Use of alumina alone or with silica as sintering aid for boron carbide
Abstract
Abstract THE INVENTION DISCLOSE A METHOD OF FORMING SHAPED ARTICLES FROM BORON CARBIDE WHICH INVOLVES COLD MOLDING A POWDER MIXTURE OF BORON CARBIDE AND FROM 3/4 TO 6% ALUMINA AND, WHEN THE BORON CARBIDE CONTAINS FREE CARBON, UP TO 3% OF A SILICA SOURCE THEREIN TO A PREFORM HAVING A GREEN DENSITY OF AT LEAST 50% OF THE THEORETICAL DENSIY OF BORON CARBIDE. THE PREFORM IS THEN SINTERED AT A TEMPERATURE IN EXCESS OF ABOUT 2100*C. TO PREVENT WARPAGE OF THE PREFORM DURING SINTERING A PRESSURE NOT TO EXCEED 10 P.S.I. CAN BE APPLIED DURING SINTERING. SHRINKAGE OF THE PREFORM DURING THE SINTERING TREATMENT CREATES A FINAL SHAPED ARTICLE HAVING A DENSITY IN EXCESS OF ABOUT 90% OF THEORETICAL DENSITY.
Inventors
- 👤 Paul F Jahn
Bibliographic Details
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| 11.5 Years (Year 12) | 1983-01-03 | 1983-07-05 | 1984-01-04 | $7700.00 | Window Closed / Lapsed |