Corning Incorporated

The United States of America as Represented by the United States Energy

Theodore R Kozlowski

George Halsey Beall

David J Kerko

David W Morgan

Michael Henry Wasilewski

Frederick E Noll

Joseph Ference

William T Brydges, Iii

Theresa A Winer

J Mario Quintal

A method of protecting a metal against embrittlement when the metal is exposed to carbon or sulfur at an elevated temperature, the method comprising forming a thin, adherent, continuous coating of a glass on the surface of the metal prior to exposure to carbon or sulfur at an elevated temperature.

Method of protecting metal

Slow fading photochromic glass

This invention is concerned with glass-ceramic articles having compositions within a very narrowly-delimited area of the MgO-Al.sub.2 O.sub.3 -B.sub.2 O.sub.3 -SiO.sub.2 field and having alpha-quartz and sapphirine as the principal crystal phases, resulting from nucleation through a combination of TiO.sub.2 and ZrO.sub.2. Upon contacting such articles with lithium ions at an elevated temperature, said lithium ions will replace magnesium ions on a two Li.sup.+-for-one Mg.sup..sup.+2 basis within the crystal structures, thereby providing a unitary glass-ceramic article having an integral surface layer wherein the principal crystal phase is a lithium-stuffed beta-quartz solid solution. That transformation of crystal phases results in compressive stresses being set up within the surface layer as the articles are cooled. Through the careful control of composition, crystallization treatment, and the parameters of the replacement reaction in the crystal structures, a tremendous degree of stored elastic energy can be developed within the articles such that they will demonstrate frangibility when fractured but will not exhibit undesirable spontaneous breakage and/or spalling.

Method for making glass-ceramic articles exhibiting high frangibility

Growing community of inventors

Horseheads, NY, United States of America

Theodore R Kozlowski