Sumitomo Special Metals Co., Ltd.

Neomax Co., Ltd.

Hitachi Metals, Ltd.

Santoku Corporation

Meomax Co., Ltd.

Sumitomo Special Co., Ltd.

Satoshi Hirosawa

Hirokazu Kanekiyo

Toshio Miyoshi

Takeshi Nishiuchi

Yasutaka Shigemoto

Noriyuki Nozawa

Tomohito Maki

Ryosuke Kogure

Ryo Murakami

Hiroyuki Tomizawa

Katsunori Bekki

Yusuke Shioya

Masato Sagawa

Setsuo Fujimura

Hitoshi Yamamoto

Ken Makita

Tsutomu Mashimo

Hirokazu Kitayama

Takashi Ikegami

Atsushi Hanaki

Shuji Mino

Hirofumi Wada

An R&#x2014;Fe&#x2014;B based porous magnet according to the present invention has an aggregate structure of NdFeB type crystalline phases with an average grain size of 0.1 &#x3bc;m to 1 &#x3bc;m. At least a portion of the magnet is porous and has micropores with a major axis of 1 &#x3bc;m to 20 &#x3bc;m.

R&#x2014;Fe&#x2014;B porous magnet and method for producing the same

R-Fe-B porous magnet and method for producing the same

An R&#x2014;Fe&#x2014;B based rare-earth alloy powder with a mean particle size of less than about 20 &#x3bc;m is provided and compacted to make a powder compact. Next, the powder compact is subjected to a heat treatment at a temperature of about 550&#xb0; C. to less than about 1,000&#xb0; C. within hydrogen gas, thereby producing hydrogenation and disproportionation reactions (HD processes). Then, the powder compact is subjected to another heat treatment at a temperature of about 550&#xb0; C. to less than about 1,000&#xb0; C. within either a vacuum or an inert atmosphere, thereby producing desorption and recombination reactions and obtaining a porous material including fine crystal grains, of which the density is about 60% to about 90% of their true density and which have an average crystal grain size of about 0.01 &#x3bc;m to about 2 &#x3bc;m (DR processes). Thereafter, the porous material is subjected to yet another heat treatment at a temperature of about 750&#xb0; C. to less than about 1,000&#xb0; C. within either the vacuum or the inert atmosphere, thereby further increasing its density to about 93% or more of their true density and making an R&#x2014;Fe&#x2014;B based microcrystalline high-density magnet.

R-Fe-B microcrystalline high-density magnet and process for production thereof

A nanocomposite magnet according to the present invention has a composition represented by the general formula: RQM(FeT), where R is at least one rare-earth element, Q is at least one element selected from the group consisting of B and C, M is at least one metal element that is selected from the group consisting of Al, Si, Ti, V, Cr, Mn, Cu, Zn, Ga, Zr, Nb, Mo, Ag, Hf, Ta, W, Pt, Au and Pb and that always includes Ti, and T is at least one element selected from the group consisting of Co and Ni. The mole fractions x, y, z and m satisfy the inequalities of 6 at %&#x2266;x&#x3c;10 at %, 10 at %&#x2266;y&#x2266;17 at %, 0.5 at %&#x2266;z&#x2266;6 at % and 0&#x2266;m&#x2266;0.5, respectively. The nanocomposite magnet includes a hard magnetic phase and a soft magnetic phase that are magnetically coupled together. The hard magnetic phase is made of an RFeB-type compound, and the soft magnetic phase includes an &#x3b1;-Fe phase and a crystalline phase with a Curie temperature of 610&#xb0; C. to 700&#xb0; C. (&#x3c9; phase) as its main phases.

