Dynamic pressure bearing (10), including: a green compact (10′), as a base material, of raw material powder including metal powder capable of forming an oxide coating; and dynamic pressure generating portions (A1 and A2) formed through die molding on an inner peripheral surface (8a) forming a radial bearing gap with an outer peripheral surface (2a1) of a shaft to be supported, that is, a shaft member (2). An oxide coating (11) is formed between particles of the metal powder by subjecting the green compact (10′) to steam treatment, and the dynamic pressure bearing (10) has a radial crushing strength of 150 MPa or more.

Frangible firearm projectiles, firearm cartridges containing the same, and methods for forming the same. The firearm projectiles are formed from a compacted mixture of metal powders that includes zinc and iron powders and which may include an anti-sparking agent. The compacted mixture is heat treated for a time sufficient to form a plurality of discrete alloy domains within the compacted mixture. The frangible firearm projectile may be formed by a mechanism that includes vapor-phase diffusion bonding and oxidation of the metal powders and that does not include forming a liquid phase of any of the metal powders or utilizing a polymeric binder. A majority component of the frangible firearm projectile may be iron. One or more of zinc, bismuth, tin, copper, nickel, tungsten, boron, and/or alloys thereof may form a minority component of the frangible firearm projectile. The anti-sparking agent may include a borate, such as boric acid.

A method for densifying a surface of a powder metal part, includes blending a plurality of powdered metals to form a powder metal blend, actuating an upper punch and a lower punch to apply pressure to the powder metal blend to compact the powder metal blend, sintering the compacted powder metal blend in an oven, forming the compacted powdered metal blend into the powder metal part, heating a portion of the surface of the powder metal part, and densifying the portion of the surface of the powder metal part for a predetermined period of time after the portion of the powder metal part is heated to a predetermined temperature.

A method for densifying a surface of a powder metal part, includes blending a plurality of powdered metals to form a powder metal blend, actuating an upper punch and a lower punch to apply pressure to the powder metal blend to compact the powder metal blend, sintering the compacted powder metal blend in an oven, forming the compacted powdered metal blend into the powder metal part, heating a portion of the surface of the powder metal part, and densifying the portion of the surface of the powder metal part for a predetermined period of time after the portion of the powder metal part is heated to a predetermined temperature.

In molding a compact having portions of an equal thickness on opposite sides of a through-hole, an advancing speed of a holder holding a powder material is adjusted before the holder is advanced and retracted over a die cavity of a die. Specifically, a first preparation of determining in advance a relation between the advancing speed of the holder and a packing density of the powder material packed in the die cavity at each of the portions to be of an equal thickness of the compact on opposite sides of the through-hole is made; and, based on the relation determined in the first preparation, the advancing speed of the holder is adjusted to a speed at which the packing density becomes uniform. Thus, the packing density of the powder material packed in the die cavity can be uniformized, so that the dimensional accuracy of the molded compact can be improved.

In molding a compact having portions of an equal thickness on opposite sides of a through-hole, an advancing speed of a holder holding a powder material is adjusted before the holder is advanced and retracted over a die cavity of a die. Specifically, a first preparation of determining in advance a relation between the advancing speed of the holder and a packing density of the powder material packed in the die cavity at each of the portions to be of an equal thickness of the compact on opposite sides of the through-hole is made; and, based on the relation determined in the first preparation, the advancing speed of the holder is adjusted to a speed at which the packing density becomes uniform. Thus, the packing density of the powder material packed in the die cavity can be uniformized, so that the dimensional accuracy of the molded compact can be improved.

A preparation process of a novel drill shank for an IMPACT gun drill, including: manufacturing a mold and a forming block, wherein a forming blind hole is formed in a middle of the mold, the forming block is inserted into the forming blind hole, a wire pipe is disposed in the mold, a feed port is formed in the forming block, a heating cavity is formed in a forming block lateral face and a forming post; manufacturing the forming block with a 2Cr25Ni20 material; injecting tin bronze powder and iron powder into the forming blind hole, starting vibration pressing by the forming block; inputting direct and pulse current to communicate with the metal powder and heat the metal powder at a same time; forming a drill shank blank after 2-3 min, taking out the drill shank blank; removing an adsorbing agent from the drill shank blank by an extraction method.

A powdery-material feeding device is configured to feed a powdery material to a compression-molding machine configured to obtain a molded product by filling a die bore with the powdery material and to compress the powdery material with punches. The powdery-material feeding device includes a detector configured to detect a biologically-originated foreign matter mixedly contained in the powdery material to be fed to the compression-molding machine, and a controller configured to control to remove the powdery material mixedly containing the biologically-originated foreign matter detected by the detector to avoid feeding of the powdery material mixedly containing the biologically-originated foreign matter to the compression-molding machine, or to control to stop the feeding of the powdery material to the compression-molding machine.

A powdery-material feeding device is configured to feed a powdery material to a compression-molding machine configured to obtain a molded product by filling a die bore with the powdery material and to compress the powdery material with punches. The powdery-material feeding device includes a detector configured to detect a biologically-originated foreign matter mixedly contained in the powdery material to be fed to the compression-molding machine, and a controller configured to control to remove the powdery material mixedly containing the biologically-originated foreign matter detected by the detector to avoid feeding of the powdery material mixedly containing the biologically-originated foreign matter to the compression-molding machine, or to control to stop the feeding of the powdery material to the compression-molding machine.

The present invention relates to an apparatus and a method for manufacturing a soft magnetic composite using ultrasonic vibration and a soft magnetic composite manufactured using the ultrasonic vibration. More specifically, the present invention relates to the apparatus for manufacturing a soft magnetic composite using ultrasonic vibration including: a die that has a putting-in space as an open space in which a powder material is put; a punch set that is inserted into the putting-in space and presses the powder material; an ultrasonic vibration applying unit including ultrasonic vibrators which are arranged along a circumference of an outer die surface of the die and are provided to come into contact with the die; a main body that is positioned below the die and is formed to slide around the die toward an outer circumference; and a control unit that controls a frequency of the ultrasonic vibrators depending on a degree of pressure of the punch set, a method for manufacturing a soft magnetic composite using ultrasonic vibration, and a soft magnetic composite manufactured using the same.