铁基粉末的恒流电致快速烧结

Fast Sintering of Iron-Based Powders with Constant Electric Current

采用恒流电致烧结方法对铁基混合粉末进行了快速烧结,通过对不同通电时间烧结样品的显微组织、断口形貌进行分析,并对其电阻、密度及各项机械性能进行测试,研究了粉末的电致烧结行为.结果表明:在较低的测量温度下,粉末中出现了烧结颈,并发生了铁-碳的互扩散,且颗粒界面有局部熔化的迹象,证实电致烧结初期在颗粒接触区域存在局部高温;随着烧结过程的进行,烧结体的密度、横向断裂强度和显微维氏硬度均呈上升趋势,电阻则逐渐降低.

Iron-based mixed powders were fast consolidated via the sintering with constant electric current. To investigate the sintering behavior of the powders, the microstructure and fracture surface morphology of the samples sintered at various durations were analyzed, and the electrical resistance, density and mechanical properties of the samples were measured. It is found that the formation of sintering necks and the diffusion of carbon into the iron matrix occur at a relatively low experimental temperature. In addition, some molten metal can be seen on the particle interfaces, which means that a local high-temperature region is generated in the particle contacting regions at the earlier sintering stage. With the development of the sintering process, the density, transverse rupture microhardness of the sintered sample increase, while the electrical resistance gradually decreases. strength and