Abstract: High-strength, fine-grain multi-phase substantially crystalline sintered ceramic bodies are produced by a process comprising the steps of cold pressing, followed by sintering at a high temperature, the temperature increase to maximum sintering temperature being accomplished by the use of a heating rate in excess of about 100.degree. C./minute.

Abstract: A particulate dispersion of Al.sub.2 O.sub.3, elemental non-diamond carbon and a titanium member selected from the group consisting of elemental titanium, TiH.sub.2 and mixtures thereof is formed into a compact and sintered producing a ceramic composite having a minimum Rockwell A hardness of about 92 and being comprised of an Al.sub.2 O.sub.3 phase and a substoichiometric titanium carbide phase.

Abstract: A self-lubricating cemented carbide cutting tool of special utility in titanium machining having a copper coating bearing a film of copper iodide is provided by coating the tool with a layer of copper, heating to bond the copper to the cemented carbide and thereafter reacting the copper with iodine to form the film of desired thickness.

Abstract: A particulate dispersion of Al.sub.2 O.sub.3, elemental non-diamond carbon and a titanium member selected from the group consisting of elemental titanium, TiH.sub.2 and mixtures thereof is formed into a compact and sintered producing a ceramic composite having a minimum Rockwell A hardness of about 92 and being comprised of an Al.sub.2 O.sub.3 phase and a substoichiometric titanium carbide phase.

Abstract: A well-bonded polycrystalline cubic boron nitride body is produced by providing the cubic boron nitride particles with a discontinuous coating of tungsten or molybdenum and then infiltrating them in a mass with molten silicon or silicon-base alloy.

Abstract: A polycrystalline diamond body infiltrated by a silicon atom-containing metal (e.g., silicon alloy) is bonded to a substrate comprising cemented carbide with a barrier of refractory material extending between the diamonds cemented together with silicon atom-containing binder and the substrate substantially precluding migration of the cementing medium (e.g., cobalt) from the carbide substrate into contact with the silicon atom-containing bonding medium in the diamond body. The process comprises subjecting a mass of diamond powder, a quantity of silicon atom-containing metal binder material, a cemented carbide body and a barrier made of material selected from the group consisting of tantalum, vanadium, molybdenum, zirconium, tungsten and alloys thereof to the simultaneous application of elevated temperature and pressure.

Abstract: A process for simultaneously (1) cementing particles of cubic boron nitride (CBN) together, (2) bonding particles of ceramic together to form a substrate, or support layer, for the cemented CBN particles and bonding the cemented CBN particles to the substrate is described. Substrates consisting essentially of compatible combinations of ceramic particles and an aluminum-base bonding medium are disclosed.

Abstract: An improved laser-assisted machining process has special application to difficult-to-machine materials such as the titanium alloys and high temperature superalloys. A layer of material to be removed by a cutting tool is made weaker by drilling a series of holes using a pulse laser beam ahead of the cutting process so that the tool removes the rest of the weaker material with relative ease. There is a decrease of cutting forces, breakage of the chip to a manageable size, and reduced tool wear.

Abstract: A well-bonded polycrystalline cubic boron nitride body is produced by providing the cubic boron nitride particles with a discontinuous coating of tungsten or molybdenum and then infiltrating them in a mass with molten silicon or silicon-base alloy.

Abstract: A process for simultaneously cementing diamond fines together and bonding the cemented diamonds to a silicon-silicon carbide composite is described. During the process the silicon-silicon-carbide composite furnishes silicon for the cementing and bonding function and the silicon-silicon carbide composite provides for the structural stability of the resulting article. The process comprises placing a quantity of diamond powder and a mass of silicon-silicon carbide composite adjacent to each other, packing such material to form a stabilized geometry, heating the stabilized geometry in an inert atmosphere, and simultaneously applying pressure thereto.

Abstract: A mass of diamond crystals in contact with a mass of eutectiferous silicon-rich alloy and a silicon carbide ceramic substrate are disposed in a container and placed within a pressure transmitting powder medium. Pressure is applied to the powder medium resulting in substantially isostatic pressure being applied to the container and its contents sufficient to dimensionally stabilize the container and its contents. The resulting shaped substantially isostatic system of powder-enveloped container is hot-pressed whereby fluid eutectiferous silicon-rich alloy is produced and infiltrated through the interstices between the diamond crystals and contacts the contacting face of the silicon carbide substrate sufficiently producing, upon cooling, an adherently bonded integral composite.

Abstract: A mass of diamond crystals in contact with a mass of eutectiferous silicon-rich alloy and a silicon nitride ceramic substrate are disposed in a container and placed within a pressure transmitting powder medium. Pressure is applied to the powder medium resulting in substantially isostatic pressure being applied to the container and its contents sufficient to dimensionally stabilize the container and its contents. The resulting shaped substantially isostatic system of powder-enveloped container is hot-pressed whereby fluid eutectiferous silicon-rich alloy is produced and infiltrated through the interstices between the diamond crystals and contacts the contacting face of the silicon nitride substrate sufficiently producing, upon cooling, an adherently bonded integral composite.

