An approach named direct reaction synthesis (DRS) has been developed to fabricate particulate composites with an extremely fine reinforcement size. ID situ Al matrix composites were fabri-cated by DRS. Extensive analy...An approach named direct reaction synthesis (DRS) has been developed to fabricate particulate composites with an extremely fine reinforcement size. ID situ Al matrix composites were fabri-cated by DRS. Extensive analysis of the composites microstructure using SEM and TEM identify that the reinforcement formed during the DRS process is Ti carbide (TiC) particle, generally less than 1.0 μm. The reacted, semisolid extruded samples exhibit a homogeneous distribution of fine TiC particles in Al-Cu matrix, Mechanical property evaluation of the composites has revealed a very high tensile strength relative to the matrix alloy. Fractographic analysis indicates ductile failure although the ductility and strength are limited by the presence of coarse titanium aluminides (Al3Ti).展开更多
In this paper, the phenomena of spirals are numerically presented by MmB scheme [1] for initial value problems of 2-D gas dynamics (gamma = 1.4), which include 2-D Riemann problems and continuous initial value problem...In this paper, the phenomena of spirals are numerically presented by MmB scheme [1] for initial value problems of 2-D gas dynamics (gamma = 1.4), which include 2-D Riemann problems and continuous initial value problems. The numerical results are well coincide with on the exact solution in [2] and the conjectures on solution structure in [3] for 2-D isentropic and adiabatic flows. In isentropic flow, for high speed rotation (v(0)/c(0) > root 2), there is a region of vacuum at the origin and for low speed rotation (v(0)/c(0) < root 2), there is no vacuum, and for adiabatic flow, the structure of spirals is also discussed.展开更多
文摘An approach named direct reaction synthesis (DRS) has been developed to fabricate particulate composites with an extremely fine reinforcement size. ID situ Al matrix composites were fabri-cated by DRS. Extensive analysis of the composites microstructure using SEM and TEM identify that the reinforcement formed during the DRS process is Ti carbide (TiC) particle, generally less than 1.0 μm. The reacted, semisolid extruded samples exhibit a homogeneous distribution of fine TiC particles in Al-Cu matrix, Mechanical property evaluation of the composites has revealed a very high tensile strength relative to the matrix alloy. Fractographic analysis indicates ductile failure although the ductility and strength are limited by the presence of coarse titanium aluminides (Al3Ti).
文摘In this paper, the phenomena of spirals are numerically presented by MmB scheme [1] for initial value problems of 2-D gas dynamics (gamma = 1.4), which include 2-D Riemann problems and continuous initial value problems. The numerical results are well coincide with on the exact solution in [2] and the conjectures on solution structure in [3] for 2-D isentropic and adiabatic flows. In isentropic flow, for high speed rotation (v(0)/c(0) > root 2), there is a region of vacuum at the origin and for low speed rotation (v(0)/c(0) < root 2), there is no vacuum, and for adiabatic flow, the structure of spirals is also discussed.
