Patent classifications
C04B2235/6022
FERRITE SINTERED MAGNET, FERRITE PARTICLES, BONDED MAGNET, AND ROTATING ELECTRICAL MACHINE
A ferrite sintered magnet has a ferrite phase having a magnetoplumbite-type crystal structure, and contains at least a metal element A, a metal element R, Fe, Co, Zn, and B. The element A is at least one kind of element selected from the group consisting of Sr, Ba, Ca, and Pb, and essentially includes Ca. The element R is at least one kind of element selected from the group consisting of Bi and rare-earth elements including Y, and essentially includes La. Atomic ratios of the metal elements satisfy the following expressions.
A.sub.1-rR.sub.rFe.sub.xCo.sub.yZn.sub.z (1)
0.40≤r≤0.70 (2)
8.20≤x≤9.34 (3)
0.05<y≤0.50 (4)
0<z≤0.20 (5)
The content of Si is 0 to 0.60% by mass in terms of SiO.sub.2, and the content of B is 0.01 to 0.70% by mass in terms of B.sub.2O.sub.3.
METHOD FOR MANUFACTURING A PART MADE OF A HARD MATERIAL WITH A POLYMER INSERT
A method is for manufacturing an ornamental part, for example a watch, jewellery or telephone part, in particular a watch crown. The part includes, at least partially, a hard material with a Vickers hardness exceeding 1,000 HV. The method includes the following main steps: producing a precursor from a mixture of at least one powder material with a binder, producing an insert made of a polymer material, the insert having, at least partially, a negative shape of that desired for at least one portion of the part, overmoulding the precursor onto the insert made of a polymer material by injection into a mould to form a green body, and sintering the green body to form a body of the future part from the hard material.
Binder for injection moulding compositions
A binder for an injection moulding composition including: from 40 to 55 volume percent of a polymeric base, from 35 to 45 volume percent of a mixture of waxes or a mixture of wax and palm oil, and at least 5 volume percent of at least one surfactant, wherein the polymeric base is formed of copolymers of ethylene and methacrylic or acrylic acid, copolymers of ethylene and propylene and/or maleic anhydride-grafted polypropylene, and polymers soluble in isopropyl alcohol, propyl alcohol and/or turpentine, and chosen from the group including a cellulose acetate butyrate, a polyvinyl butyral and a copolyamide, the respective quantities of the binder components being such that their sum is equal to 100 volume percent of the binder.
TOOL AND METHOD FOR MANUFACTURING A COMPOSITE-MATERIAL PART BY MEANS OF A LIQUID PROCESS
A tool for manufacturing a ceramic matrix composite part by injecting a slurry, the tool includes an injection chamber intended to receive at least one fibrous preform to be densified, wherein the injection chamber includes first injection ports which are formed in a first side of the injection chamber for injecting the slurry into the injection chamber, the first injection ports being distributed along the first side of the injection chamber; the injection chamber includes first drainage ports which are formed on the first side of the injection chamber for draining a liquid phase of the slurry from the injection chamber, the first drainage ports being distributed along the first side of the injection chamber; and the tool includes a first filtration element which is located on the first side of the injection chamber and which is located opposite the first drainage ports.
METHODS AND SYSTEMS FOR IN-PLANE SLURRY INFILTRATION OF COMPOSITE PREFORMS
Systems and methods for infiltrating a fibrous preform in the in-plane direction and forming composite components are provided. A system for infiltrating a fibrous preform may include a slurry reservoir defining a cavity configured to receive a fibrous preform. The cavity may be configured such that an internal surface of the slurry reservoir is spaced apart from an outer diameter of the fibrous preform. A slurry inlet may be formed in the slurry reservoir. The slurry inlet and the cavity may be configured such that a slurry input into the cavity infiltrates the fibrous preform in an in-plane direction.
Method for manufacturing a part made from CMC
Method for manufacturing a CMC, i.e. ceramic matrix composite material, part provided with at least one cutout, as well as to such a CMC part provided with at least one cutout, the method comprising the following steps: providing (E1) a fibrous reinforcement (10), forming (E2′) a cavity in a portion of the fibrous reinforcement (10), injecting (E3) a slip comprising at least a ceramic powder and a solvent, the slip being injected so as to impregnate the fibrous reinforcement (10′) and to fill the cavity of the fibrous reinforcement (10′), drying (E4) the obtained assembly, carrying out a densification (E6) by infiltration of a liquid densification material and solidification of said densification material, machining (E7) at least one cutout in the obtained blank (30) within the volume corresponding to the cavity of the fibrous reinforcement (10).
Systems and methods for infiltrating porous ceramic matrix composite (CMC) preforms
Systems and methods for infiltrating porous ceramic matrix composite (CMC) preforms to form CMC articles are disclosed. One method may include positioning the porous CMC preform in an opening of a die set for an infiltration system, and flowing a molten densifier over the porous CMC preform in a first flow direction to infiltrate a plurality of voids formed between each of a plurality of ply stacks of the CMC preform. The method may also include flowing the molten densifier over the porous CMC preform in a second flow direction, distinct from the first flow direction, to infiltrate the plurality of voids formed between each of the plurality of ply stacks of the CMC preform. The second flow direction may be substantially parallel to a predetermined, unidirectional material orientation of at least one ply stack of the plurality of ply stacks of the CMC preform.
Processes for preparing porous ceramics for acoustic transducers
A process for preparing a porous ceramic body includes forming a green body with a mixture of ceramic material powder, binder material, and pore-forming particles. The process further includes extracting the binder material, decomposing the pore-forming particles, and removing residual organic materials from the green body at respective, progressively higher pre-firing temperatures. After these three stages, the green body is sintered at a still-higher temperature to form the porous ceramic body. Embodiments facilitate manufacturing and can render most or all surface grinding unnecessary, allowing electrode deposition directly onto substantially non-porous surfaces of the porous ceramic body that are naturally formed during sintering. Advantageously, the green body may be formed into net shape by injection molding the mixture that includes the pore-forming particles, and embodiments can result in porous ceramic bodies that are much thicker than currently available, with better structural integrity.
Spherical Fused Silica Compositions for Injection Molded Ceramic Cores and Methods of Making Parts Using Such Compositions
A single crystal ceramic core composition has an inorganic portion and an organic portion. The inorganic portion makes up about 85% by weight of the total weight of the ceramic core composition, and the organic portion makes up about 15% by weight of the total weight of the ceramic core composition. The inorganic portion includes about 94 to 98% by weight spherical fused silica, and about 2 to 6% by weight zircon flour. The organic portion includes about 84 to 88% by weight binder, about 1 to 2% by weight dye, about 6 to 12% by weight surfactant, and about 1 to 5% by weight polymeric fiber.
Ferrite particles for bonded magnets, resin composition for bonded magnets, and molded product using the same
According to the present invention, there are provided ferrite particles for bonded magnets and a resin composition for bonded magnets which are capable of producing a bonded magnet molded product having a good tensile elongation and exhibiting excellent magnetic properties, as well as a bonded magnet molded product such as a rotor which is obtained by using the resin composition. The present invention relates to ferrite particles for bonded magnets having a bulk density of not less than 0.5 g/cm.sup.3 and less than 0.6 g/cm.sup.3 and a degree of compaction of not less than 65%, a resin composition for bonded magnets using the ferrite particles, and a molded product obtained by using the ferrite particles and the resin composition.