Nano-composite magnet, quenched alloy for nano-composite magnet, and method for producing them and method for distinguishing them

A method of making a magnetic alloy material includes the steps of: preparing a melt of an alloy material having a predetermined composition; rapidly cooling and solidifying the melt to obtain a rapidly solidified alloy represented by: FeREATMwhere RE is at least one rare-earth element selected from La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er and Tm and including at least about 90 at % of La; A is at least one element selected from Al, Si, Ga, Ge and Sn; TM is at least one transition metal element selected from Sc, Ti, V, Cr, Mn, Co, Ni, Cu and Zn; and 5 at %&#x2266;a&#x2266;10 at %, 4.7 at %&#x2266;b&#x2266;18 at % and 0 at %&#x2266;c&#x2266;9 at %; and producing a compound phase having an NaZn-type crystal structure in at least about 70 vol % of the rapidly solidified alloy.

Magnetic alloy material and method of making the magnetic alloy material

A magnetic alloy material according to the present invention has a composition represented by FeREACo, where RE is a rare-earth element always including La, A is either Si or Al, 6 at %&#x2266;a&#x2266;11 at %, 8 at %&#x2266;b&#x2266;18 at %, and 0 at %&#x2266;c&#x2266;9 at %, and has either a two phase structure consisting essentially of an &#x3b1;-Fe phase and an (RE, Fe, A) phase including 30 at % to 90 at % of RE or a three phase structure consisting essentially of the &#x3b1;-Fe phase, the (RE, Fe, A) phase including 30 at % to 90 at % of RE and an RE(Fe, A)compound phase with an NaZn-type crystal structure. The respective phases have an average minor-axis size of 40 nm to 2 &#x3bc;m.

To make a raw alloy, consisting mostly of amorphous structure, highly productively and at a reduced cost for a nanocomposite magnet, a molten alloy represented by FeRQM(where R is at least one element selected from Pr, Nd, Dy and Tb; Q is B and/or C; M is at least one element selected from Co, Al, Si, Ti, V, Cr, Mn, Ni, Cu, Ga, Zr, Nb, Mo, Ag, Pt, Au and Pb; and 1 at %&#x2266;x&#x3c;6 at %, 15 at %&#x2266;y&#x2266;30 at % and 0 at %&#x2266;z&#x2266;7 at %) is prepared. This molten alloy is rapidly cooled by a strip casting process in which the alloy is fed onto a chill roller, rotating at a peripheral velocity of 3 m/s to less than 20 m/s, at a feeding rate per unit contact width of 0.2 kg/min/cm to 5.2 kg/min/cm. In this manner, an alloy including at least 60 volume percent of amorphous phase can be obtained.

Process for producing, through strip casting, raw alloy for nanocomposite type permanent magnet

A rare-earth alloy powder is obtained by rapidly cooling a melt of an alloy by an atomization process. The alloy has a composition represented by (FeT)QRTiM, where T is at least one of Co and Ni, Q is at least one of B and C, R is at least one of the rare-earth metal elements and yttrium, and M is at least one of Nb, Zr, Mo, Ta and Hf. The mole fractions x, y, z, m and n satisfy 10 at %&#x3c;x&#x2266;25 at %, 6 at %&#x2266;y&#x3c;10 at %, 0.1 at %&#x2266;z&#x2266;12 at %, 0&#x2266;m&#x2266;0.5, and 0 at %&#x2266;n&#x2266;10 at %, respectively. By adding Ti to the alloy, the nucleation and growth of &#x3b1;-Fe during the rapid quenching process can be minimized.

Method for producing nanocomposite magnet using atomizing method

An iron-based rare earth alloy magnet has a composition represented by the general formula: (FeT)QRM, where T is at least one element selected from the group consisting of Co and Ni; Q is at least one element selected from the group consisting of B and C; R is at least one rare earth element substantially excluding La and Ce; and M is at least one metal element selected from the group consisting of Ti, Zr and Hf and always includes Ti. In this formula, the mole fractions x, y, z and m meet the inequalities of: 10 at %&#x3c;x&#x2266;20 at %; 6 at %&#x2266;y&#x3c;10 at %; 0.1 at %&#x2266;z&#x2266;12 at %; and 0&#x2266;m&#x2266;0.5, respectively.

