微波烧结Fe-2Cu-0.6C合金的保温时间对组织与性能的影响

Effects of Soaking Time on Microstructure and Properties of Microwave Sintering Fe-2Cu-0.6C Alloy

对微波烧结Fe-2Cu-0.6C粉末冶金材料进行了1150℃不同保温时间下的性能和显微组织研究,并与常规烧结试样进行了对比。结果表明:微波烧结保温时间由5min增加至15min,试样的各项性能达到最佳:密度为7.22g/cm3,硬度HRB为78,抗拉强度为416.8MPa,延伸率为5.5%;保温时间延长至20min对试样性能影响不大。微波烧结的性能较常规烧结高。通过金相显微分析表明:微波烧结有着良好的微观结构,即小的、近圆形且均匀分布的孔隙结构,从而也有利于获得细小的晶粒和高的致密度;微波烧结较常规烧结有着更多片状和粒状珠光体,能显著改善其性能。由断口分析可知,常规烧结样品属于脆性穿晶断裂,而微波烧结样品为脆性穿晶断裂和韧窝型的穿晶韧性断裂的混合型断裂。

The properties and microstructure of microwave sintering Fe-2Cu-0.6C alloy at 1150℃ for different soaking time were studied, and compared with that of the conventional sintered samples under the same sintering temperature properties. The results showed the microwave sintered properties were higher than conventional sintered. The properties reached optimal, when the microwave sintering soaking time changed from 5min to 15min. The density was 7.22 g/cm^3, HRB was 78, tensile strength was 416.8 MPa and elongation was 5.5%. But prolonged soaking time to 20min, the properties were not changed. Optical microscopy revealed that microwave sintered sample had finer microstructures, as small, rounded, and uniformly distributed pores, which was advantageous to obtain the tiny crystal grain and high density. There were much flaky and granular pearlite compared with the conventional sintered, so microwave sintering can significantly improve the sample＇s performance. Through fracture analysis, the conventional sintered was brittle intergranular fracture and microwave sintered was mixed fracture made up of brittle intergranular and ductility intergranular fracture.