This paper discusses the development and implementation of an automatic differentiation based nonlinear reduced order model for unsteady separated flows. The objective of the research presented herein has been to test...
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Cold Gas Dynamic Spraying (CGDS) method was used in order to obtain very dense and good adhesive CoNiCrAlY-coatings deposited onto nickel-based alloy and subsequently remelted by electron beam (EB) up to depth of abou...
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The growth behavior of thermally grown oxide (TGO) on the bond coats of thermal barrier coatings (TBCs) has a significant impact on the TBCs life time. The splashed particles on the thermally sprayed MCrAlY bond coat ...
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Since the discovery of ferromagnetic morphotropic phase boundary(MPB)in 2010,the connotation and extension of MPB have been becoming more and more *** the last dozen years,much experimental work has been done to desig...
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Since the discovery of ferromagnetic morphotropic phase boundary(MPB)in 2010,the connotation and extension of MPB have been becoming more and more *** the last dozen years,much experimental work has been done to design magnetostrictive materials based on the MPB ***,due to the difficulty in direct experimental observations and the complexity of theoretical treatments,the insight into the microstructure property relationships and underlying mechanisms near the ferromagnetic MPB has not been fully ***,we have reviewed our recent computer simulation work about the super-magnetoelastic behavior near the critical region of several typical ***-field modeling and simulation are employed to explore the domain configuration and engineering in single crystals as well as the grain size effect in ***,a general nano-embryonic mechanism for superelasticity is also ***,some future perspectives and challenges are presented to stimulate a deeper consideration of the research paradigm between multiscale modeling and material development.
The non-parabolic isothermal oxidation kinetics of low pressure plasma sprayed MCrAlY bond coat was investigated. To qualitatively explain the abnormal growth phenomenon of thermally grown oxides (TGO), the changes th...
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We present a method for computing the optimal aerodynamic performance of conventional and compound helicopters in trimmed forward flight with a limited set of design variables and control inputs, including conventiona...
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CoNiCrAlY bond coats manufactured by the high-velocity oxygen-fuel spraying (HVOF) and cold gas dynamic spraying (CGDS) deposition technique have been investigated and comparison of phase modification is presented in ...
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ISBN:
(纸本)9788087294628
CoNiCrAlY bond coats manufactured by the high-velocity oxygen-fuel spraying (HVOF) and cold gas dynamic spraying (CGDS) deposition technique have been investigated and comparison of phase modification is presented in the paper. Even though both techniques accelerate powder particles with high kinetic energy, the resulting coatings differ considerably in their microstructures. In the former, high pressure is created by burning gases such as acetylene, propane or kerosene at high pressure and generating high temperature (3500 to 4500 °C) in the gun. This gives high acceleration to powder particles which melt and deposit on substrate layer by layer with splat cool mechanism. On the other hand, large kinetic energy is generated in cold spray by passing carrier gases such as He or N2 through converging-diverging nozzle, with lower gun temperature of around 600 °C. Here the particles are not liquid droplets because of lower temperature and the deposition mechanism is not a splat cooling, but a high impact of solid particles, which results in plastic deformation, making very adherent coating. In this work, CoNiCrAlY powder was deposited on Inconel 718 substrate using HVOF and CGDS deposition process. The bond coats microstructural features were characterized by means of SEM and XRD analyses. The experimental results demonstrated that the CoNiCrAlY bond coats prepared by both HVOF and CGDS technique displayed the lower porosity for CGDS microstructure, and therefore CGDS represents an interesting and promising alternative for their manufacturing.
In situ Ni-TiC nanocomposite was cladded on steel substrate by spark plasma sintering (SPS) method. Reactive powder was prepared by mechanical alloying (MA) of a mixture of Ni, Ti and C elemental powders using a high ...
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ISBN:
(纸本)9781899072408
In situ Ni-TiC nanocomposite was cladded on steel substrate by spark plasma sintering (SPS) method. Reactive powder was prepared by mechanical alloying (MA) of a mixture of Ni, Ti and C elemental powders using a high energy planetary ball mill. Powders and compacted samples were characterized using x-ray diffraction (XRD) and scanning electron microscopy (SEM). Results show that, by the selection of appropriate conditions, a metastable Ni-Ti-C powder could be obtained with the nominal composition Ni(Cr)-32wt.%Ti-8wt.%C. Resultant powder was consolidated on steel substrate by SPS and the microstructure was investigated. XRD results showed the occurrence of an in situ reaction during SPS which led to the formation of TiC nanoparticles in the matrix. SEM revealed an adherent interface of clad layer and the substrate. Microhardness measurement testing showed a hardness of about 1200 VHN and the wear resistant of in situ Ni(Cr)-TiC nanocomposite was excellent according to sliding wear test results.
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