Preparation of Al_2O_3 Nano-particles Reinforced Fe-based Composite Materials via In-situ Synthesis

摘要

Al_2O_3 reinforced iron based composite were prepared via in-situ synthesis with aluminum nitrate, citric acid and iron powder as raw materials, a little C and Mo as additive. The influences of the contents of Al_2O_3, C and Mo on the microstracture and micro-hardness of the Fe based composites were characterized by XRD, SEM, TEM and micro-hardness tester. The results showed that the Fe-based composite materials with high bonding strength between matrix and Al_2O_3 can be prepared by in situ synthesis method. The best ratio of the nine Al_2O_3 particles reinforced Fe-based composite materials in three groups is 3vol. % C, 5vol. % or 7vol. % Al_2O_3, sintering temperature is 1300°C and quenching temperature is 900°C. The microstructure of the matrix without C addition is fcrrite before and after quenching;;the microstracture of the matrix with C addition is pearlite before quenching, and the microstructure become to martensite after quenching, the (X-Al_2O_3 and FeC_3 are reinforced phases. The microstructure of the matrix with Mo addition is ferrite and FeAl_2O_4 before and after quenching.