The Preparation Of Fe-Al Alloy With Heat Mechanical Alloy

The Fe-Al intermetallic compound has excellent resistance to high temperature oxidation,hot corrosion resistance and vulcanization resistance,and has low density,high specific strength,good wear resistance and low cost.It can be used as a new generation of medium and high temperature structural materials and stainless steel substitute materials,and has broad application prospects.However,due to the brittleness at room temperature and poor processing properties,its further application is limited.In this paper,Fe3Al powder were prepared by high temperature mechanical alloying method.The effects of the ratio of iron-aluminum materials,ball milling temperature,ball milling time,ball-to-batch ratio and ball mill speed on ball milling products were investigated.The phase and morphology of the milled product were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM)and laser particle size analysis.And a powder having a mass ratio of n(Fe):n(Al):n(Cr)=70:25:5 was prepared by high temperature mechanical alloying.The alloy material was obtained by hot press sintering under an argon atmosphere.The effects of sintering temperature and holding time on the mechanical properties of alloy materials were investigated.The results show that:the Fe powder and Al powder as raw material,high temperature mechanical alloying,aluminum and iron molar ratio n(A1):n(Fe)=28:72,Charge Ratio 20:1,a ball mill speed 40 r/min The pure phase Fe3Al was synthesized at 600? for 40 h.With the increase of sintering temperature,the relative density,flexural strength and fracture toughness of Fe3Al alloys increased first and then decreased.The Vickers hardness is increasing continuously;when the sintering temperature is 1200?,the hot pressing pressure is 40 MPa,and the holding time is 10 min,the density of the Fe3Al alloy material is 6.438 g/cm3,the Vickers hardness is 508 HV,and the flexural strength is 953 MPa,the fracture toughness of 33.67 MPa·m1/2,The Vic-hardness of Fe-Al alloy material doped with Cr is 503 HV,bending strength of 968 MPa,fracture toughness of 34.83 MPa·m1/2;doping a certain amount of Cr element is beneficial to improve the plasticity of Fe-Al alloy material.