Al2O3-SiO2(sf)/AZ91D composite was fabricated by squeezing infiltration using preform made of crystallized aluminum silicate short fibers as reinforcement and aluminum phosphate as binder. The interfacial reaction pro...Al2O3-SiO2(sf)/AZ91D composite was fabricated by squeezing infiltration using preform made of crystallized aluminum silicate short fibers as reinforcement and aluminum phosphate as binder. The interfacial reaction products were investigated by optical microscopy, X-ray diffractometry, scanning electron microscopy, and the thermodynamics was discussed. It is shown that alumina silicate fibers are ideal candidates for the reinforcement of the Mg alloy matrix composites, and the perfect strong interfaces were formed by the chemical reaction between Mg in the magnesium alloy matrix and aluminum phosphate binder through generation of MgO particles. In addition, brittle Mg2Si phase was precipitated at the interface through the reaction between amorphous SiO2 and Mg in the magnesium alloy matrix, which affects the mechanical property of the composite.展开更多
Aluminum(Al) 2024 matrix composites reinforced with alumina short fibers(Al_2O_(3sf)) and silicon carbide particles(SiC_p) as wear-resistant materials were prepared by pressure infiltration in this study. Further, the...Aluminum(Al) 2024 matrix composites reinforced with alumina short fibers(Al_2O_(3sf)) and silicon carbide particles(SiC_p) as wear-resistant materials were prepared by pressure infiltration in this study. Further, the effect of Al_2O_(3sf) on the friction and wear properties of the as-synthesized composites was systematically investigated, and the relationship between volume fraction and wear mechanism was discussed. The results showed that the addition of Al_2O_(3sf), characterized by the ratio of Al_2O_(3sf) to SiC_p, significantly affected the properties of the composites and resulted in changes in wear mechanisms. When the volume ratio of Al_2O_(3sf) to SiC_p was increased from 0 to 1, the rate of wear mass loss(K_m) and coefficients of friction(COFs) of the composites decreased, and the wear mechanisms were abrasive wear and furrow wear. When the volume ratio was increased from 1 to 3, the COF decreased continuously; however, the K_m increased rapidly and the wear mechanism became adhesive wear.展开更多
Effects of the volume fraction and the size of crystallized alumina silicate short fibers as well as heat treatment processes on micro-yield strength(MYS) of Al2O3-SiO2(sf)/Al-Si metal matrix composite(MMC) that was f...Effects of the volume fraction and the size of crystallized alumina silicate short fibers as well as heat treatment processes on micro-yield strength(MYS) of Al2O3-SiO2(sf)/Al-Si metal matrix composite(MMC) that was fabricated by squeezing cast, were investigated by using continuous loading method on an Instron 5569 tester with a special extensometer with an accuracy of 10?7. The results show that MYS of MMC decreases with the increase of volume fraction and length of the alumina silicate short fibers in the metal matrix composite, respectively. MYS of quenched Al2O3-SiO2(sf)/Al-Si MMC is the lowest, MYS of the MMC through peak-aging treatment is higher than that through other heat treatment methods. And before the peak-aging, MYS of MMC aging treated gradually increases with the increase of the aging time. Aging treatment after solution treatment is a preferred way that enhances micro and macro-yield strength of Al2O3-SiO2(sf)/Al-Si MMC.展开更多
基金Project(305-E5040440) support by the Natural Science Foundation of South China University of Technology
文摘Al2O3-SiO2(sf)/AZ91D composite was fabricated by squeezing infiltration using preform made of crystallized aluminum silicate short fibers as reinforcement and aluminum phosphate as binder. The interfacial reaction products were investigated by optical microscopy, X-ray diffractometry, scanning electron microscopy, and the thermodynamics was discussed. It is shown that alumina silicate fibers are ideal candidates for the reinforcement of the Mg alloy matrix composites, and the perfect strong interfaces were formed by the chemical reaction between Mg in the magnesium alloy matrix and aluminum phosphate binder through generation of MgO particles. In addition, brittle Mg2Si phase was precipitated at the interface through the reaction between amorphous SiO2 and Mg in the magnesium alloy matrix, which affects the mechanical property of the composite.
基金financially supported by the National Natural Science Foundation of China (No. 51374028)
文摘Aluminum(Al) 2024 matrix composites reinforced with alumina short fibers(Al_2O_(3sf)) and silicon carbide particles(SiC_p) as wear-resistant materials were prepared by pressure infiltration in this study. Further, the effect of Al_2O_(3sf) on the friction and wear properties of the as-synthesized composites was systematically investigated, and the relationship between volume fraction and wear mechanism was discussed. The results showed that the addition of Al_2O_(3sf), characterized by the ratio of Al_2O_(3sf) to SiC_p, significantly affected the properties of the composites and resulted in changes in wear mechanisms. When the volume ratio of Al_2O_(3sf) to SiC_p was increased from 0 to 1, the rate of wear mass loss(K_m) and coefficients of friction(COFs) of the composites decreased, and the wear mechanisms were abrasive wear and furrow wear. When the volume ratio was increased from 1 to 3, the COF decreased continuously; however, the K_m increased rapidly and the wear mechanism became adhesive wear.
基金Project(19972021)supported by the National Natural Science Foundation of China
文摘Effects of the volume fraction and the size of crystallized alumina silicate short fibers as well as heat treatment processes on micro-yield strength(MYS) of Al2O3-SiO2(sf)/Al-Si metal matrix composite(MMC) that was fabricated by squeezing cast, were investigated by using continuous loading method on an Instron 5569 tester with a special extensometer with an accuracy of 10?7. The results show that MYS of MMC decreases with the increase of volume fraction and length of the alumina silicate short fibers in the metal matrix composite, respectively. MYS of quenched Al2O3-SiO2(sf)/Al-Si MMC is the lowest, MYS of the MMC through peak-aging treatment is higher than that through other heat treatment methods. And before the peak-aging, MYS of MMC aging treated gradually increases with the increase of the aging time. Aging treatment after solution treatment is a preferred way that enhances micro and macro-yield strength of Al2O3-SiO2(sf)/Al-Si MMC.
