SiC_(p)/AZ91 composites were prepared by vacuum pressure infiltration.The microstructure,mechanical properties and wear resistance of composite were studied.Results indicated that SiC particles were uniformly distribu...SiC_(p)/AZ91 composites were prepared by vacuum pressure infiltration.The microstructure,mechanical properties and wear resistance of composite were studied.Results indicated that SiC particles were uniformly distributed in the metal matrix and had a good interface bonding with the metal matrix.Mg_(17)Al_(12) preferably precipitated near the SiC particles,and high-density dislocations were induced by the mismatch of the coefficient of thermal expansion(CTE)between the SiC particle and the AZ91 matrix,thereby accelerating the aging precipitation of the matrix.Compared with AZ91 alloy,the addition of SiC particles improves the hardness and compressive strength of the composite,which is mainly due to the load transfer strengthening and grain refinement strengthening mechanisms.Furthermore,a stable support surface-protecting matrix formed during the wear process because of the excellent wear resistance of SiC.展开更多
Tons of solid particles, like carbon, beryllium and tungsten with diameters of several to several hundreds microns, would be generated as dusts in vacuum vessel during operation of ITER, In accident scenarios, e.g., l...Tons of solid particles, like carbon, beryllium and tungsten with diameters of several to several hundreds microns, would be generated as dusts in vacuum vessel during operation of ITER, In accident scenarios, e.g., loss of vacuum accident, the potentially combustible dust particles can be suspended by the air ingress and entrained into the whole vessel, and impose a risk of dust explosions to the whole facility. Therefore, the mechanism of particle resuspension was investigated theoretically. A force balance approach and numerical fittings have been utilized to develop a semi-empirical particle resuspension model based on a group of particle resuspension experimental data. The model has been applied into a three-dimensional computational fluid dynamics code, GASFLOW. The model validation has been done by comparison of the numerical predictions about particle resuspension rates in given incoming flows against the corresponding experimental data. The comparisons have proved the validity of the developed model.展开更多
基金financial supports from the National Natural Science Foundation of China(Nos.U1810208,51575230)the Science and Technology Development Program of Jilin Province,China(No.20190302059GX)。
文摘SiC_(p)/AZ91 composites were prepared by vacuum pressure infiltration.The microstructure,mechanical properties and wear resistance of composite were studied.Results indicated that SiC particles were uniformly distributed in the metal matrix and had a good interface bonding with the metal matrix.Mg_(17)Al_(12) preferably precipitated near the SiC particles,and high-density dislocations were induced by the mismatch of the coefficient of thermal expansion(CTE)between the SiC particle and the AZ91 matrix,thereby accelerating the aging precipitation of the matrix.Compared with AZ91 alloy,the addition of SiC particles improves the hardness and compressive strength of the composite,which is mainly due to the load transfer strengthening and grain refinement strengthening mechanisms.Furthermore,a stable support surface-protecting matrix formed during the wear process because of the excellent wear resistance of SiC.
文摘Tons of solid particles, like carbon, beryllium and tungsten with diameters of several to several hundreds microns, would be generated as dusts in vacuum vessel during operation of ITER, In accident scenarios, e.g., loss of vacuum accident, the potentially combustible dust particles can be suspended by the air ingress and entrained into the whole vessel, and impose a risk of dust explosions to the whole facility. Therefore, the mechanism of particle resuspension was investigated theoretically. A force balance approach and numerical fittings have been utilized to develop a semi-empirical particle resuspension model based on a group of particle resuspension experimental data. The model has been applied into a three-dimensional computational fluid dynamics code, GASFLOW. The model validation has been done by comparison of the numerical predictions about particle resuspension rates in given incoming flows against the corresponding experimental data. The comparisons have proved the validity of the developed model.
