Study on high performance Fe-Al2O3 composites produced with Bayan Obo Ore by carbothermal reduction
In this study,the Fe-Al2O3 composite was prepared by carbothermal reduction method with Bayan Obo iron concentrate as main raw materials,meanwhile,the activated carbon was added as reducing agent.The effects of different amounts of reductants on the reduction process,microstructure and properties of composites were stud-ied.The results of XRD show that sample C1 is mainly composed of Al2O3,Fe,spinel and a small amount of iron oxide due to low reducing agent content.The diffraction peaks of spinel and iron oxide disappear with the increase of reducing agent dosage.Furthermore,there is a small amount of anorthite contained in the samples C1-C4,which gradually decreased with the increase of reducing agent dosage.SEM analysis shows that the metal phases are uni-formly distributed in the alumina matrix in granular form,and a small amount of glass phases exist at the grain boundary of alumina.Fracture mechanism analysis shows that the metal phase absorbs energy through plastic de-formation to improve the mechanical properties of the composites.The optimal properties of the sample are as fol-lows:density of 4.12 g/cm3,porosity of 0.62％,linear shrinkage of 17.55％,bending strength of 308 MPa,hardness of 13.02 GPa,acid resistance of 93.55％,alkali resistance of 98.85％.This study provides a low-cost and cleaning process for the preparation of high performance composite materials from natural minerals.
Bayan Obo Orecompositecarbothermal reductionmechanical propertypowder metallurgy
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