Ngk Insulators, Inc.

Keiji Kawasaki

Koji Fushimi

Shinichi Miwa

Hideyoshi Tsuruta

Yutaka Unno

Tadaaki Matsuhisa

Yasufumi Aihara

Kiminari Kato

Hisakazu Okajima

Michio Sekiguchi

Shigeo Nishioka

Hisayoshi Kato

An electrostatic chuck includes; a base made of ceramics, in which an electrode generating electrostatic attractive force is embedded; a cooling member which contains metal; a bonding material which bonds the base and the cooling member to each other; a gas providing passage which penetrates the base, the bonding material, and the cooling member; and an engagement member and a bolt member, which are fixing members mechanically fixing the base and the cooling member to each other.

Electrostatic chuck

A heating apparatus for a semiconductor producing system is provided, including a heater having a mounting face, an opposed back face, a first resistance heating element, a second resistance heating element provided along substantially the same plane as the first heating element, a first terminal connected with the first heating element and a second terminal connected with the second heating element. A supporting member is fixed to the back face of the heater. First and second power supply means are respectively connected with the first and second terminals and contained in an inner space of the supporting member. A conductive connector connects the first heating element and the first terminal but not the second heating element. The first heating element is provided in a first zone, the second heating element is provided in a second zone, and the conductive connector is provided in the plane and the second zone.

Heating apparatus

A ceramic guide for a rolling line, used for wire rod transfer in a rolling line, which has a cylindrical contour and a throughhole for wire rod transfer. The throughhole includes a tapered hole and a straight hole of constant diameter, the tapered hole being provided at the wire rod inlet side of the guide. This ceramic guide, when used in a rolling line, is less liable to cause seizure with a wire rod and has higher durability.

Ceramic-made guide for rolling line

A ceramic jig for hot rolling is a sintered body consisting essentially of Si.sub.3 N.sub.4, a sintering aid and trace amounts of impurities. In the ceramic jig, crystallization is made among the Si.sub.3 N.sub.4 grains, and a crystalline phase among the grains comprises 80% or more of a J phase, 10% or less of an H phase and 5% or less of a K phase. A reaction of a jig component with iron and water can be inhibited, and the wear of the jig at the time of rolling can be reduced. The seizure of the jig on a steel material does not occur, so that scratches on products can be remarkably reduced.

Silicon nitride jig for hot rolling

A hydraulic tappet includes a cam sliding portion, a skirt portion and a spring holding portion. The structure has an arrangement that the cam sliding portion is made of ceramic and oil is reserved in the spring holding portion. There is provide a hydraulic tappet capable of efficiently using motive power from a crank shaft, reducing transmission loss and improving the efficiency of the engine.

Hydraulic tappet

An ultrasonic testing method for detection of flaws in a ball-shaped material to be tested using an ultrasonic probe, wherein a test frequency f (MHz) of the probe and a radius of curvature r (mm) of a tip portion of the probe satisfy the relationship 50 mm.ltoreq.r.sqroot.f.ltoreq.60 mm, and wherein the radius of curvature r (mm) of the tip portion and the diameter D (mm) of an oscillator of the probe satisfy the relationship 0.35 mm.ltoreq.D/r.ltoreq.0.50 mm. The method enables detection of surface and internal flaws in materials, particularly ceramic ball hearings having a diameter ranging from several tens of millimeters down to 10 mm or below.

Ultrasonic testing method for balls

A method for measuring surface roughness of an end face of a honeycomb structure having a plurality of cells by using a stylus having a width corresponding to a width of at least two cells. A honeycomb surface roughness-measuring element, which is adapted for the measurement of a surface roughness of an end face of a honeycomb structure, includes a stylus having a tip, said tip having a widened edge with a width of 2 to 8 mm and a radius of curvature of 1 to 5 .mu.m.

Method for measuring surface roughness of honeycomb structures and

An ultrasonic testing method includes the steps of transmitting an ultrasonic wave from a probe to a test article, detecting an internal flaw in the test article by a reflected flaw echo from the internal flaw, and determining the shape of the detected flaw by comparing and analyzing frequency components of the transmitted ultrasonic wave and the reflected flaw echo.

