In a die for compressing and sizing a sintered body at straight portions, upper taper portions are provided on a die upper portion and a core rod upper portion, and the straight portions are provided at a die lower portion and a core rod lower portion. The die upper portion and the core rod upper portion have Young's moduli higher than the die lower portion and the core rod lower portion. The die upper portion and the core rod upper portion are made of materials having Young's moduli that are at least 50 GPa higher than that of the sintered body. The sintered body can be densified with a smaller ironing margin. Since the sintered body is ironed without being compressed, by the upper taper portions and the core rod upper portion having high Young's moduli, the die is prevented from breaking and being abraded due to ironing.

The invention relates to a device (10) for the layered production of a three-dimensional workpiece, comprising: a build space (30) in which the workpiece is manufacturable by selectively solidification of raw material powder layers; an irradiating system (20) which is adapted to selectively solidify the raw material powder layers in the build space (30) by emitting a processing beam; at least one calibrating structure (36); a sensor arrangement (25) which is adapted to detect an irradiation of the calibrating structure (36) by the irradiating system (20); and a control unit (26) which is adapted to calibrate the irradiating system (20) on the basis of detection information of the sensor arrangement, wherein the calibrating structure (36) is arranged outside the build space (30). The invention also relates to a method for calibrating an irradiating system of a device for the layer-by-layer manufacture of a three-dimensional workpiece.

The invention relates to a device (10) for the layered production of a three-dimensional workpiece, comprising: a build space (30) in which the workpiece is manufacturable by selectively solidification of raw material powder layers; an irradiating system (20) which is adapted to selectively solidify the raw material powder layers in the build space (30) by emitting a processing beam; at least one calibrating structure (36); a sensor arrangement (25) which is adapted to detect an irradiation of the calibrating structure (36) by the irradiating system (20); and a control unit (26) which is adapted to calibrate the irradiating system (20) on the basis of detection information of the sensor arrangement, wherein the calibrating structure (36) is arranged outside the build space (30). The invention also relates to a method for calibrating an irradiating system of a device for the layer-by-layer manufacture of a three-dimensional workpiece.

The invention relates to a method for producing a gear worm (12) which is located in particular on an armature shaft (14) of an electromotive drive unit (10), wherein firstly a worm gear (20) having screw flanks (22) axially opposite one another on a longitudinal axis (18) is formed by means of a rolling tool, and subsequently a groove structure (24) which is concentric about the longitudinal axis (18) is formed on the screw flanks (22) by means of an additional process step. The invention also relates to a gear worm (12) produced according to the method according to the invention, and to a transmission drive unit (10) containing such a gear worm (12).

It has been found that metal parts having rough surfaces can be manufactured by (1) compacting a metal powder under high pressure in a mold to make a green part, wherein at least one face of the mold is roughened by electrical discharge machining to have an R.sub.a of 10 to 200 micro-inches, as measured with a profilometer having a stylus tip, (2) heating the green metal part to a temperature of at least 1500 F. to sinter the green metal part to produce the metal part having at least one rough surface, wherein the rough surface has an R.sub.a which is within the range of 10 to 200 micro-inches, as measured with a profilometer having a chisel tip, and (3) optionally, buffing, classifying, deburring and/or washing the metal part. This method can be beneficially used in manufacturing clutch plates, pressure plates, and cam shaft sprockets.

It has been found that metal parts having rough surfaces can be manufactured by (1) compacting a metal powder under high pressure in a mold to make a green part, wherein at least one face of the mold is roughened by electrical discharge machining to have an R.sub.a of 10 to 200 micro-inches, as measured with a profilometer having a stylus tip, (2) heating the green metal part to a temperature of at least 1500 F. to sinter the green metal part to produce the metal part having at least one rough surface, wherein the rough surface has an R.sub.a which is within the range of 10 to 200 micro-inches, as measured with a profilometer having a chisel tip, and (3) optionally, buffing, classifying, deburring and/or washing the metal part. This method can be beneficially used in manufacturing clutch plates, pressure plates, and cam shaft sprockets.

In order to supply sufficient amount of oil to one or more sliding surfaces and to prevent the supplied oil from moving from the sliding surface(s) to an inside so as to achieve lower friction and improve sliding performance of a bearing, in an oil-impregnated sintered bearing 1, sliding surfaces 3 supporting an outer circumferential surface of a shaft 11 and an oil supply surface 4 in which a diameter is larger than that of the sliding surfaces 3 are formed on an inner circumferential surface of a bearing hole 2 into which the shaft 11 is inserted, to be adjacent in an axial direction of the bearing hole 2, a height gap d1 between the sliding surfaces 3 and the oil supply surface 4 is not less than 0.01% and not more than 15% of an inner diameter of the sliding surfaces, a surface opening percentage of the sliding surfaces 3 is not higher than 10%, a surface opening percentage of the oil supply surface 4 is higher than 10%, and an average circle-equivalent diameter of opening parts of pores on the sliding surfaces is not larger than 20 m.

It has been found that metal parts having rough surfaces can be manufactured by (1) compacting a metal powder under high pressure in a mold to make a green part, wherein at least one face of the mold is roughened by electrical discharge machining to have an R.sub.a of 10 to 200 micro-inches, as measured with a profilometer having a stylus tip, (2) heating the green metal part to a temperature of at least 1500 F. to sinter the green metal part to produce the metal part having at least one rough surface, wherein the rough surface has an R.sub.a which is within the range of 10 to 200 micro-inches, as measured with a profilometer having a chisel tip, and (3) optionally, buffing, classifying, deburring and/or washing the metal part. This method can be beneficially used in manufacturing clutch plates, pressure plates, and cam shaft sprockets.

It has been found that metal parts having rough surfaces can be manufactured by (1) compacting a metal powder under high pressure in a mold to make a green part, wherein at least one face of the mold is roughened by electrical discharge machining to have an R.sub.a of 10 to 200 micro-inches, as measured with a profilometer having a stylus tip, (2) heating the green metal part to a temperature of at least 1500 F. to sinter the green metal part to produce the metal part having at least one rough surface, wherein the rough surface has an R.sub.a which is within the range of 10 to 200 micro-inches, as measured with a profilometer having a chisel tip, and (3) optionally, buffing, classifying, deburring and/or washing the metal part. This method can be beneficially used in manufacturing clutch plates, pressure plates, and cam shaft sprockets.

A method for producing a liquid phase sintered aluminum alloy member, includes: a compacting process of compacting a raw material powder containing an aluminum alloy powder containing at least one element selected from Si, Mg, Cu, and Zn, with the balance being Al and unavoidable impurities to form a green compact; a sintering process of subjecting the green compact to liquid phase sintering to give a sintered body; a softening process of subjecting the sintered body to a heat treatment to give a softened material; a straightening process of sizing the softened material to give a straightened material; and an aging process of subjecting the straightened material to a heat treatment to give an aged material in which precipitates are formed.