| Continuous rheo-extrusion technology has a significant effect on the grain fined and breakage of coarse iron rich phase in the Al-Fe alloy,which improve the mechanical property of the Al-Fe alloy.In this paper,study on the evolution of microstructure and mechanical property of the Al-Fe alloy by means of hardness and tensile test,as well as X-ray diffraction(XRD),electron backscattered diffraction(EBSD),scanning electron microscope(SEM)and transmission electron microscope(TEM),to explore its thermal stability.The main findings are as follows:(1)With the increase of the extrusion pass,the Fe-rich phase of Al-Fe alloy was broken to a certain extent and the Fe-rich phase size was reduced,indicating that the continuous rheo-extrusion has a significant effect on the crushing of coarse Fe-rich phase,Which helps to reduce the fragmentation of coarse Fe-rich matrix;with the increase of Fe content,the number of Fe-rich phase increases.(2)After two times of continuous rheological extrusion,the grain morphology of Al-l.5Fe alloy is equiaxed,and the proportion of large angle grain boundaries is 55.06%.After two passes of continuous rheo-extrusion,the Al-1.5Fe alloy still has good work-hardening ability,indicating that the Al-1.5Fe alloy has a certain degree of dynamic recrystallization.(3)The strength and hardness of Al-Fe alloy decrease with the increase of extrusion pass,and the elongation increases with the increase of extrusion pass.Al-Fe alloy has a certain degree of dynamic recrystallization during continuous rheo-extrusion,which is the main reason for the decrease of strength and hardness.(4)When the annealing temperature is in the range of 150℃-200℃,the grain size does not grow obviously,and the low angle grain boundaries have a larger proportion and the microstructure is recovered.After annealing at 250℃,the proportion of large angle grain boundaries in the alloy increased significantly,indicating that recrystallization of the alloy began to occur.The grain size increases obviously after annealing at 350℃,and the proportion of the large angle grain boundaries is 83.33%.This indicates that the alloy has completely recrystallized after annealing at 350℃,and the growth of grain occurs in some areas.(5)Al-1.5Fe alloy began significant work hardening when Al-15Fe alloy annealed at 250℃.With the increase of annealing temperature,the work hardening ability of Al-1.5Fe alloy increased remarkably.The strength and hardness of Al-1.5Fe alloy decrease with the increase of annealing temperature.The plasticity increases with the increase of annealing temperature. |
