کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1581602 | 1514863 | 2008 | 8 صفحه PDF | دانلود رایگان |
Proper control of composition gradients in components processed by liquid-phase sintering requires the control of the migration of the liquid phase during sintering. A model considering isotropic interface energies has been developed for expressing the variation of the solid–liquid interface area with liquid volume fraction during the final stage of liquid-phase sintering (i.e. when residual porosity has disappeared). The model allows the computation of the driving forces for shape accommodation as a function of the dihedral angle ψ, liquid volume fraction, u, particle volume, Vp, and average particle coordination, nc. It particularly enlightens the coupling between the effects of ψ and of nc. The model allows a new insight into the control of microstructural evolution during liquid-phase sintering of assemblies of dual-phase materials with different average particle size. Taking ψ = 0° for the WC–Co system, the model was found to predict with a good accuracy the distribution of Co at equilibrium in assemblies made by heat-treating at 1400 °C under protective atmosphere stacks of cylinders of WC–Co cermets differing in mean WC particle size and cobalt content.
Journal: Materials Science and Engineering: A - Volume 495, Issues 1–2, 15 November 2008, Pages 236–243