si-25|(IV) wherein D N is the hole diameter, in μm, of a spinning nozzle, K is a constant as determined depending on the additional metal element with which a part of the Co metal element is replaced: when Fe, Ni, Mo, Mn, W or Zr is added, K=190, when Nb, Cr or V is added, K=300, and when Ta is added, K=400, provided that when two or more metal elements are added, the K value is the maximum value, Si is the atomic percent of Si in the alloy, and B is the atomic percent of B in the alloy, to thereby cool-solidify the spun filament, said rotating member being rotated at a circumferential speed equal to or greater than the rate of jetting the molten alloy through the spinning nozzle, and winding up the filament on the inner walls of the rotating member by the rotary centrifugal force thereof.