In recent decades, fast-hardening aluminum-based alloys (BTS) have attracted considerable attention due to their potential in various fields of technology. Rapid solidification of the melt makes it possible to obtain a microcrystalline or amorphous structure, which leads to improved mechanical properties compared to traditional alloys. Alloying with transition metals such as titanium and iron further improves the strength and heat resistance of aluminum alloys. Extrusion is an effective method of consolidating powder materials, allowing you to get compact workpieces with high density and the required shape.
In this paper, the mechanical properties of fast-hardening alloys based on the Al-Ti-Fe, Al-Cu-Fe, and Al-Fe-Cu-Ti systems are studied. Alloy powders were obtained by sputtering the melt with argon. The chemical composition of the alloys was monitored by X-ray fluorescence analysis. The morphology of the powders was studied using scanning electron microscopy (SEM). The powders were consolidated by hot extrusion at a temperature of 400°C and a degree of deformation equal to 10. The resulting bars were subjected to mechanical tests for tension, compression and hardness. The microstructure of the extruded samples was studied by optical and electron microscopy. The phase composition was determined by X-ray diffraction (XRD).
The results of the study showed that the microstructure of extruded alloys is characterized by a fine-grained structure with a uniform distribution of alloying elements. In Al-Ti-Fe alloys, the formation of intermetallic phases Al3Ti and AlFe was observed, which contributed to dispersion hardening. Al2Cu and AlFe phases were formed in Al-Cu-Fe alloys, and Al3Ti, AlFe, and Al2Cu were formed in Al-Fe-Cu-Ti alloys. The tensile strength of extruded Al-Ti-Fe alloys reached 600 MPa, and the yield strength was 500 MPa. For Al-Cu-Fe alloys, the corresponding values were 550 MPa and 450 MPa, and for Al-Fe-Cu-Ti alloys, 580 MPa and 480 MPa. The Vickers hardness for all the alloys studied was in the range of 150-180 HV. Microstructural analysis has shown that during the extrusion process, grains are crushed and phases are redistributed, which leads to an increase in mechanical properties. A correlation was found between the phase composition and mechanical properties of the alloys.
The method of hot extrusion of atomized powders is an effective method for producing high-strength fast-hardening alloys based on Al-Ti-Fe, Al-Cu-Fe and Al-Fe-Cu-Ti. Alloying with titanium and iron contributes to the formation of dispersed intermetallic phases, which increase the strength and hardness of alloys. Varying the chemical composition allows you to adjust the phase composition and, accordingly, the mechanical properties of the extruded materials. The studied alloys have promising mechanical characteristics for use in the aviation and automotive industries. Further research will focus on optimizing the extrusion and heat treatment modes to achieve maximum mechanical properties.
Author: J.Q. Guo, N.S. Kazama
Institute: Sendai Institute of Materials Science and Technology, YKK Corporation, 38 Akaishi, Miyagi 98133, Japan