Patent•
Powder for powder metallurgy and powdery mixture for powder metallurgy
16 Nov 1999-
TL;DR: In this article, the problem of increasing the forming density of a sintered body, to impart sufficient strength and to improve the dimensional precision therein, was solved by using the one with a nonspherical shape of specified average particle size bonded by bonding strength at a degree to be cracked to the primary particulate powder by compressive force at the time of compression molding.
Abstract: PROBLEM TO BE SOLVED: To increase the forming density of a sintered body, to impart sufficient strength thereto and to improve the dimensional precision therein, in which the primary particulate powder of powder for powder metallurgy in an approximately spherical shape has the spherical shape of average particle size, by using the one with a nonspherical shape of specified average particle size bonded by bonding strength at a degree to be cracked to the primary particulate powder by compressive force at the time of compression molding. SOLUTION: This is powder for powder metallurgy in an approximately spherical shape of 40 to 500 μm average particle size in which the spherical powder of 20 to 200 μ average particle size is bonded by bonding force at a degree in which the powder for powder metallurgy can be cracked to the primary particulate powder. As an index showing the shape close to the spherical of the secondary particulate powder, apparent density AND, powder fluidity, roundness and an acicular ratio are given and preferably, the apparent density is 83 to 100% of tap density TD (AD/TD), the powder fluidity is , the roundness is >=0.7 and the average acicular ration <1.45.
Citations
More filters
Patent•
24 Feb 1998TL;DR: An iron-based powder mixture for powder metallurgy is provided in this article, which can produce a sintered material having by far higher machinability and sliding properties than conventional Sintered materials, and also a material containing alloy elements but having adaptability to sizing even after sintering.
Abstract: An iron based powder mixture for powder metallurgy is provided which can produce a sintered material having by far higher machinability and sliding properties than conventional sintered materials, and also a sintered material containing alloy elements but having adaptability to sizing even after sintering; it comprises an atomized iron powder comprising S in a content of 0.03 to 0.30 wt%, Mn in a content of 0.05 to 0.40 wt% and the balance Fe and incidental impurities, to which is added one or more than one B-containing compound powder selected from boron nitride (BN), boric acid (H3BO3), boron oxide (B2O3) and the like in an amount of 0.001 to 0.3 wt% expressed as B, and incorporated with an MnS powder in an amount of 0.05 to 1.0 wt%, optionally alloyed partially with or prealloyed with Ni, Mo and Cu.
76 citations
Patent•
21 Aug 2008
TL;DR: In this paper, a manufacturing method for forming sintered parts by adding a plastic binder to a raw material powder and using die compaction was proposed, by which a product having irregularity can be manufactured with uniform density without causing buckling and breakage of a punch.
Abstract: PROBLEM TO BE SOLVED: To provide a manufacturing method, which is a method for forming sintered parts by adding a plastic binder to a raw material powder and using die compaction, by which a product having irregularity can be manufactured with uniform density without causing buckling and breakage of a punch SOLUTION: The granulated powder is prepared by subjecting a metal powder or a mixture of the metal powder and graphite powder in an amount of ≤14 mass% based on the metal powder to binding with a binder and granulation, wherein the metal powder is an iron-base alloy powder having a particle size passing through a 250 mesh sieve and also having ≥37 Mg/m 3 tap density; the binder consists of at least one selected from the group consisting of cellulose, higher fatty acid, derivative thereof and wax; the binder occupies 5 to 30 vol% of the granulated powder; the granulated powder has a size passing through a 35 mesh sieve and has ≥20 Mg/m 3 apparent density A method for manufacturing the sintered parts uses the above granulated powder COPYRIGHT: (C)2008,JPO&INPIT
3 citations