Back to results
US 4,743,511 AGranted
Graded refractory cermet article
AssigneeMinnesota Mining and Manufacturing Company
InventorsHarold G. Sowman, David R. Kaar
Life of this patent
Estimating the term…
Abstract
This invention provides a shaped, graded, cermet article comprising at least one continuous ceramic phase and at least one discontinuous metal phase, the ratio of ceramic/metal being controlled and varied over the thickness of the article. The ceramic phase preferably is microcrystalline.
Claims11
A process for making a shaped, graded cermet article comprising the steps:
- a. providing an aqueous solution containing soluble metal salts, carboxylates, and oxide sols, dispersible colloids, or mixtures thereof,
- b. concentrating said mixture to a viscous concentrate,
- c. shaping the resulting viscous concentrate into a desired formed article,
- d. gelling the formed article to provide a green non-refractory shaped article,
- e. drying and firing said green article at a temperature sufficient to convert it to a refractory ceramic article, and
- f. heating said fired article in a reducing atmosphere to provide said shaped cermet article,
- said article being a shaped, non-fused, cermet article comprising at least one continuous ceramic phase and containing at least one metal phase of discrete particles separated from each other, the ratio of ceramic/metal being controlled and gradually and continuously varied over the depth of the article so as to provide an article wherein the density of metal is greatest in all the exterior surface portions and decreases towards the innermost portions.
4 more elements
Dependencies are inferred from the claim text.