Different proportions of two kinds( -80 + 100 mesh and -325 mesh) of water atomized pure iron powder were taken to study the different effect on the apparent density, flowahility, compressibility and com- pression process. The results showed that the apparent density of iron varied in the range of 2.84 - 3.42 g./cm3 and the flowability in 20 - 31 s/50 g by controlling the composition of different particle size. Compared to coarse powder, when 25 % fine powder was added in the coarse powder, the green density increased at the low pressure ( 〈300 MPa) and decreased under high pressure (〉I 300 MPa).When the fine powder's ratio in- creased to 75%, the green density increased. Further more, the fine powder's ratio increased to 100%, the value of green density is decreased. At low pressure ( 〈 300 MPa) , the mechanism of compact densification is the slippage and rearrangement of particle ; Under high pressure ( ≥ 300 MPa), however, the mechanism of corn-pact densification is the plastic deformation of powder.%为了研究粒度组成对水雾化铁粉松装密度、流动性、压缩性及压制过程的影响,将-80＋100目和-325目两种粒径的水雾化纯铁粉以不同比例搭配进行研究.结果表明：通过控制不同的粒度组成,铁粉松装密度在2.84～3.42 g/cm3内变化、铁粉流动性在20～31 s/50 g内变化;与纯粗粉样品A相比,在粗粉中添加质量分数25%细粉的样品B在低压（〈300 MPa）下压坯密度增加,高压（≥300 MPa）时压坯密度减少;细粉质量分数为75%时的样品D与样品C相比,压坯密度均增加;全部采用-325目细粉的样品E与样品D相比,压坯密度均降低.当压制压力低于300 MPa时,压坯致密化主要由颗粒的滑移、重排决定;当压制压力高于300 MPa时,压坯致密化主要以粉末的塑性变形为主.
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