摘要:
A Si3N4 composite substrate which manifests no generation of cracking on the substrate even by mechanical shock or thermal shock, and is excellent in heat radiation property and heat-cycle-resistance property is obtained by using a Si3N4 substrate as a ceramic substrate. A Si3N4 substrate having a thermal conductivity of 90 W/m·K or more and a three-point flexural strength of 700 MPa or more is used, and the thickness tm of a metal layer connected on one major surface of the substrate and the thickness tc of the Si3N4 substrate are controlled so as to satisfy the relation formula: 2 tm≦tc≦20 tm. When metal layers are connected to both major surfaces of the Si3N4 substrate, the thickness tc and the total thickness ttm of the metal layers on both major surfaces are controlled so as to satisfy the relation formula: ttm≦tc≦10 ttm.
摘要翻译:通过使用Si 3 N 4基板作为陶瓷基板,可以获得表现出在机械冲击或热冲击下也不会在基板上产生裂纹的Si 3 N 4复合基板,并且具有优异的散热性和耐热循环性。 使用热导率为90W / mK以上,三点弯曲强度为700MPa以上的Si 3 N 4基板,连接在基板的一个主表面上的金属层的厚度tm和厚度tc 控制Si 3 N 4衬底以满足关系式:2tm <= tc <= 20tm。 当金属层连接到Si3N4基板的两个主表面时,控制两个主表面上的金属层的厚度tc和总厚度ttm,以满足关系式:ttm <= tc <= 10ttm。
摘要:
A feed pipe 26 for a sealing water is connected to a housing of the pump to communicate with an enclosed chamber which is defined between a position in which a helical seal line of screw rotors 17 isolates the enclosed chamber from a suction port 15 of the pump and another position in which the enclosed chamber begins to open to a discharge port 24. Alternatively, a feed pipe for the sealing water is connected to the suction port 15 of the vacuum pump, and the feed pipe 26 is provided with a valve V which opens when the suction pressure of the sealing water becomes lower than −380 mmHg.
摘要:
A discharge side housing 3 has a third cooling water chamber 19 communicating with a first cooling water chamber 7 of a main housing 1 through a cooling water passage 26. The third cooling water chamber 19 is connected to a cooling water outlet pipe 27 which is connected to an inlet port 28a of a three-way valve 28. The three-way valve 28 has a switching port 28b which can communicate with a pipe line 29 connected to the first cooling water chamber 7. The three-way valve 28 has an outlet 28c connected to a pipe line 30 which communicates with a second cooling water chamber 22 of a suction side housing 2. The second cooling water chamber 22 is connected to a cooling water discharge line 31 provided with a flow control valve 32 allowing a back pressure for a cooling water flowing thereinto.
摘要:
There are provided a process for forming a silicon nitride sintered body, encompassing a sialon sintered body, by making much of the superplasticity of the sintered body intact as a simple material without formation thereof into a composite material, and a formed sintered body produced by the foregoing process. A silicon nitride sintered body (encompassing a sialon sintered body) having a relative density of at least 95% and a linear density of 120 to 250 in terms of the number of grains per 50 .mu.m in length in a two-dimensional cross section of the sintered body is formed through plastic deformation thereof at a strain rate of at most 10.sup.-1 /sec under a tensile or compressive pressure at a temperature of 1,300 to 1,700.degree. C. The formed sintered body has a degree of orientation of 5 to 80% as examined according to a method specified by Saltykov, a linear density of 80 to 200, and excellent mechanical properties especially at ordinary temperatures.
摘要:
The strength of a composite sintered body including yttrium oxide is improved. A composite ceramics sintered body includes a matrix of yttrium oxide and silicon carbide particles dispersed within the matrix. A compound oxide phase including yttrium and silicon is present at the surface of the sintered body. A sintered body is obtained by compression-molding mixed powder including yttrium oxide powder and silicon carbide powder in an inert gas atmosphere of at least 1550.degree. C. The sintered body is subjected to a heat treatment for at least 0.5 hour and not more than 12 hours in an atmosphere including oxygen gas in the range of at least 900.degree. C. and less than 1200.degree. C.
