Leland Stanford Junior University

Gte Products Corporation

The Morgan Crucible Company Plc

Sptek

Toshimasa Oyama

Oleg D Sherby

Jeffrey Wadsworth

Howard Mizuhara

David J Kepniss

Dong W Kum

The present invention is directed to brazing filler metals that can be used in the infiltration brazing of porous matrix materials without the need for a flux. The brazing filler metals contain two different Group II metals and a third metal of Group 9 and 10. A particular brazing filler metal of the invention contains silver, copper, and nickel. The invention is also directed to composite materials formed by infiltration of the brazing material into a porous matrix, and to methods for preparing the composite materials. The invention is further directed to composite articles fabricated from composite materials, including steel bearings or bushings, and to methods of preparing the composite articles.

Silver-copper-nickel infiltration brazing filler metal and composites made therefrom

A high gold content brazing alloy containing titanium is used to braze a platinum electrode to a ceramic cylinder.

Platinum electrode bonded to ceramic

An ultrahigh carbon steel having a composition of carbon in an amount of from about 0.8 weight percent up to the maximum solubility limit of carbon in austenite, aluminum in an amount of from about 0.5 to about 10 weight percent, an effective amount of a stabilizing element acting to stabilize iron carbide against graphitization, and the balance iron. Preferably, the aluminum is present in an amount of from about 0.5 to about 6.4 weight percent and the stabilizing element is chromium. The steel has excellent ductility and is readily hot, warm and cold worked without cracking. It is particularly useful in superplastic forming operations, and may be processed to a suitable microstructure by any technique which reduces its grain size to about 10 microns or less, and preferably to about 1 micron. Such a very fine grain size is readily acheived with the steel, and the aluminum and stabilizing additions act to retain the fine grain size during superplastic processing.

Ultrahigh carbon steels containing aluminum

An ultra high carbon steel having a composition of carbon in an amount of from about 0.8 weight percent up to the maximum solubility limit of carbon in austenite; silicon in an amount of from about 3 to about 7 weight percent; an effective amount of a stabilizing element acting to stabilize iron carbide against graphitization in the presence of silicon; and the balance iron. Preferably, the silicon is present in an amount of about 3 weight percent, and the stabilizing element is chromium. The ultra high carbon steel may be processed to a form suitable for subsequent superplastic forming by any technique which reduces its grain size to about 10 microns or less, and preferably to about 0.4 to about 2 microns. The silicon and the stabilizing element act to produce a stable iron carbide particle array to retain the fine grain size during superplastic processing, and to increase the eutectoid temperature so that superplastic processing may proceed at high strain rates and low stress levels at elevated temperature.

Ultra high carbon steel alloy and processing thereof

An ultrahigh carbon steel consisting of a structure formed by divorced eutectoid transformation with or without accompanying deformation such that substantially no pearlite is formed, having a fine grained iron matrix stabilized by cementite in spheroidized form. A method for processing the steel including heat treatment and mechanical working to form spheroidized proeutectoid carbide particles then reheating the steel for a time such that the carbon is not uniformly distributed in the austentite so that upon cooling, with or without accompanying deformation, a divorced eutectoid transformation occurs leading to a structure of spheroidized cementite in a fine ferrite grain matrix.

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Palo Alto, CA, United States of America

Toshimasa Oyama