公开(公告)号：US3644607A

公开(公告)日：1972-02-22

申请号：US3644607D

申请日：1969-12-18

Applicant: TEXAS INSTRUMENTS INC

Inventor： RAQUES RODNEY A ,  GRAY FOSTER L

IPC: C04B35/14 ,  C04B41/32 ,  B28B11/04 ,  C23C11/08

CPC classification number: C04B35/14

Abstract: AN ARTICLE COMPOSED OF A METAL OXIDE HAVING A COMPOSITION OF TOW OR MORE OXIDES THE CONCENTRATION OF WHICH CAN PREFERENTIALLY OR SELECTIVELY BE VARIED THROUGHOUT ITS THICKNESS. THE METHOD FOR MAKING THE ARTICLE INCLUDES VAPOR PAHSE HYDROLYSIS OF A METAL HLAIDE DEPOSITION OF THE RESULTANT METAL OXIDE ONTO A DEPOSITION SURFACE. IN AN EXEMPLARY MODE SILICON DIOXIDE IS DEPOSITED ON A DEPOSITION MANDREL UNTIL A PREDETERMINED THICKNESS IS LAID DOWN. THEREAFTER A MIXTURE OF SILICON DIOXIDE AND TITANIUM DIOXIDE ARE DEPOSITED ON THE PREVIOUSLY BUILT-UP SILICON DIOXIDE LAYER. THE METAL OXIDE ARTICLE THUS FORMED IS A POROUS,AMORPHOUS STRUCTURE. FOR MOST USES THIS STRUCTURE IS THEN SINTERED TO FORM A FUSED METAL OXIDE STRUCTURE. THIS METHOD OF FORMING AN ARTICLE ALLOWS PREFERENTIAL VARIANCE OF THE THERMAL EXPANSION OF A FUSED SILICA CRUCIBLE OR TUBE THROUGHOUT ITS WALL THICKNESS.