摘要:
Silicon nitride base sintered body consists of: 1 to 20 wt % (as oxides) of at least one of rare earth elements; 0.5 to 8 wt % of V (as V.sub.2 O.sub.5); 0.5 to 8 wt % (as oxides) of at least one of Nb, Ta, Cr, Mo and W; sum of the Va and VIa group elements according to the Periodic Table of the International Version (as oxides) being 1 to 10 wt %; and balance silicon nitride. It has high strength of 690-880 MPa (70-90 kgf/mm.sup.2) and high oxidation resistance both at 1350.degree. C. It is produced by 2 stage gas-pressure sintering in pressurized N.sub.2 atmosphere, primarily at 1700.degree.-1900.degree. C. at 1 MPa (10 atm) or less and secondarily at 1600.degree.-1900 C. at 10 MPa (100 atm) or above.
摘要:
A sintered silicon nitride product comprises from 72 to 98% by weight of silicon nitride, from 1 to 8% by weight of vanadium pentoxide, and from 1 to 20% by weight of one or more oxides of rare earth elements. The vanadium pentoxide and the oxide of rare earth elements accelerate the densification of the sintered product, and provide high strength at high temperature as well as excellent oxidation resistance to the sintered product.
摘要:
A silicon nitride sintered product comprises, in % by weight, 1 to 10% Mg, calculated as MgO, 1 to 10% Zr, calculated as ZrO.sub.2, 0.1 to 2.0% of at least one of Al, calculated as Al.sub.2 O.sub.3, Li, calculated as Li.sub.2 O, and Na, calculated as Na.sub.2 O, and the remainder being Si.sub.3 N.sub.4 and unavoidable impurities.
摘要:
A sintered body of silicon nitride having high strength, toughness and oxidation resistance consists essentially of, by weight percentages, 0.5 to 7.0% of a Mg component calculated as MgO, 0.5 to 7.0% of a Zr component calculated as ZrO.sub.2, 0.5 to 10.0% of a Ce component calculated as CeO.sub.2, and the balance being Si.sub.3 N.sub.4. The sum of Mg, Zr and Ce components calculated as oxides is 3 to 20% by weight. This product is suitable for engine parts or cutting tools.
摘要:
A sintered body of silicon nitride with high density, strength, toughness, and hardness, which can be used for a structural part of an engine, etc. The sintered body of the invention includes 80 to 94 wt % Si.sub.3 N.sub.4, 2 to 10 wt % Mg compound calculated in MgO equivlent, and 2 to 10 wt % Y compound calculated in Y.sub.2 O.sub.3 equivalent. The Si.sub.3 N.sub.4 contains 5 to 40% .alpha.-phase. The sintered body is manufactured in the following steps: (a) mixing powdery Si.sub.3 N.sub.4 with a Mg compound and a Y compound in the above proportions, and then molding the mixture in which the Si.sub.3 N.sub.4 powder contains 80% or more .alpha.-phase and its grains are 1 .mu.m or less in diameter on average; (b) performing primary sintering at 1,600.degree. C. or less in an atmospher of nitrogen or of an inert gas at 20 atm or less; and (c) performing secondary sintering at 1,400.degree. to 1,600.degree. C. in an atmosphere of nitrogen or of an inert gas at 300 atm or more.
摘要翻译:具有高密度,强度,韧性和硬度的氮化硅烧结体,其可用于发动机的结构部件等。本发明的烧结体包含80〜94重量%的Si 3 N 4,2〜10重量% 镁化合物按MgO计算,和2〜10重量%的Y化合物按Y2O3当量计算。 Si3N4含有5〜40%的α-相。 该烧结体按以下步骤制造:(a)以上述比例混合粉末状Si 3 N 4与Mg化合物和Y化合物,然后将其中Si 3 N 4粉末含有80%以上的α-相及其晶粒的混合物 平均直径1米以下; (b)在大气压的氮气或20atm以下的惰性气体中,在1600℃以下进行初次烧结; 和(c)在氮气气氛中或在大气压为300atm以上的惰性气体中,在1400℃〜1600℃进行二次烧结。
摘要:
An electrical device cabinet includes a cabinet body, a front panel, and a positioning mechanism. The cabinet body has an open front end. The front panel is formed by a resin molding, and is mounted to the front end of the cabinet body. The positioning mechanism includes a concave portion disposed at the cabinet body and a convex portion disposed at an inner face of the front panel. The positioning mechanism positions the front panel in a lateral direction with respect to the cabinet body by mating the concave portion and the convex portion. The convex portion is formed in a hollow shape and is covered by an outer face of the front panel from a front side of the front panel.
摘要:
An electrical device cabinet includes a cabinet body, a front panel, and a positioning mechanism. The cabinet body has an open front end. The front panel is formed by a resin molding, and is mounted to the front end of the cabinet body. The positioning mechanism includes a concave portion disposed at the cabinet body and a convex portion disposed at an inner face of the front panel. The positioning mechanism positions the front panel in a lateral direction with respect to the cabinet body by mating the concave portion and the convex portion. The convex portion is formed in a hollow shape and is covered by an outer face of the front panel from a front side of the front panel.
摘要:
In order to superimpose and store optical fiber ribbons in a corresponding one of spiral grooves provided in the outer circumferential surface of a spacer, an optical fiber ribbon stranding device includes: a device for advancing the spacer straight while rotating the spacer around the center axis of the spacer, the advancing device being constituted by, for example, a tension giving device and a take-up device; a device for feeding a plurality of optical fiber ribbons; a guide die for guiding the optical fiber ribbons into the corresponding one of the spiral grooves; and an alignment keeping guide disposed upstream of the guide die. A rectangular hole is provided to extend through the alignment keeping guide, and the optical fiber ribbons are passed through and superimposed by the hole. The optical fiber ribbons kept in a superimposed state by the alignment keeping guide is introduced and accommodated into the corresponding one of the grooves of the spacer through the guide die.
摘要:
The present invention is to improve a thermosetting composition which contains a polymer having a half-esterified acid anhydride group, thus enhancing water and weather resistance. The thermosetting resin composition comprises(I) a compound having an epoxy group and a hydroxy group, and(II) a copolymer prepared from a radically polymerizable monomer having an acid anhydride group and a copolymerizable monomer, of which said acid anhydride group is substantially completely half-esterified.
摘要:
The present invention provides a water borne metallic coating composition which stably disperses a metallic pigment and provides good metallic appearance independently of coating conditions. The water borne coating composition of the present invention comprises a specific film forming polymer (I), a specific fluorine containing compound (II), a metallic pigment (III), a crosslinking agent (IV), a compound (V) selected from the group consisting of a phosphorus containing titanate coupling agent and a phosphoric mono- or di-ester of a C.sub.11- C.sub.24 organic compound.