Preparation Of Fe-based Cermets By In-situ Aluminothermic Carbothermal Reduction Of Baiyun Ebo Iron Concentrate

Al2O3-Fe-based cermet composites show excellent performance as tool materials and wear-resistant materials.However,the current conventional powder metallurgy method makes the material preparation cost higher,and at the same time causes the ceramic particle interface pollution,which seriously affects the mechanical properties of the material.Exploring a new way to prepare high-performance composite materials at low cost is of great significance to promote its application.In the in-situ reduction method,the reinforcement is nucleated and spontaneously grown in the metal matrix.Therefore,the surface of the reinforcement is free of pollution,the compatibility between the matrix and the reinforcement is good,and the interface bonding strength is high;meanwhile,compared with other preparation methods,Simple process.In this study,combined with China's rich iron ore resources,Al2O3-Fe composites were prepared by hot-pressing sintering process using aluminothermic and carbothermal in-situ synthesis methods,and Al2O3-reinforced iron-based cermets were successfully prepared using vacuum hot-pressing sintering technology.Through XRD,SEM,and flexural and hardness testing methods,the effects of ball milling time on the particle size and powder extraction rate of the raw materials and the ratio of aluminum-carbon ratio to the in-situ reduction of the reinforced ironbased cermets were analyzed and summarized influences.The results show that the reinforcement phases of Al2O3 iron-based cermets synthesized in situ using Baiyun Ebo iron concentrate are Al2O3 and Fe phases,and the matrix structure of Al2O3 reinforced iron-based composites synthesized in situ by iron concentrates is distributed as coarse block particles;The properties of the prepared Al2O3 reinforced iron-based composites are relatively good.When the ratio of aluminum to carbon is 1.5 / 1 and the hot pressing pressure is 25 MPa,the best comprehensive mechanical properties of the material are 736 MPa flexural strength and 552 Vickers hardness.The development of this topic has important practical significance for the research and industrial application of in-situ synthetic cermets using minerals as the main raw materials.