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Superalloy has excellent comprehensive properties and is the preferred material for high performance components of aeroengine. Due to its high yield strength and obvious springback, it is difficult to control the forming precision of superalloy component. Therefore, it is crucial to study the applicability of cyclic constitutive models in the deformation simulation of superalloy foils. Based on the cyclic shearing test, the characterization effects of different cyclic plastic constitutive models on the cyclic plastic deformation response of superalloy were studied. By comparing the results of U-bending test with the simulation results of finite element software, the accuracy of springback prediction of different yield criteria combined with different cyclic plastic constitutive models was analyzed. The results show that Y-U (Yoshida-Uemori) model has the best characterizing effect on the response of cyclic plastic deformation, while A-F (Armstrong-Frederick) model and ANK (the anisotropic nonlinear kinematic) model have close characterizing effect. For the prediction accuracy of springback, the fitting accuracy of Y-U model is higher than that of isotropic model and A-F model. However, the yield criterion has little influence on the prediction accuracy of springback. The prediction deviation of Y-U model based on Hill48 yield criterion and YLD-2000 yield criterion can be controlled within 5%.

Metal matrix composites, reinforced with continuous SiC fiber, offer attractive combinations of high specific strength, specific stiffness and elevated temperature performance and are currently being considered for a range of broad prospective applications. The recent research development on SiC fiber reinforced metal matrix composite was reviewed. The key problems, solutions and application of SiC/Al, SiC/Ti, SiC/Cu, SiC/Ni composites were summarized separately. Finally, the limiting factors in the application of the metal matrix composites were point out:cost issues, interfacial problems, anisotropy of composites and lack of systematic quality estimate.

The deposited billet of a new type powder metallurgy (PM) superalloy FGH4095M for use in turbine disk manufacturing has been fabricated using spray forming technology. The metallurgical quality of the deposited billet was analyzed in terms of density, texture, and grain size. Comparative research was done on the microstructure and mechanical properties between the flat disk preform prepared with hot isostatic pressing (HIP) and the same alloy forgings prepared with HIP followed by isothermal forging (IF). The results show that the density of the spray-formed and nitrogen-atomized deposit billet is above 99% of the theoretical density, indicating a compact structure. The grains are uniform and fine. The billet has weak texture with a random distribution in the spray deposition direction and perpendicular to the direction of deposition. A part of atomizing nitrogen exists in the preform in the form of carbonitride. Nitrogen-induced microporosity causes the density reduction of the preform. Compared with the process of HIP+IF, the superalloy FGH4095M after HIP has better mechanical properties at both room temperature and high temperature. The sizes of the γ′ phase are finer in microstructure of the preform after HIP in comparison with the forgings after HIP+IF. This work shows that SF+HIP is a viable processing route for FGH4095M as a turbine-disk material. [ABSTRACT FROM AUTHOR]