| 摘要 |
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 500μm average particle size in which the spherical powder of 20 to 200μaverage 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 <1.65 sec/cm<3> , the roundness is >=0.7 and the average acicular ration <1.45.
|