Ultrasonic testing method

An ultrasonic testing method for detecting flaws of balls for structural members comprises rotating a ball to be tested in an ultrasonic wave transmitting medium. At least two focus-type ultrasonic probes are provided and arranged so as to cover nonoverlapping flaw-detecting regions on and/or inside the ball. Flaws in the ball are detected by sending ultrasonic waves from the probes toward the ball. An apparatus for detecting flaws of balls comprises a ball holding portion for rotatably holding the ball to be tested, at least two focus-type probes for detecting flaws and at least two probe mounting portions for mounting the probes thereof so that respective axes of the probes are each capable of being set eccentrically relative to the center of the ball and wherein the focal positions of the probes are variable.

Ultrasonic testing method for detecting flaws of balls for structural

An ultrasonic testing method for detection of flaws in a material to be tested having a curved surface portion by use of an ultrasonic probe, wherein a center axis of curvature of the curved surface portion of the material to be tested and the center axis of the probe are set in an eccentric relationship so that the angle of refraction of an ultrasonic wave is 90.degree., and the probe comprises a tip portion having a curved surface of the same kind as the curved surface portion of the material to be tested and a radius of curvature of from 1.0 to 3.0 times the radius of curvature of the curved surface portion of the material to be tested. The method enables detection of internal flaws in, particularly, a spherical or cylindrical body formed of a ceramic and used as a bearing member.

In a method of detecting defects formed in a surface or in the vicinity thereof of a ball of a bearing by means of an ultrasonic wave, the ball and a probe for projecting an ultrasonic wave toward the ball and receiving an ultrasonic wave reflected from the detects are arranged in water in such a manner that a center axis of the probe is deviated from a normal axis of the ball which passes through a center of the ball and extends in parallel with the center axis of the probe by such a displacement amount that the ultrasonic wave refracted by the ball propagates along the surface of ball. The ball is rotated about a horizontal axis perpendicular to the normal axis, and the ball and probe are rotated relative to each other about a center axis of the ball which is perpendicular both to the normal axis and horizontal axis of the ball, so that the whole surface of the ball is scanned automatically with the ultrasonic wave.

Detecting flaws formed in surfaces of rotating members with ultrasonic

An ultrasonic testing method comprises steps of transmitting an ultrasonic wave from a probe to a test article, detecting an internal flaw in the test article by a reflected flaw echo from the internal flaw, and deciding a condition of the detected flaw by comparing and analyzing frequency components of the transmitted ultrasonic wave and the reflected flaw echo. The probe has a curved tip surface which is the same kind as that of a curved incident surface of the test article and has a radius of curvature of 0.5.about.2.0 times the radius of curvature of the curved incident surface of the test article.

An ultrasonic flaw detecting method able to detect defects of structural balls arranged in an ultrasonic transmitting medium with the aid of reflecting ultrasonic echoes transmitted from an ultrasonic flaw detecting probe immersed in the ultrasonic transmitting medium. The ball to be tested is arranged on two sets of ball driving rollers and the driving rollers are driven to rotate the ball during the test. An ultrasonic flaw detecting apparatus comprises ball driving rollers each including a shaft portion and a ball driving portion having a circular shape in a section perpendicular to the shaft portion to rotate the ball arranged on the ball driving rollers when the ball driving rollers are rotated, and an ultrasonic flaw detecting probe adapted to rotate about the ball for transmitting ultrasonic waves to the ball to scan defects of the ball.

Ultrasonic flaw detecting method and apparatus for structural balls

A ceramic radial turbine rotor made of a ceramic material having a strength s (kg/mm.sup.2) includes blade tips having a thickness t (mm). A product st.sup.2 of strength s and t.sup.2 (square of t) is representative of resistance to breakage of the rotor to foreign objects colliding against blades of the rotor. The product st.sup.2 fulfills a relation st.sup.2 .gtoreq.5.times.10.sup.4 vm+33. In this case, v is a circumferential speed of tip ends of inducers of blades of the rotating rotor when the blades are damaged by steel balls having a mass m (kg) colliding against the blades in a steel ball collision test of blades of a ceramic radial turbine rotor, and vm is a product of v and m.

Ceramic radial turbine rotor

Method of effecting a spin-testing of a turbocharger rotor with its shaft portion fixed to a simulation attachment assembly consisting of components parts which include a thrust bearing, a spacer, a sleeve or compressor rotor, and a lock nut, wherein an integral composite member is formed from at least two parts of the component parts. The testing device includes the attachment assembly with the integral composite member, and a bearing housing for supporting the turbocharger rotor and the attachment assembly rotatably as a unit.

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Nagoya, Japan

Keiji Kawasaki