Browse Prior Art Database

Verification of C-Ring Heat Treatment

IP.com Disclosure Number: IPCOM000036454D
Original Publication Date: 1989-Oct-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 2 page(s) / 48K

Publishing Venue

IBM

Related People

Eve, JL: AUTHOR [+3]

Abstract

This article concerns a means for determining whether or not C-rings have undergone a required heat treatment step. The disclosed measurement technique subtly detects the lack of the particular heat treatment by application of a ratio of other measured lot properties.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 54% of the total text.

Page 1 of 2

Verification of C-Ring Heat Treatment

This article concerns a means for determining whether or not C-rings have undergone a required heat treatment step. The disclosed measurement technique subtly detects the lack of the particular heat treatment by application of a ratio of other measured lot properties.

C-ring seals (metal sealing rings) are employed in the fabrication of modules to ensure the proper sealing and long-term hermaticity of the product. The sealing ring is preferably made of lead-plated INCONEL*, which, when formed by a proprietary process, assumes a rectangular ring shape having rounded corners, as illustrated in Fig. 1. In the rectangular-forming step, the corners are strain hardened much more than the sides, making necessary a second heat treatment (anneal) of the part to erase that differential, as shown in Fig. 2. Hypothetical ring seal hardness is a function of these process steps and is followed by age hardening to further strengthen the ring. Absence of a second anneal at this stage has been found to reduce the reliability of the sealing function and requires that a verification be established prior to final polishing, plating, etc., operations on the part.

(Image Omitted)

Fig. 3 illustrates a C-ring under compression. The most highly stressed region is indicated by 1. A plot of force per unit seal length versus displacement, for an unplated C-Ring, is shown in Fig. 4. It should be noted from this plot that the force-displacement characteristic shows a reversible elastic region 2 to be succeeded by a non-reversible plastic region 3. During the latter, the plastic zone is found...