Microstructure and tribological properties of in-situ formed Al₃Zr/A356 composite

Abstract

A1 3 Zr/A356 Composite was prepared by in-situ reaction of K 2 ZrF 6 powder and cast aluminum A356 melt at different temperatures (710°C, 750°C, 770°C, 790°C). The effect of different melting temperature on the morphology of Al 3 Zr particles was studied, and the sliding friction and wear properties of the composites were studied by wear test. It can be seen from the x-ray diffractometer (XRD) that the prepared composite material consists of A1 3 Zr and ɑ-Al, and also has a small part of the aluminum-silicon eutectic phase; SEM analysis shows that the particles of in-situ reinforced phase are fine, With the increase of temperature, the morphology of A1 3 Zr reinforced phase changed from block to needle and strip, and the particle distribution of the reinforced phase was uniform and well dispersed in the matrix at 750°C. TEM experiments show that the reinforced phase exists at 750°C and has a good combination with the matrix, which plays a very good role in particle reinforcement Friction and wear experiments show that the different preparation temperature results in different phase morphology. The reinforced phase particles existing on the surface of composites at 710°C and 750°C bear most of the friction, so the friction coefficient of the composites is larger at these preparation temperature, and the main wear modes are oxidation wear and abrasive wear. The friction coefficient of the composites prepared at 770°C and 790°C is small, and the wear modes are mainly delamination wear and oxidation wear. When the preparation temperature is 750°C, the wear resistance of the composites is the best.

Preparation of in-situ ZrB2/A356 composites and high-temperature tribological studies

“…Using a laser confocal microscope(LEXTOLS4000) to observe and measure the abrasion marks of the composite material at various temperatures, different abrasion cross-sections at different locations were selected, and three abrasion marks were selected at each location to measure the average cross-sectional area of the abrasion marks. The wear rate was obtained using the equation = K , CS FL C is the circumference, S is the cross-sectional area, F is the load, and L is the length of the abrasion marks [27,28]. The calculated wear rate is shown in figure 12 (the wear rate could not be calculated because the abrasion marks were in the form of a bump at 300 °C).…”

“…= C is the circumference, S is the cross-sectional area, F is the load, and L is the length of the abrasion marks [27,28]. The calculated wear rate is shown in figure 12 (the wear rate could not be calculated because the abrasion marks were in the form of a bump at 300 °C).…”

Microstructure and tribological behavior of in situ ZrB2/A356 composites prepared under magnetic field

“…In recent years, more and more attention has been paid to in-situ aluminum matrix composites due to their clear interface between matrix and reinforcement, high bonding strength and good interface integrity [1][2][3][4][5][6][7][8][9]. Due to its unique composite properties, in-situ aluminum matrix composites have a wide range of applications in the fields of aircraft shell, landing gear pillar and turbine engine components.…”