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:
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 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:
On a lithographic plate for printing, there is provided an identification mark which indicates for which color the lithographic plate is and in which printing press the lithographic plate is to be used. The identification mark of the lithographic plate is simultaneously recorded when image area rates of the lithographic plate are measured. When the measured lithographic plate is mounted in the printing press, the data of image area rates which have already been measured and recorded are read utilizing the result of reading the identification mark. The data are transmitted to the printing press and used for control of the ink supply amount of the printing press. In order to carry the lithographic plate keeping a flat state, there is provided a difference between air pressure acted upon one surface and another surface of the lithographic plate. A locating apparatus is also used so that the lithographic plate is set at a correct measuring position in order to measure image rates of the lithographic plate. An image rate can be thereby correctly measured for each portion of the lithographic plate.
摘要:
A spread spectrum communication system having a modulation unit for modulating and spreading an information signal by one or more of carrier signals and a spread code and transmitting it as a radio wave, and a demodulation unit for despreading and demodulating a received radio wave to pick up the information signal. The modulation unit includes a synthesizing and modulating unit for synthesizing a first primary modulated signal obtained by modulating a first carrier by the information signal and a second primary modulation signal obtained by modulating a second carrier, and a spectrum spreading unit for spreading the synthesized first and second primary modulation signals with a spread code to generate a spread spectrum signal containing first and second spread signal components. The demodulation unit includes a separation unit for separating a received spread spectrum signal into the first and second spread signals, a spread signal reproduction unit for reproducing the spread code on the separated first and second spread signal component, and a despreading unit for despreading the separated first spread signal component and reproduced spread code to reproduce the information signal.
摘要:
A horizontal rotary hook of a sewing machine includes an inner rotary hook made of synthetic resin and housing a bobbin, an outer rotary hook made of synthetic resin and housing the inner rotary hook and rotated in a predetermined direction, an adsorption plate made of a magnetic material and mounted on one of an outer surface of a bottom wall of the inner rotary hook and an inner surface of a bottom wall of the outer rotary hook, a magnet piece formed as a thin plate and mounted in the other of the outer surface of the bottom wall of the inner rotary hook and the inner surface of the bottom wall of the outer rotary hook, and a yoke member made of a magnetic material and housing the magnet piece integrally formed with a bottom wall contacting the magnet piece and a wall surrounding an outer circumferential side of the magnet piece. The yoke member is mounted on the other of the outer surface of the bottom wall of the inner rotary hook and the inner surface of the bottom wall of the outer rotary hook.
摘要:
A duplex data processing system includes two processors each provided with a bus connecting unit which disconnects the associated CPU bus from the cross connection bus in a separate mode or connects the CPU bus to the cross connection bus in a duplex mode. The system operates with a logically unified CPU bus through the connection of the internal CPU buses by the two bus connecting units in both processors.
摘要:
A triphenol type compound represented by the following formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 independently represent hydrogen, a halogen, a C.sub.1 -C.sub.5 alkyl group or a C.sub.1 -C.sub.5 alkoxy group.The triphenol type compound can be used, as a branching agent, for the production of a polycarbonate comprising (A) a carbonic acid component unit, (B) a divalent phenol component unit, and (C) a triphenol type compound component unit derived from the above-mentioned triphenol type compound. The triphenol type compound unit (C) is used in an amount of 0.01 to 10 mole %, based on the divalent phenol component unit (B) and the intrinsic viscosity [.eta.], determined at 25.degree. C. in methylene chloride, of the polycarbonate is 0.4 to 1.0 dl/g and the glass transition temperature (Tg), determined by a differential scanning type calorimeter is 150.degree. C. to 300.degree. C.
摘要:
A triphenol type compound represented by the following formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 independently represent hydrogen, a halogen, a C.sub.1 -C.sub.5 alkyl group or a C.sub.1 -C.sub.5 alkoxy group.The triphenol type compound can be used, as a branching agent for the production of a polycarbonate comprising (A) a carbonic acid component unit, (B) a divalent phenol component unit, and (C) a tripenol type compound component unit derived from the above-mentioned triphenol type compound. The triphenol type compound unit (C) is used in an amount of 0.01 to 10 mole %, based on the divalent phenol component unit (B) and the intrinsic viscosity [.eta.], determined at 25.degree. C. in methylene chloride, of the polycarbonate is 0.4 to 1.0 dl/g and the glass transition temperature (Tg), determined by a differential scanning type calorimeter is 150.degree. C. to 300.degree. C.