Process for making a dense ceramic workpiece
AssigneeDrexel University
InventorsMichel W. Barsoum, Tamer El-Raghy
Life of this patent
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Abstract
A dense ceramic workpiece is made by a process of combining a powdered 312 component, e.g., Ti.sub.3 SiC.sub.2, with a powdered component that is soluble in the 312 component, e.g., TiSi.sub.2 in Ti.sub.3 SiC.sub.2, forming the mixture into a green body, heating the green body under pressureless sintering conditions to a temperature above a point at which a liquid is formed but below the melting point of the 312 compound to yield a dense ceramic workpiece, and thereafter cooling the dense 312 ceramic workpiece.
Claims28
A process for making a dense ceramic workpiece which comprises
- (i) mixing a powdered Ti.sub.3 XC.sub.2 component, where X is selected from the group consisting of Si, Ge, Al and Ga, and a powdered component that is soluble in a solid phase of Ti.sub.3 XC.sub.2, the soluble component having a melting point below that of Ti.sub.3 XC.sub.2 and being present in an amount of from about 0.1% to about 20% by volume based on the volume of the Ti.sub.3 XC.sub.2 component, to provide a homogeneous mixture;
- (ii) forming the homogeneous mixture into a green body;
- (iii) heating the green body under a non-oxidizing atmosphere without the application of significant pressure to a temperature above a point at which a liquid is formed in the green body but below the melting point of Ti.sub.3 XC.sub.2 ;
- (iv) maintaining the heated green body at said temperature for a period of time sufficient to produce a ceramic workpiece with at least 80% of theoretical density;
- and
- (v) cooling the Ti.sub.3 XC.sub.2 ceramic workpiece below said temperature at which a liquid is formed in the green body.
A process for making a dense ceramic workpiece which comprises
- (i) mixing titanium-, carbon- and silicon-containing components in powdered form and in stoichiometric amounts sufficient for formation of Ti.sub.3 SiC.sub.2, to provide a powdered Ti.sub.3 SiC.sub.2 component mixture;
- (ii) preparing a homogeneous mixture by mixing said powdered Ti.sub.3 SiC.sub.2 component mixture with a powdered component thermodynamically compatible with Ti.sub.3 SiC.sub.2 and selected from the group consisting of TiSi.sub.2 and Ti.sub.5 Si.sub.3, the thermodynamically compatible component being in powdered form and being present in amounts of from about 0.1% to about 20% by volume based on the volume of the powdered Ti.sub.3 SiC.sub.2 component mixture;
- (iii) forming the homogeneous mixture into a green body;
- (iv) heating the green body under a non-oxidizing atmosphere without the application of significant pressure to a temperature above a point at which a liquid is formed in the mixture but below the melting point of Ti.sub.3 SiC.sub.2 ;
- (v) maintaining the heated green body at said temperature for a period of time sufficient to form a Ti.sub.3 SiC.sub.2 workpiece having at least 80% of theoretical density;
- and
- (vi) cooling the Ti.sub.3 SiC.sub.2 ceramic workpiece below said temperature at which a liquid is formed in the green body.
Dependencies are inferred from the claim text.