3 research outputs found
袛袠肖袪袗袣笑袠携 袙袨袥袧蝎 H10 袧袗 小孝蝎袣袝 袪袝袚校袥携袪袧袨袚袨 袠 袧袝袪袝袚校袥携袪袧袨袚袨 袙袨袥袧袨袙袨袛袨袙 小 袛袠协袥袝袣孝袪袠效袝小袣袨袡 袩袥袗小孝袠袧袨袡 袣袨袧袝效袧袨袡 袛袥袠袧蝎
On the basis of the projection method the rigorous solution of the basic wave 袧10 diffraction problem on a joint of a regular and non-regular waveguides with a dielectric plate placed parallel to narrow impedance walls is presented. The problem is solved by the method of partial areas. For each of three dedicated areas subject to boundary conditions on the waveguide walls solution of Helmholz equation is put down in the form of cross-section eigenfunction. For a non-regular area including impedance walls and a dielectric plate the solution of Helmholz equation leads to a dispersion equation from which the propagation constants in the area under investigation is determined. Meanwhile, the influence of the impedance walls is considered by means of the Leontovich boundary conditions.袗薪芯褌邪褑褨
Fabrication of metal matrix composites of
Fine fibrous titanium carbide (TiC) was processed through the self-propagating high-temperature synthesis (SHS) method and employed to fabricate aluminum matrix composites. Two consol-idation methods were investigated: (1) combustion synthesis of TiC fiber/Al composites directly using titanium powders and carbon fibers ignited simultaneously with varying amounts of the matrix metal powder and (2) combustion synthesis of TiC using titanium powders and carbon fibers followed by consolidation into different amounts of the metal matrix powder, Al, via hot isostatic pressing (HIP). In the former method, when the amount of the Al in the matrix was increased, the maximum temperature obtained by the combustion reaction decreased and the propagation of the synthesis reactions became difficult to maintain. Preheating was required for the mixture of reactants with more than approximately 5 mole pct aluminum matrix powders in order to ignite and maintain the propagation rate. Microstructural analysis of the products from the Al/C/Ti reaction without preheating shows that small amounts of an aluminum carbide phase (AI4C3) are present. In the second method, following separation of the individual fibers in the TiC product, dense composites containing the SHS products were obtained by HIP of a mixture of the TiC fibers and Al powders. No ternary phase was formed during this procedure. 漏 1992 The Minerals, Metals and Materials Society, and ASM International