Backers having glass particulates for electron beam hole drilling
AssigneeUnited Technologies Corporation
InventorsJohn J. Brennan, Lester W. Jordan
Life of this patent
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Abstract
Backers for electron beam hole drilling contain glass particulates with a binder. For nickel base alloys, the glass particulates have at least 7 weight percent low temperature constituent, with a melting point less than 1500.degree. C., and a balance of high temperature constituent having a vaporization point of greater than 2000.degree. C. at 1 atmosphere. Softening points of the glasses exceed 700.degree. C. and preferably are in the range 800.degree.-1000.degree. C. A useful glass will have a viscosity of at least about 10 Pa.multidot.s when it melts. More preferred silicate glasses contain by weight percent at least 8Al.sub.2 O.sub.3, 9CaO, and 3B.sub.2 O.sub.3.
Claims10
In energy beam drilling, such as electron beam drilling, of uniformly shaped holes in a metal workpiece with the use of a backer containing ceramic particulate and a binder in contact with the exit surface of the workpiece, the improvement which comprises using a backer containing a glass particulate having a softening temperature greater than 700.degree. C. and at least 7 weight percent of a low temperature constituent together with a high temperature constituent, the low temperature constituent converting at least in part to a gas and the high temperature constituent converting at least in part to a liquid during drilling.
Dependencies are inferred from the claim text.