处理工艺对Fe-Al合金粉末成形性及生坯压溃强度的影响

Effect of treatment process on the formability of Fe-Al alloy powders and the crushing strength of green compacts

为了提高Fe-Al合金粉末的压制成形性和生坯压溃强度,分析了氢气还原和真空退火工艺对Fe-Al合金粉末形貌和性能的影响,研究了原始粉末和经过处理后粉末所制管坯的成形率。结果发现,经氢气还原和真空退火处理后,粉末形貌变化不大,粉末性能提高,生坯压溃强度增强,成形性得到改善;尤其是经真空退火粉末的性能得到极大提高,氧的质量分数由0.5%低到0.2%,松装密度由1.82 g·cm^(-3);降低到1.64 g·cm^(-3),显微硬度由HV 260降低到HV 158,压缩比由63%降低到56%,生坯压溃强度由2.0 MPa提高到2.7 MPa,粉末成形性得到极大改善。在批量化压制长管坯时,对原始粉末预先进行真空退火处理,长管生坯数量成品率由50%提高至100%,产品成本降低。

To improve the formability of Fe-Al alloy powders and the crushing strength of green compacts, the effects of hydrogen reduction and vacuum annealing on the morphology and properties of the Fe-Al alloy powders were analyzed, and the forming rate of the tube billets made from the original powders and the treated powders were studied. The results show that, after the hydrogen reduction and vacuum anneal treatment, the morphology of the original Fe-Al alloy powders has little change, the powder properties are enhanced, and the crushing strength and formability of the green compacts are improved. Especially after the vacuum anneal treatment, the powder properties are significantly enhanced, oxygen mass fraction decrease from 0.5% to 0.2%, apparent density decrease from 1.82 g·cmcm^(-3) to 1.64 g·cm^(-3),microhardness decrease from HV 260 to HV 158, compression ratio decrease from 63% to 56%, crushing strength of the green compact increase from 2.0 MPa to 2.7 MPa, the formability is greatly improved. In the quantity production of long tube billets, the vacuum annealing pretreatment of the original Fe-Al alloy powders can effectively increase the qualified rate of the long tube billets from 50%to 100%and reduce the product cost.