The Boc Group, Inc.

Richard C Paciej

Shigeki Hayashi

Mark J Kirschner

Edward K Chang

Robert Sherman

Takashi Sakanaka

Yoshiyuki Nakahara

Jeffrey Davidson

Robert E Lewis

Satish S Tamhaukar

The present invention provides a method for surface passivating stainless steel articles against the effects of corrosive materials having activities anywhere from aqueous salt solutions to corrosive gases such as hydrogen chloride and silane. Additionally, after the treatment and exposure of the article to moisture, when the article is subsequently flushed with a dry gaseous fluid, the time that the article takes to exhibit an acceptable moisture outgassing rate is reduced over an untreated article. In accordance with the present invention, the surface to be passivated is flushed with a dry gaseous fluid, chemically non-reactive with the stainless steel and containing essentially no oxygen. During such flushing, the articles is baked and cooled. The baking is accomplished at a predetermined temperature and time (preferably between about 250.0.degree. C. and about 500.0.degree. C. for about 4.0 hours) to effect, within the oxide layer, a reduction in adsorbed moisture and hydroxide content and an increase in chromium content. The article is allowed to cool after the baking step. Such gaseous fluid can comprise argon having a moisture content of no greater than 10.0 ppb and an oxygen content of about 10 ppb. No improvement was seen in a sample in which nitrogen was used. When nitrogen shows no improvement, the article should be flushed with a rare gas during baking which additionally should contain 10 ppb nitrogen or less.

Stainless steel surface passivation treatment

A method of forming a copper circuit pattern on a ceramic substrate. In accordance with the method, first and second layers of copper oxide and copper are applied to the ceramic substrate. Selected regions of the copper are then masked so that unmasked regions are formed on the copper in a configuration of the copper circuit pattern. Masked regions are formed on the copper adjacent the unmasked regions, where copper cannot be plated. The unmasked regions of the copper are plated in a neutral pH solution by a reverse pulse plating process. The masking is then removed and the copper and copper oxide layers are etched so that the copper and copper oxide is removed from the unmasked regions. Thereafter, the remaining copper is direct bonded to the substrate.

Method of forming a copper circuit pattern

The present invention provides an apparatus and method for ultrasonically testing the internal neck-shoulder region of a large number of gas cylinders for radially oriented defects. The apparatus and method includes housing an ultrasonic transducer within a shoe in a predetermined orientation wherein the transducer is wedged at a wedge angle so that ultrasonic pulses travel directly through the shoulder region to the top and bottom of the internal neck-shoulder region and is also outwardly skewed within the shoe at a skew angle such that the radially oriented defects reflect the ultrasonic pulses and produce return echoes. An automated scanner moves the shoe and therefore, the transducer in a predetermined pattern such that the entire internal neck-shoulder region of the gas cylinder is scanned. The scanner is supported by a stand that allows the automated scanner to be rapidly set up on the gas cylinders being tested. A processor activates the transducer to produce ultrasonic pulses, controls the automated scanner and responds to the return echoes for indicating the presence of the radial defects that require the removal of a particular one of the gas cylinders from service.

Ultrasonic testing apparatus and method for rapidly inspecting a large

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Lansdale, PA, United States of America

Richard C Paciej