Ngk Insulators, Inc.

Isao Oda

Nobuo Tsuno

Masayuki Kaneno

Tadaaki Matsuhisa

Takao Soma

Yoshihiko Ishida

Noboru Yamamoto

Tomonori Takahashi

Minoru Matsui

Kiminari Kato

Issei Hayakawa

Koichiro Maekawa

Yoshizumi Nakasuji

Takashi Ando

A metallic slide member is disclosed which is advantageously used in combination with an opponent ceramic slide member. The metallic slide member is capable of forming a metal coat lubricating layer on a sliding surface of the ceramic slid member through a metal at a sliding surface of the metallic slide member being transferred onto the ceramic slide member when the metallic slide member slide relative to the ceramic member. Thereby, excellent wear resistance of the metallic slide member can be maintained with respect to the ceramic slide member.

Metallic slide members to be used with ceramic slide members and sliding

Composite bodies comprise a metallic member and a ceramic member integrally joined together by joining a projection of the ceramic member to a recess of the metallic member. Their joining strength is improved by substantially limiting brazing metal to an interface between the outer peripheral surface of the projection of the ceramic member and the innner peripheral surface of the recess of the metallic member. The joining strength is also improved by forming a groove around the outer periphery of the metallic member at the joined end. The joining strength is also improved by providing a space or an intermediate member between a tip end surface of the projection and a bottom surface of the recess and attaining the relation: ##EQU1## in which G, L.sub.1, .alpha., .alpha.', T.sub.S and T.sub.R are the thickness of the space or the intermediate member, a distance from the bottom surface of the recess of the metallic member to the joining end, a coefficient of thermal expansion of the metallic member, a coefficient of thermal expansion of the ceramic member, a solidifying temperature of the brazing metal, and room temperature, respectively. The joining strength is also improved by radially enlarging the recess near the opening and thinning the brazing metal toward the opening of the recess.

Metal-ceramic joined composite bodies and joining process therefor

Ceramic-metal composite bodies are disclosed, which are each formed by joining a projection on a ceramic member to a recess or a through hole formed in a metallic member together. A groove portion is provided substantially all around the outer periphery of the metallic member such that a fitting end of the metallic member is located in a position corresponding to the groove portion. A difference between a diameter of a bottom of the groove portion and an outer diameter of the projection of the ceramic member is 0.05 to 0.8 times as large as a difference between an outer diameter of the metallic member and the outer diameter of the projection of the ceramic member.

Ceramic-metal composite bodies

A metal-ceramic composite body is disclosed, which comprises a metallic member having a depression or through-hole therein, and a ceramic member having a protrusion capable of inserting into the depression or through-hole. Both the members are joined to each other through interference fitting below such a temperature that the structure of the metallic material begins to change into austenite phase or a temperature between the above temperature and a service temperature.

Metal-ceramic composite bodies

A metal-ceramic composite body is produced by fitting a protruding portion of a ceramic member into a concave portion of an intermediate member and joining the intermediate member to a metallic member. In this case, a difference between the inner diameter in the concave portion of the intermediate member and the outer diameter in the protruding portion of the ceramic member is not less than 0.2% of the outer diameter in the protruding portion when the protruding portion is pulled out from the concave portion.

Slide assemblies, which each include a metallic member and a ceramic member to slide with the metallic member. The metallic member has a sliding surface coated with a mixture consisting essentially of a solid lubricant and a binder. The mixture of the solid lubricant and the binder is a combination selected from the group consisting of LiF+MoO.sub.3, PbO+Cu, MoS.sub.2 +Cu, LiF+Ni--Cr--Mo--Si, and LiF+Co--Mo--Cr--Si. Silicon nitride, sialon, mullite, partially stabilized zirconia, or silicon carbide is preferably used as the ceramic member. The slide assemblies exhibit excellent high frictional resistance and wearing resistance even in dry condition at high temperatures.

Slide assemblies

A ceramic rotor is produced by sequentially forming a ceramic rotary body portion, measuring the dynamic unbalance of the ceramic rotary body portion, grinding the ceramic rotary body portion to adjust the dynamic unbalance and then integrally coupling a rotary shaft to the ceramic rotary body portion.

Method of producing a ceramic rotor

In a metal-ceramic combination wherein a monobloc ceramic member comprising a base, a protrusion integrally formed on the base and an easement portion on and around the root of the protrusion, is combined with a metallic member, an improved combination having an excellent strength in total is obtained by fitting the protrusion tightly into a recession or conduit of the metallic member, leaving clearance of 0.5 mm or more between the easement portion and a defined edge of joint interface of the said two members. The combination of the invention is particularly useful for engine parts to be subjected to high temperatures and repeated stresses such as a turbocharger rotor, piston, tappet, rocker arm, exhaust valve, cam and the like.

