粘结化铁基粉末的高速压制成形与烧结行为研究

研究了采用粉末改性处理和高速压制相结合的技术制备高密度铁基粉末冶金材料的工艺。所用的粘结化铁基粉末的名义成分(质量分数)为Fe-1.5Ni-0.5Cu-0.5C;重点研究了压制能量和粉末塑化改性对压坯密度的影响,以及高密度压坯的烧结致密化行为。结果表明:粘结化铁基粉末具有较高的流动性(25.1s/50g)和松装密度(3.2～3.4g/cm3)。未经塑化改性处理的粉末随着压制速度的增加,压坯密度提高缓慢,在8.7m/s高压制速度下,压坯密度为7.37g/cm3。塑化改性处理粉末具有优异的塑性变形能力,压坯密度随着冲击能量的增加而迅速增大,在6.2～8.7m/s的压制速度范围内,压坯密度为7.07～7.62g/cm3。经过8.7m/s高速压制和1 150℃烧结后,烧结体密度达到7.51g/cm3,相对密度为96.5%。

Study on high velocity compaction and sintering behaviour of bonding treated ferrous powder

The novel technology used to fabricate high-density powder metallurgy materials by the combination of powder modification and high velocity compaction was investigated.The nominal composition of the bonding treated proprietary powder is Fe-1.5Ni-0.5Cu-0.5C(weight percent).The main focus of this work is on the elucidation of the influence of compaction energy and power modification on the green density,and the sintering behaviour of the high-density compacts.The results indicate that the proprietary powder exhibits homogeneous composition,excellent flowability(25.1s/50g) and relatively high apparent density(3.2-3.4g/cm3).As for the powder without plasticizing,the green density increases slowly with increasing compaction velocity,and the green density is only 7.37g/cm3 at the high compaction velocity of 8.7m/s.The powder after plasticizing exhibits excellent plastic deformation ability,and the green density increases rapidly with increasing compaction energy.In the compaction velocity range of 6.2-8.7m/s,green density of 7.07-7.62g/cm3 are achieved.Under the compaction velocity of 8.7m/s and the sintering temperature of 1 150℃,the highest density of 7.51g/cm3 was obtained,and the relative density was 96.5%.