4886638 METHOD FOR PRODUCING METAL CARBIDE GRADE POWDERS Joseph Penkunas, Theodore Smith, Jack L Burwick assigned to GTE Products Corporation A method is disclosed for producing metal carbide grade powders, which comprises dry milling metal carbide powder which can be tungsten carbide, titanium carbide, tantalum carbide, niobium carbide, vanadium carbide, chromium carbide, and combinations thereof to increase the surface area of the powder particles to result in essetially all of the powders being converted to single crystals, forming a mixture of the resulting dry milled carbide powder, a binder metal which can be cobalt, nickel, and combinations thereof, and a wax, while heating the carbide powder, the binder metal and the wax to a temperature above the melting point of the wax and maintaining the temperature to result in a uniform distribution of the wax on the carbide and binder metal particles, forming a slurry of the mixture and water, attritor milling the slurry at a temperature below the melting point of the wax, and removing the water from the resulting attritor milled mixture and aggiomerating the mixture to produce the metal carbide grade powder wherein a densified article made therefrom exhibits essentially no pores that are greater than about 10 micrometers in diameter after sintering at from about 1350 degrees C. to about 1540 degrees C.
4887496 METHOD OF MAKING DRILLS, ENDMILLS AND OTHER ROTATING-AND-CUTTING TOOLS Yoshinob Kobayashi, Yamoto shi, Kanagawa ken, Japan Disclosed is a method of making drills, endmills and other rotating-and-cutting tools comprising the steps of: extruding super-hard metal powder into a spiral rod; sintering the spiral rod; forming a-ferrous metal powder layer around the rear end of the spiral rod sinter; and heating and then cooling the ferrous metal powder layer in such a way that voids may be caused to appear in the ferrous metal powder layer, which is integrally connected to the spiral rod sinter to make up its shank. Thanks to the existence of the voids in the
shank layer, any inner strain will be dissipated, assuring that crack-free products result.
4880755 SIALON CUTTING TOOL COMPOSITION Pankaj K Mehrotra assigned to Kennametal Inc A sialon ceramic material comprising a ceramic core selected from alpha-prime-sialon, betaprime-sialon, and an intergranular phase and, optionally substantially substantially inert refractory phases. The sialon ceramic material has an alloyed surface layer with a substantially increased aluminum and oxygen content.
4889276 METHOD AND APPARATUS FOR FORMING AND BONDING METAL ASSEMBLIES Gilbert CadweU, Paul M Phillips assigned to Rohr Industries Inc A method and apparatus for forming and bonding metal assemblies using an internally heated chamber. The parts can be both superplastic formed and diffusion bonded to other parts. A closable chamber contains a heating element near the chamber center. A ceramic die at least partially surrounding the heating element has a forming surface toward the heating element. The inner wall of the chamber is lined with a pressure bladder. A granular material, conical ceramic support, or extensible bladder fills the space between ceramic die and chamber inner wall. With the chamber closed, the heater is activated while an inert gas under pressure is introduced between heater and die and the bladder if used is pressurized. The bladder or packed granules support the outer die surface while the gas pressure presses metal parts on the die forming surface against the die. The metal parts are formed and bonded together by the substantially isostatic forces thereon. The heat is concentrated on the parts, leaving the chamber walls cold. When forming is complete, the chamber interior is cooled and the die is removed and broken away from the formed assembly. Parts can be formed and bonded rapidly with a considerable energy saving over conventional isostatic pressing ovens.