放电等离子烧结制备铁基合金  

Fabrication of Iron-Based Alloy by Spark Plasma Sintering

作　　者：李小强[1] 梁华星[1] 叶永权[1] 李元元[1] 

机构地区：[1]华南理工大学机械与汽车工程学院,广东广州510640

出　　处：《华南理工大学学报（自然科学版）》2009年第8期140-144,共5页Journal of South China University of Technology(Natural Science Edition)

基　　金：国家"863"高技术计划资助项目(2007AA03Z112);国家"973"计划资助项目(2007CB616905)

摘　　要：采用脉冲+恒流电流烧结方法对Fe-2Cu-2N i-1Mo-0.8C混合粉末进行了快速烧结,通过对不同脉冲电流通电时间烧结样品的显微组织、断口形貌进行分析,并对样品的密度和抗弯强度进行测试,研究了粉末的脉冲+恒流电流烧结行为.结果表明:当脉冲峰值电流、基值电流、占空比和频率分别为3 000 A、360 A、50%和50Hz,空载恒流电流为1 389A时,经脉冲和恒流电流各烧结3m in后,合金的密度和抗弯强度分别达到最大值7.61 g/cm3和1 540MPa;该烧结材料的显微组织以珠光体为主,其中包含块状或网络状分布的铁素体、奥氏体及少数未扩散均匀的合金相;弯曲断口呈现解理、韧窝和沿晶的混合断裂特征;与常规烧结相比,放电等离子烧结不仅能改善烧结材料的性能,而且能提高加工效率.Fe-2Cu-2Ni-lMo-0.8C mixed powders were rapidly consolidated via a pulsed-constant electric current sintering process, and the microstructure and fracture morphology of the alloy sintered at different pulse durations were analyzed. Moreover, the density and bending strength of the alloy were measured and the sintering consolida- tion behavior of the powders was investigated. The results indicate that （1） when the peak current, base current, duty cycle and frequency of the pulsed electric current are respectively 3000A, 360A, 50Hz and 50% , and when the idle constant current is chosen as 1389 A, the alloy sintered with pulsed electric current for 3 rain and with con- stant electric current for another 3 rain is of a density of 7.61 g/cm3 and a bending strength of 1540MPa; （2） the alloy mainly consists of pearlite, with massive or reticular ferrite and austenite as well as few nonuniformly-distributed alloy phase being also observed; （3） the bending fracture is in a mixed mode of cleavage, dimple and interg- ranular fracture; and （4） as compared with the conventional sintering, the spark plasma sintering is more effective in improving the performance and the processing efficiency.

关 键 词：Fe-2Cu-2Ni-1Mo-0.8C合金 放电等离子烧结 显微组织 抗弯强度 

分 类 号：TF124[冶金工程—粉末冶金]