Propagation of impact-induced cracks in brittle materials

Abstract

Vibrational energy is applied through a probe into a pre-scored brittle sheet, separating the sheet along the score line, such as flat or domed glass. Separation times are less than 1 second with smooth edge quality. The sheet may be in the form of a moving ribbon of sheet glass to which a vibrational load is applied in a direction transverse to the score line to promote crack propagation along the score line. The controller steers the probe according to the selected vibration frequency, amplitude, contact velocity, impact contact force, alignment with the scribe line, etc., depending on material properties and structures, and optimal process parameters.

Description

[0001] This application claims the rights and interests of the United States Patent Application No. 11 / 588051, entitled "IMPACT INDUCED CRACK PROPAGATION IN A BRITTLEMATERIAL" filed on October 26, 2006, and its complete content Incorporated into this article. Technical field [0002] The present application relates to the separation of brittle sheets, and more specifically, to the generation of cracks along the score line and the propagation of cracks due to the application of mechanical energy on the brittle materials. Background technique [0003] There are two conventional techniques that can be used to cut or shape sheets of brittle materials such as glass, amorphous glass, glass ceramics or ceramic materials to form a piece of material with the desired structure or geometric characteristics. [0004] The first conventional method is to mechanically scribe the sheet, that is, to scribe the surface of the brittle material with a hard device such as a diamond tip or a tungsten tip...

AI Technical Summary

Problems solved by technology

However, this separation is slower and it is often difficult to control crack growth

The second laser beam also creates thermal cracks and high residual stresses

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