Permanent magnet including multiple ferromagnetic phases and method for producing the magnet

A nanocomposite magnet has a composition represented by (FeT)QRTiM, where T is at least one of Co and Ni, Q is at least one of B and C, R is at least one rare earth element that always includes at least one of Nd and Pr and optionally includes Dy and/or Tb, and M is at least one element selected from the group consisting of Al, Si, V, Cr, Mn, Cu, Zn, Ga, Zr, Nb, Mo, Ag, Hf, Ta, W, Pt, Au and Pb. The mole fractions x, y, z, m and n satisfy 10 at %&#x3c;x&#x2266;20 at %, 6 at %&#x2266;y&#x3c;10 at %, 0.5 at %&#x2266;z&#x2266;12 at %, 0&#x2266;m&#x2266;0.5 and 0 at %&#x2266;n&#x2266;10 at %, respectively. The nanocomposite magnet has an oxygen content of at most about 1,500 ppm by mass.

Nanocomposite magnet

A compound for a rare-earth bonded magnet includes a rare-earth alloy powder and a binder. The rare-earth alloy powder includes at least about 2 mass % of Ti-containing nanocomposite magnet powder particles with a composition represented by (FeT)QRM, where T is Co and/or Ni; Q is B with or without C; R is at least one rare-earth element substantially excluding La and Ce; M is at least one metal element selected from Ti, Zr and Hf and always includes Ti; and 10&#x3c;x&#x2266;20 at %; 6&#x2266;y&#x3c;10 at %; 0.1&#x2266;z&#x2266;12 at %; and 0&#x2266;m&#x2266;0.5. The particles include at least two ferromagnetic crystalline phases, in which hard magnetic phases have an average crystal grain size of about 10 nm to about 200 nm, soft magnetic phases have an average crystal grain size of about 1 nm to about 100 nm; and the average crystal grain size of the soft magnetic phases is smaller than that of the hard magnetic phases.

Compound for rare-earth bonded magnet and bonded magnet using the compound

An iron-based rare earth alloy nanocomposite magnet has a composition represented by (FeT)QRTi, where T is Co and/or Ni, Q is B and/or C and R is rare earth element(s) including substantially no La or Ce. x, y, z and m satisfy 10 at %&#x3c;x&#x2266;17 at %, 7 at %&#x2266;y&#x3c;10 at %, 0.5 at %&#x2266;z&#x2266;6 at % and 0&#x2266;m&#x2266;0.5, respectively. The magnet includes crystal grains of an RTQ type compound having an average grain size of 20 nm to 200 nm and a ferromagnetic iron-based boride that exists in a grain boundary between the crystal grains of the RTQ type compound. The boride is dispersed in, or present in the form of a film over, the grain boundary to cover at least partially the surface of the crystal grains of the RTQ type compound.

Iron-based rare earth alloy nanocomposite magnet and method for producing the same

A method of making a material alloy for an iron-based rare earth magnet includes the step of forming a melt of an alloy with a composition of (FeT)(BC)RTiM. T is Co and/or Ni; R is at least one element selected from Y (yttrium) and the rare earth elements; and M is at least one element selected from Al, Si, V, Cr, Mn, Ni, Cu, Zn, Ga, Zr, Nb, Mo, Ag, Hf, Ta, W, Pt, Au and Pb, wherein the following inequalities are satisfied: 10&#x3c;x&#x2266;25 at %, *6&#x2266;y&#x3c;10 at %, 0.5&#x2266;z&#x2266;12 at %, 0&#x2266;m&#x2266;0.5, 0&#x2266;n&#x2266;10 at % and 0&#x2266;p&#x2266;0.25. Next, the melt is fed onto a shoot with a guide surface tilted at about 1 degree to about 80 degrees with respect to a horizontal plane, thereby moving the melt onto a melt/roller contact region. The melt is then rapidly cooled using a chill roller to make a rapidly solidified alloy including an RFeB phase.

Growing community of inventors

Otsu, Japan

Satoshi Hirosawa