Fe-Al微叠层复合材料的制备及界面表征

Preparation and Interface Characterization of Fe-Al Micro-laminated Composites

将多层纯铁和纯铝薄板交替叠放,采用“热轧复合—冷轧减薄—合金化热处理”工艺流程制备了Fe-Al金属/金属间化合物微叠层复合材料(Fe-Al MIL),研究了合金化温度对该复合材料微观组织、相组成、相变及力学性能的影响.结果表明:所制备的Fe-Al微叠复合材料Fe/Al界面结合状态良好;随合金化温度的升高,化合物层厚度随之增加,当温度低于Fe-Al固-半固态反应温度655℃时,Fe_(2)Al_(5)和FeAl是化合物层的主要物相,而高于655℃时,则会在化合物层和Fe金属界面处出现少量交替分布的FeAl_(3)和Fe_(3)Al;DSC曲线上呈现出~559,~571和~667℃三个放热峰,分别代表FeAl_(3),Fe_(2)Al_(5)和FeAl的相转变;固-固和固-液合金化后得到的Fe-Al MIL力学性能较差,均易发生分层断裂现象,而固-半固态合金化热处理后其力学性能最佳.

Layers of pure iron and pure aluminum sheets were alternately stacked,and the Fe-Al metal-intermetallic-laminate(MIL)composites were prepared by the process of hot-rolling compound,cold-rolling reduction and alloying treatment.The effects of alloying temperature on the microstructure,phase composition,phase transformation,and mechanical properties of the Fe-Al MIL composite were investigated.The results show that the prepared Fe-Al MIL composite has a good Fe/Al interface bonding state.As the alloying temperature increases,the thickness of the compound layer increases.When the temperature is lower than the Fe-Al solid/semi-solid reaction temperature of 655℃,Fe 2Al 5 and FeAl are the main phases in the compound layers.When the temperature is above 655℃,a small amount of FeAl 3 and Fe 3Al appear alternately at the interface between the compound layer and the Fe matrix.The DSC curve shows there are three exothermic peaks of~559,~571 and~667℃,which represent the phase transitions of FeAl_(3),Fe_(2)Al_(5),and FeAl,respectively.The mechanical properties of the Fe-Al MIL composites obtained after solid-solid and solid-liquid alloying are poor,and both are prone to delamination fracture.The best performance of Fe-Al MIL composite can be achieved after the solid/semi-solid alloying treatment.