Patent ID: 6863759
Filing Date: 2005-03-08
Classification: C04B

Abstract:
1. A method for making a unitary silicon carbide composite body, comprising: bringing at least two subunit preforms into contact with one another at a location relative to one another at which said preforms are to be joined, thereby forming a boundary zone between said subunit preforms, each of said preforms being permeable to molten silicon or silicon alloy, and each containing at least some carbon; providing a key comprising a mechanical locking preform containing at least some carbon, and being sufficiently self-bonded as to permit its being green machined; providing a keyway having a size and shape as to engage said mechanical locking preform, and placing said keyway across said boundary zone such that supplying of said key to said keyway will cause a mechanical locking action to occur; placing said mechanical locking preform into said keyway, thereby restraining movement of one subunit preform relative to the other in at least one plane, and thereby forming an assemblage of preforms; providing an infiltrant material comprising silicon; heating said infiltrant material to a temperature above the liquidus temperature of said infiltrant material to form a molten infiltrant material; communicating said molten infiltrant material into contact with at least a portion of said preform assemblage; infiltrating said molten infiltrant material into said preform assemblage, and reacting at least a portion of said silicon with at least a portion of said carbon to form a composite body comprising interconnected silicon carbide and a residual infiltrant phase comprising said silicon distributed throughout said interconnected silicon carbide, thereby forming a unitary silicon carbide composite body.