Heat resisting material and method for producing it

Claim 1

A METHOD OF MAKING AN INTRICATE SHAPED BODY OF SELF-BONDED SILICON NITRIDE DESIGNED TO WITHSTAND HIGH TEMPERATURE AND TO RESIST CREEP AND THERMAL SHOCK AT SUCH TEMPERATURE, COMRPISING THE STEPS OF COMPACTING POWDERED SILICON INTO A BLOCK, PREFIRING THE BLOCK IN AN ATMOSPHERE OF NITROGEN AT A TEMPERATURE IN THE REGION OF 1000*C. FOR A TIME SUFFICIENT TO EFFECT SUCH BONDING OF THE SILICON THAT THE BLOCK CAN BE GRIPPED FRIMLY AND MACHINED WITHOUT PRODUCING DESTRUCTION, MACHINE WORKING THE BLOCK TO THE REQUIRED INTRICATE SHAPE, FIRING THE SHAPED BODY IN AN ATMOSPHERE OF NTROGEN INITIALLY AT A TEMPERATURE BELOW THE MELTING POINT OF SILICON FOR SUFFICEINT TIME TO PRODUCE A RIGID NETWORK OF SILICON NITRIDE RETAINING THE UNCOMBINED SILICON, AND THEN FIRING IN NITROGEN AT A TEMPERATURE ABOVE THE MELTING POINT OF SILICON TO COMPLETE NITRIDING OF THE SILICON.