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Due to its negligible solubility, it is difficult to obtain a W-30Cu composite with a homogenous microstructure. However, with a selected W skeleton, a homogeneous phase distribution was achieved for a W-30Cu composite in the present study. By detailed characterization of the mechanical performance and microstructure of the W-30Cu composite, as well as the stress distribution state under a loading condition, the effects of microstructure homogeneity on the mechanical properties and failure mechanisms are identified. The mechanisms by which the ductility and strength depend on microstructure homogeneity contain the effects on plastic deformation and stress coordination of the Cu phase network. The dominant factors for the high ductility and strength of W-30Cu composites are proposed.

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In the present study the supersonic flow over rigid parachute models is studied by numerically solving the three-dimensional compressible Navier-Stokes equations at a free stream Mach number of 2. The parachute system employed here consists of a capsule and a canopy. Two models are considered: model A and model B. The former is the same model as the experiment, where the canopy is connected with the capsule by a rod, and the whole system is supported by another rod, while the latter does not have these rods. The objective of the present study is to examine the flow field produced by these models, and analyze the effects of aerodynamic interaction such as shock/shock and wake/shock interactions on it. The numerical results show good agreement with the experimental data in the case of model A. In addition, it is found that the difference of flow features between models A and B is rather small. The unsteady flow pulsation phenomenon observed in this study can be demonstrated using three processes; the bow shock formed ahead of the capsule periodically inflates and laterally expands, which is caused by upstream propagation and lateral expansion of the complicated wake/rear shock and fore shock/rear shock interaction systems.

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