Abstract: The invention relates to a method of making a three-dimensional object, comprising the steps of: (a) forming a powder material layer (10) of inorganic material; (b) irradiating an optical beam (L) on a predetermined portion of the powder material layer (10) to form a first sintered layer (11) and integrate the first sintered layer (11) with a second sintered layer (11) just below the first sintered layer (11); (c) repeating the steps (a) and (b) to form a sintered block (B) united with a plurality of the first and second sintered layers (11), the sides of the sintered block (B) including a concave portion (g); (d) removing an excess portion (17) from a surface of the sintered block (B); and (e) repeating the steps (c) and (d) with respect to the sintered block (B) from which the excess portion (17) is removed, in order to make a target shape of a three-dimensional object united with a plurality of the sintered blocks (B).

Abstract: To make a three-dimensional object, an optical beam is first irradiated on a predetermined portion of a powder layer to form a sintered layer, which is then covered with a new powder layer. The optical beam is again irradiated on a predetermined portion of the new powder layer to form another sintered layer that has been united with the underlying sintered layer. These processes are repeatedly carried out to form a plurality of sintered layers united together. When the second lower density layer is formed on the first higher density layer, a powder material layer for the lower density layer is formed at a predetermined thickness so as to have a thickness suitable for sintering condition and then the powder material layer is sintered to form the lower density layer.

Abstract: A three-dimensional object of a desired shape is made by irradiating an optical beam on a metal powder layer to form a sintered layer and by laminating such sintered layer one above another. A metal powder composition for use in making such a three-dimensional object includes an iron-based powder material, a nickel and/or nickel alloy powder material, a copper and/or copper alloy powder material, and a graphite powder material. The graphite powder material acts to enhance the wettability during melting and to reduce microcracks during solidification.

Abstract: A three-dimensional object is manufactured by filling and hardening a powder material around a core. A powder material is first filled and layered around the core, and a beam is then selectively irradiated on the layer of powder material to form a hardened layer united with the core. These steps are repeated to form a plurality of hardened layers around the core, thereby manufacturing the three-dimensional object having the core embedded therein.

Abstract: To make a three-dimensional object, an optical beam is first irradiated on a predetermined portion of a powder layer to form a sintered layer, which is then covered with a new powder layer. The optical beam is again irradiated on a predetermined portion of the new powder layer to form another sintered layer that has been united with the underlying sintered layer. These processes are repeatedly carried out to form a plurality of sintered layers united together, which have a size greater than that of a target shape of the three-dimensional object. A surface region of a shaped object formed by then is removed during the formation of the plurality of sintered layers.

Abstract: In order for a surface of a three-dimensional sintered object to be smoothly finished by removing unwanted portions and an excessively sintered growth formed during sintering to form sintered layers, the three-dimensional sintered object is formed by repeating successive processes of dispensing a powdery material and directing an optical sintering beam to the powdery material to form the sintered layer, until a required number of integral laminated bodies are formed. During the formation of the integral laminated bodies, trimming is applied to a first zone different from a second zone in which each laminated body is formed, to remove unwanted portions of the respective laminated body.

Abstract: To make a three-dimensional object, an optical beam is first irradiated on a predetermined portion of a powder layer to form a sintered layer, which is then covered with a new powder layer. The optical beam is again irradiated on a predetermined portion of the new powder layer to form another sintered layer that has been united with the underlying sintered layer. These processes are repeatedly carried out to form a plurality of sintered layers united together, which have a size greater than that of a target shape of the three-dimensional object. A surface region of a shaped object formed by then is removed during the formation of the plurality of sintered layers.

Abstract: A cutting tool is provided which includes a steel metal body and a cemented carbide cutting tip secured to the metal body by a metallic layer. The metallic layer has a high-strength metallic portion and a high-toughness metallic portion. The high-strength metallic portion is made of a metal having a thermal expansion rate between a thermal expansion rate of the metal body and the thermal expansion rate of the cutting tip. The high-toughness metallic portion is located between edge portions of a securing region of the metal body and the cutting tip and has toughness larger than that of the high-strength metallic portion.

Abstract: A saw blade preventing "fluff" or "return" of fibers from occurring when used to cut wood or the like object and rendering any finishing work unnecessary is formed with a unique combination of cutting teeth and biting teeth, the biting teeth being disposed, on a cut path mainly by means of the cutting teeth, either on top surface of or in front of each cutting tooth in cutting direction of the saw blade and to have a smaller width than the cutting teeth, for realizing a biting operation by the biting teeth and the cutting operation by the cutting teeth in the same sawing step.

Abstract: A process of debinding a powder compact formed from a mixture of a sinterable powder and an organic binder utilizes a furnace for heating therein the powder compact at a pressure lower than an atmospheric pressure in order to remove an excess amount of the organic binder. A control is made to vary the furnace pressure and/or a heating rate in accordance with a monitored parameter so as to effectively and successfully removed an excess amount of the organic binder which would cause an unacceptable defect in a finished product. The parameter is selected as indicative of a condition of the furnace or a cracked gas being generated by decomposition of the organic binder, and includes, for example, a furnace temperature, density, volume, or the other measurable characteristics of the cracked gas.

Abstract: A process of debinding a ceramic product utilizes a furnace for heating the ceramic product therein in the presence of a surrounding gas so as to remove an organic binder contained in the ceramic product. The ceramic product is continuously heated to an elevated temperature during which the organic binder is decomposed to generate a cracked gas. The process monitors the condition of the cracked gas and controls, depending upon the monitored condition, to vary a temperature gradient at which the ceramic product is heated and at the same time to vary an amount of the surrounding gas being supplied to the furnace in such a manner as to remove the organic binder successfully from within the ceramic product without leaving any unacceptable defect therein.