摘要:
There is provided a transparent polycrystalline spinel substrate characterized in having a transmittance of 0.005% or less in a crossed Nicol system at a thickness of 1 mm and a wavelength of 450 nm, which does not generate image blurring or light-dark change when used in optical products. There is also provided a method for producing the transparent polycrystalline spinel substrate comprising a step for preparing a spinel powder, a step for molding the spinel powder and producing a spinel formed body, a step for sintering the spinel formed body and producing a spinel sintered body, and a step for subjecting the spinel sintered body to hot isostatic pressing (HIP) and producing a spinel polycrystalline body. There is further provided a liquid crystal projector and a receiver for rear-projection television having the aforementioned transparent polycrystalline spinel substrate.
摘要:
Highly wear-resistant, low-friction ceramic composites suited for machining-tool, sliding-component, and mold-die materials are made available. The ceramic composites characterized are constituted from a phase having carbon of 3 μm or less, preferably 30 nm or less, average crystal-grain size as the principal component, and a ceramic phase (with the proviso that carbon is excluded). The ceramic phase is at least one selected from the group made up of nitrides, carbides, oxides, composite nitrides, composite carbides, composite oxides, carbonitrides, oxynitrides, oxycarbonitrides, and oxycarbides of Al, Si, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W. The ceramic composites are produced by sintering the source-material powders at a sintering temperature of 800 to 1500° C. and a sintering pressure of 200 MPa or greater.
摘要:
There is provided a method of manufacturing a molded article formed with a thermosetting resin and an injection molding apparatus so that occurrence of blurs and containing of bubbles at the time of molding can be prevented. Provided is a method of manufacturing a molded article formed with a thermosetting resin by using a mold including: a cavity for molding a product part; a gate which commutes with the cavity to guide a liquid thermosetting resin into the cavity, thereby forming a gate part; a runner which commutes with the gate part to guide the liquid resin into the gate part, thereby forming a runner part; and an overflow catcher which commutes with the cavity to receive the liquid resin overflown from the cavity, thereby forming an overflow part, wherein the method includes: an injecting process of injecting the liquid resin from the runner through the gate to the cavity, until the overflow catcher is filled from the cavity; a hardening process of heating the liquid resin in the mold, thereby hardening the liquid resin; a demolding process of demolding a resin molded article having the runner part, the gate part, the product part, and the overflow part from the mold; and a cutting process of detaching the gate part and the overflow part from the product part of the demolded resin molded article.
摘要:
The present invention provides a silicon nitride-based sintered body having excellent mechanical properties from room temperature to a medium-low temperature range, a low friction coefficient and excellent wear resistance; a raw material powder for the sintered body; a method of producing the raw material powder; and a method of producing the sintered body. The sintered body of the present invention comprises silicon nitride, titanium compounds and boron nitride, or else silicon nitride, a titanium-based nitride and/or carbide, silicon carbide and graphite and/or carbon; and it has a mean particle diameter of 100 nm or less, and a friction coefficient under lubricant-free conditions of 0.3 or less, or else 0.2 or less. The silicon nitride-based composite powder, which is the raw material of the sintered body comprises primary particles of each of silicon nitride and titanium compounds, containing boron or carbon, each having a mean particle diameter of 20 nm or less, or 30 nm or less, and a phase containing an amorphous phase that surrounds the surfaces of the primary particles. Moreover, the method of producing the sintered body comprises pulverizing and mixing a silicon nitride powder, a sintering aid powder, a metallic titanium powder and a boron nitride powder, or else a silicon nitride powder, a sintering aid powder, a metallic titanium powder and a graphite and/or carbon powder, until the mean particle diameters become 20 nm or less, or else 30 nm or less, thus forming secondary
摘要:
A conductive silicon nitride composite sintered body having an average grain size of 200 nm or less and whose relative roughness (Ra) after electric discharge machining is 0.6 μm or less can be obtained by grinding/mixing a silicon nitride powder and a metal powder together until the average particle size of the silicon nitride powder becomes 30 to 60 nm, and subsequently by molding and sintering. With the contexture that is characteristic of the present invention, it is possible to obtain a conductive silicon nitride composite sintered body having electric conductive particles of 5 to 60 volume percent that is capable of electric discharge machining.