Ablative-resistant dielectric ceramic articles
AssigneeThe United States of America as represented by the Secretary of the Navy
InventorsRoy W. Rice, William J. McDonough, Stephen W. Freiman, John J. Mecholsky, Jr.
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Abstract
A tough, ablative-resistant, dielectric ceramic material is constructed using powder metallurgy techniques. The composite comprises a boron nitride particulate phase immersed in an Al.sub.2 O.sub.3 matrix. The boron nitride particles are preferably 3-5 microns in size, and create the capability of sustaining thermal strains without generating the thermal stresses that lead to material failure. The composite displays superior mechanical strength characteristics.
Claims6
A hot pressed ceramic composite possessing a high degree of resistance to failure from thermal fracture consisting essentially of from 10 to 70 volume percent of hexagonal boron nitride particles which have a plate-like shape of about 1-10 microns in dimension, with their thickness being a small fraction of their dimension, uniformly dispersed in a powdered alumina matrix of 30 to 90 volume percent.
Dependencies are inferred from the claim text.