(中南大学粉末冶金研究院粉末冶金国家重点实验室，长沙 410083)
摘 要: 在Fe-2%Ni-1%Cu-0.6%C混合料中加入了少量微细Fe2O3粉末作为烧结助剂，研究Fe2O3粉末的添加量对混合料的压缩性、烧结合金的密度和强度以及氧和碳含量等的影响，研究微细Fe2O3粉末对合金的助烧结行为。结果表明：混合料中Fe2O3含量大于0.3%(质量分数)时，会导致成形生坯密度下降；当Fe2O3添加量为0.3%时，烧结合金的密度最高，经1120 ℃烧结0.5和1 h后，合金的抗弯强度比同等烧结条件下未添加Fe2O3样品的分别提高6.5%和4.2%。少量Fe2O3粉在材料烧结时对碳含量损失率的影响较小，然而可以降低烧结体中的氧含量。在压坯的烧结过程中，Fe2O3还原后于750 ℃左右开始加速基体颗粒间的连结，虽然在1050 ℃以上时微细粉的助烧结作用减弱，但烧结体中孔隙更趋于球化。
关键字: 铁基粉末冶金；Fe-2%Ni-1%Cu-0.6%C；Fe2O3粉；烧结
（State Key Laboratory of Powder Metallurgy, Research Institute of Powder Metallurgy,
Central South University, Changsha 410083, China）
Abstract:Fe-2%Ni-1%Cu-0.6%C powder premix was prepared with minor ultrafine Fe2O3 powder as a sintering aid. The effects of Fe2O3 addition on compressibility of the mixture, sintered density, strength of the alloy and its oxygen and carbon content were studied. The assist-sintering behavior of ultrafine Fe2O3 powder was also investigated. The results show that the green density decreases when the Fe2O3 content is above 0.3%, while the highest density of sintered alloy is obtained with 0.3% Fe2O3 addition.And the flexural strengths of the alloy sintered at 1120 ℃ for 0.5 h and 1 h increase by 6.5% and 4.2%, respectively, compared with that of sample without Fe2O3 powder addition. Minor ultrafine Fe2O3 powder has slight effect on the loss rate of C content of the sintered alloy, and yet the oxygen content is reduced. It is observed that the metallurgy bonding between matrix particles is accelerated from about 750℃ for the reduction of Fe2O3 particles. Though the assist-sintering function of ultrafine powder weakens when the temperature is above 1050 ℃, the pole shape in the sintered alloy is apt to spheroidize.
Key words: iron-based powder metallurgy; Fe-2%Ni-1%Cu-0.6%C; Fe2O3 powder; sintering