Abstract: An adherently bonded polycrystalline diamond body is produced by forming a charge composed of a mass of diamond crystals in contact with a mass of eutectiferous silicon-rich alloy wherein the alloy is in contact or in association with hexagonal boron nitride, confining such charge within a reaction chamber, subjecting the confined charge to a pressure of at least 25 kilobars, heating the pressure-maintained charge to a temperature sufficient to melt the alloy and at which no significant graphitization of the diamond occurs whereby the alloy infiltrates through the interstices between the diamond crystals producing said body.

Abstract: A mass of diamond crystals in contact with a mass of eutectiferous silicon-rich alloy and a silicon nitride ceramic substrate are disposed in a container and placed within a pressure transmitting powder medium. Pressure is applied to the powder medium resulting in substantially isostatic pressure being applied to the container and its contents sufficient to dimensionally stabilize the container and its contents. The resulting shaped substantially isostatic system of powder-enveloped container is hot-pressed whereby fluid eutectiferous silicon-rich alloy is produced and infiltrated through the interstices between the diamond crystals and contacts the contacting face of the silicon nitride substrate sufficiently producing, upon cooling, an adherently bonded integral composite.

Abstract: A mass of diamond crystals in contact with a mass of eutectiferous silicon-rich alloy and a silicon carbide ceramic substrate are disposed in a container and placed within a pressure transmitting powder medium. Pressure is applied to the powder medium resulting in substantially isostatic pressure being applied to the container and its contents sufficient to dimensionally stabilize the container and its contents. The resulting shaped substantially isostatic system of powder-enveloped container is hot-pressed whereby fluid eutectiferous silicon-rich alloy is produced and infiltrated through the interstices between the diamond crystals and contacts the contacting face of the silicon carbide substrate sufficiently producing, upon cooling, an adherently bonded integral composite.

Abstract: A mass of diamond crystals in contact with a mass of eutectiferous silicon-rich alloy are disposed in a container and placed within a pressure transmitting powder medium. Pressure is applied to the powder medium resulting in substantially isostatic pressure being applied to the container and its contents sufficient to dimensionally stabilize the container and its contents. The resulting shaped substantially isostatic system of powder-enveloped container is hot-pressed whereby fluid eutectiferous silicon-rich alloy is produced and infiltrated through the interstices between the diamond crystals producing, upon cooling, an adherently bonded integral body.

Abstract: A cavity of predetermined size is formed in a compressed pressure transmitting powder medium, a mass of diamond crystals in contact with a mass of elemental silicon are disposed within the cavity and additional pressure transmitting powder is placed over the cavity and its contents producing a powder-enveloped cavity. Pressure is applied to the powder medium resulting in substantially isostatic pressure being applied to the cavity therein and its contents sufficient to dimensionally stabilize the cavity and its contents. The resulting shaped substantially isostatic system of powder-enveloped diamond and silicon is hot-pressed to liquefy and infiltrate the silicon through the interstices between the diamond crystals producing, upon cooling, an adherently bonded integral body.

Abstract: A mass of diamond crystals contacting a mass of elemental silicon are confined within a pressure-transmitting medium. The resulting charge assembly is subjected to a pressure of at least 25 kilobars causing application of isostatic pressure to the contacting masses which dimensionally stabilizes them and increases the density of the mass of diamond crystals. The resulting pressure-maintained charge assembly is heated to a temperature sufficient to melt the silicon and at which no significant graphitization of the diamond occurs whereby the silicon is infiltrated through the interstices between the diamond crystals producing, upon cooling, an adherently bonded integral body.

Abstract: A mass of diamond crystals in contact with a mass of eutectiferous silicon-rich alloy are disposed in a container and placed within a pressure transmitting powder medium. Pressure is applied to the powder medium resulting in substantially isostatic pressure being applied to the container and its contents sufficient to dimensionally stabilize the container and its contents. The resulting shaped substantially isostatic system of powder-enveloped container is hot-pressed whereby fluid eutectiferous silicon-rich alloy is produced and infiltrated through the interstices between the diamond crystals producing, upon cooling, an adherently bonded integral body.

Abstract: A mass of cubic boron nitride (CBN) crystals, aluminum or aluminum alloy and a silicon carbide ceramic substrate are disposed in a container which is placed within a pressure-transmitting powder medium. Pressure ranging from about 20,000 psi to about 200,000 psi is applied to the powder medium resulting in substantially isostatic pressure being applied to the container and its contents. To the resulting shaped substantially-isostatic system of powder-enveloped container, heat and pressure are applied simultaneously whereby the aluminum or aluminum alloy is liquefied and infiltrated through the interstices between the CBN crystals and diffused into the contacting face of the silicon carbide substrate sufficiently to produce, upon cooling, an adherently bonded integral composite.