Aluminum matrix composites reinforced by in situ Al2O3 and Al3Zr particles are fabricated from A356-Zr(CO3)2 system via magnetochemistry reaction,and the morphologies,sizes and distributions of the in situ particles a...Aluminum matrix composites reinforced by in situ Al2O3 and Al3Zr particles are fabricated from A356-Zr(CO3)2 system via magnetochemistry reaction,and the morphologies,sizes and distributions of the in situ particles as well as the microstructures,mechanical mechanisms of the composites are investigated by XRD,SEM,TEM and in situ tensile tests.The results indicate that with the pulsed magnetic field assistance,the morphologies of the in situ particles are mainly with ball-shape,the sizes are in nanometer scale and the distributions in the matrix are uniform.The interfaces between the in situ particles and the aluminum matrix are net and no interfacial outgrowth is observed.These are due to the strong vibration induced by the applied magnetic field in the aluminum melt,which in turn,accelerates the melt reactions.The effects of the magnetic field on the above contributions are discussed in detail.展开更多
SiC/7075 aluminum matrix composites were prepared by a liquid stirring method.The role of Ti facilitating the preparation of SiC/7075 aluminum matrix were studied by means of direct-reading spectrometer,scanning elect...SiC/7075 aluminum matrix composites were prepared by a liquid stirring method.The role of Ti facilitating the preparation of SiC/7075 aluminum matrix were studied by means of direct-reading spectrometer,scanning electron microscope,energy dispersive spectrometer,X-ray diffraction and the sessile drop method.The results show that the SiC content in the SiC/7075 composite increases with an increase of Ti addition.The addition of Ti can significantly improve the wettability of SiC/Al system,there is a critical value of above 0.5%of Ti content in improving the wettability of the Al/SiC system at 1173K.The temperature of the"non wetting-wetting"transition for the(Al-2Ti)/SiC system is about 1123K,the contact angle decreases to 88°at 200 seconds and reaches a stable contact angle of 28°at 2100 seconds.展开更多
Nanoparticles and microparticles reinforced Al matrix composites were fabricated by spark plasma sintering, and the microstructure and tribological properties were investigated systemically. The nano-Al2O3 particle an...Nanoparticles and microparticles reinforced Al matrix composites were fabricated by spark plasma sintering, and the microstructure and tribological properties were investigated systemically. The nano-Al2O3 particle and micro-Al2O3 particle uniformly dispersed in Al matrix composites. The introduction of nanoparticles is beneficial to the decrease of friction coefficient and wear rate, while microparticles are responsible to the high friction coefficient, resulting in the abrasive wear. With the introduction of both nanoparticles and microparticles, their synergic effect will lead to the variation of tribological behavior.展开更多
基金Project(2007AA03Z548) supported by High-Tech Research and Development Program of ChinaProject(50971066) supported by the National Natural Science Foundation of ChinaProject(1283000349) supported by the Jiangsu University Research Fund for Advanced Scholars,China
文摘Aluminum matrix composites reinforced by in situ Al2O3 and Al3Zr particles are fabricated from A356-Zr(CO3)2 system via magnetochemistry reaction,and the morphologies,sizes and distributions of the in situ particles as well as the microstructures,mechanical mechanisms of the composites are investigated by XRD,SEM,TEM and in situ tensile tests.The results indicate that with the pulsed magnetic field assistance,the morphologies of the in situ particles are mainly with ball-shape,the sizes are in nanometer scale and the distributions in the matrix are uniform.The interfaces between the in situ particles and the aluminum matrix are net and no interfacial outgrowth is observed.These are due to the strong vibration induced by the applied magnetic field in the aluminum melt,which in turn,accelerates the melt reactions.The effects of the magnetic field on the above contributions are discussed in detail.
基金the Natural Science Foundation of Shanxi Province,China(No.201801D121108)。
文摘SiC/7075 aluminum matrix composites were prepared by a liquid stirring method.The role of Ti facilitating the preparation of SiC/7075 aluminum matrix were studied by means of direct-reading spectrometer,scanning electron microscope,energy dispersive spectrometer,X-ray diffraction and the sessile drop method.The results show that the SiC content in the SiC/7075 composite increases with an increase of Ti addition.The addition of Ti can significantly improve the wettability of SiC/Al system,there is a critical value of above 0.5%of Ti content in improving the wettability of the Al/SiC system at 1173K.The temperature of the"non wetting-wetting"transition for the(Al-2Ti)/SiC system is about 1123K,the contact angle decreases to 88°at 200 seconds and reaches a stable contact angle of 28°at 2100 seconds.
基金Funded by the National Key R&D Program of China(No.2017YFB1103500)National Science and Technology Major Project(No.2017-VI-0007-0077)the National Natural Science Foundation of China(Nos.51632007,51672218)
文摘Nanoparticles and microparticles reinforced Al matrix composites were fabricated by spark plasma sintering, and the microstructure and tribological properties were investigated systemically. The nano-Al2O3 particle and micro-Al2O3 particle uniformly dispersed in Al matrix composites. The introduction of nanoparticles is beneficial to the decrease of friction coefficient and wear rate, while microparticles are responsible to the high friction coefficient, resulting in the abrasive wear. With the introduction of both nanoparticles and microparticles, their synergic effect will lead to the variation of tribological behavior.