Metal-ceramic combination

A method of producing turbine rotor having a including vane wheel made of ceramics, a ceramic shaft formed integrally with the turbine wheel, and a metallic shaft bonded to the ceramic shaft. The hardness of a part of or the whole part of a compressor wheel-fitting shaft portion of the metallic shaft is made smaller than that of a portion of metallic shaft apart from the compressor wheel-fitting shaft, said portion being located on the turbine vane wheel side. Thereby, slackening between the compressor wheel and the fitting shaft is avoided.

Method of producing a turbine rotor

High strength porcelain having an unglazed bending strength of greater than 1,400 kg/cm.sup.2 and consisting essentially of 22-85% by weight of SiO.sub.2, 10-73% by weight of Al.sub.2 O.sub.3, and 1.5-6.5% by weight of K.sub.2 O and/or Na.sub.2 O. The porcelain has a total degree of crystallinity of more than 40% by weight, and a crystalline grain size of not greater than 20 .mu.m, and it is free from defects of larger than 40 .mu.m. The porcelain is produced by pulverizing a starting material mixture of quartz-feldspar-alumina system so that 85-95% by weight of particles thereof have a grain size of not greater than 10 .mu.m, calcining the mixture, adding clay-mineral material therein, pulverizing so that the clay-mineral-added mixture contains less than 85% by weight of particles with a grain size of not greater than 10 .mu.m, forming, drying, and firing at 1,100.degree.-1,400.degree. C.

Method for producing a high strength feldspathic porcelain

A silicon nitride sintered body having an improved oxidation resistance or wear resistance has in its surface a coating of silicon carbide. Particularly, the coating of silicon carbide is formed by CVD process.

Silicon nitride sintered bodies

Ceramic rotors for pressure wave superchargers are disclosed, which have a honeycomb structure, wherein a material constituting partition walls of the honeycomb structure has an apparent density of 4.0 g/cm.sup.3 or less, an open porosity of 3.0% or less, a coefficient of thermal expansion in a temperature range from room temperature to 800.degree. C. being 5.5.times.10.sup.-6 /.degree.C. or less, and a four point bending strength of 30 kg/mm.sup.2 or more. A process for producing such ceramic rotors for pressure wave superchargers is also disclosed. The process includes the steps of preparing a ceramic body in which an average particle diameter of a ceramic raw material is controlled to 1 to 10 .mu.m, extruding honeycomb structural bodies by press feeding the ceramic body through body feed holes and extruding channels having a width corresponding to a thickness of partition walls of the honeycomb structure in an extruding die, drying, firing and grinding the thus extruded bodies.

Ceramic rotors for pressure wave superchargers and production thereof

Metallizing pastes are disclosed, which contain, as inorganic materials, 15 to 50% by weight of a component to form a glass phase and 50 to 85% by weight of a metallic molybdenum powder. The glass phase essentially consists of 5 to 25% by weight of Al.sub.2 O.sub.3, 35 to 55% by weight of SiO.sub.2 and 30 to 55% by weight of MnO. A process for metallizing ceramic members is also disclosed. The metallizing paste is applied to surfaces of the ceramic member and the dried. The ceramic member with the dried metallizing paste is then fired in a temperature range from 1,200.degree. to 1,400.degree. C. for 0.5 to 10 hours in a mixed gas of hydrogen gas and nitrogen gas in which a ratio in partial pressure between steam and hydrogen, (P.sub.H.sbsb.2.sub.O /P.sub.H.sbsb.2), is adjusted in a range from 10.sup.-6 to 10.sup.0.

Metallizing paste and a process for metallizing ceramic articles by

Metal-ceramic composite bodies are disclosed which each comprise a metallic member and a ceramic member. The metallic member is integrally connected to the ceramic member by fitting the ceramic member itself or a projection formed on the ceramic member into a recess or a through hole formed in the metallic member. The hardness of a metallic portion of including at least a fitted portion between the metallic member and the ceramic member is not less than HRC 38. The roughness of the inner surface of the faces of the through hole of the metallic member at the fitted portion is not more than 8 .mu.m at the maximum height (R.sub.max) or not more than 0.5 .mu.m at the center line average roughness (R.sub.a). A process for manufacturing the same is also disclosed.

Metal-ceramic composite bodies and a method for manufacturing the same

A ceramic-metal composite body comprises a ceramic member with a projection formed thereon and a metallic member with a depression or through hole formed therein. The ceramic member and the metallic member are bonded together by fitting the projection of the ceramic member into the depression or through hole of the metallic member. The difference between the outer diameter of the projection of the ceramic member and the inner diameter of the depression or through hole of the metallic member when the projection of the ceramic member is extracted from the depression or through hole of the metallic member is not less than 0.2% of the outer diameter of the projection of the ceramic member.

Growing community of inventors

Nagoya, Japan

Isao Oda