Abstract: A sintered SiC body is produced by forming a thermoplastically moldable ceramic composition comprised of sinterable silicon carbide powder and binder, thermoplastically molding the ceramic composition into a body, embedding the body in nominally spherical particles having a density greater than 80% of the particle's theoretical density and being selected from the group consisting of polycrystalline silicon carbide, free carbon-coated polycrystalline silicon carbide, free carbon and mixtures thereof, baking the embedded body to remove the binder therefrom, recovering and sintering said baked body.

Abstract: A silicon carbide body with a density of at least 85% is machined to required specification and then fired at a temperature ranging from 1400.degree. C to 2100.degree. C in a firing atmosphere ranging in pressure from 10.sup..sup.-3 torr to 25 torr to increase its fracture strength by at least 10%.

Abstract: A temperature probe measures temperature changes of biological tissue while he tissue is being irradiated with microwaves. The temperature probe is completely nonmetallic to minimize perturbation of the microwave field, and the structure of the probe includes a plurality of optic fibers which carry light to and from a reflective liquid crystal film. The liquid crystal is enclosed in a housing at the tip of the probe which is in contact with the biological tissue, and the liquid crystal undergoes changes in absolute reflectance proportional to the temperature changes of the tissue. The optic fibers are gathered in a bundle with a first portion of the bundle transmitting light from a light generation device to the liquid crystal and the remainder of the bundle transmitting reflected light from the crystal back to a photo transistor. The reflected light received by the photo transistor is converted into an electrical signal and displayed as a representation of temperature.