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Full-Text Articles in Engineering
Spontaneous Jumping, Bouncing And Trampolining Of Hydrogel Drops On A Heated Plate, Jonathan T. Pham, Maxime Paven, Sanghyuk Wooh, Tadashi Kajiya, Hans-Jürgen Butt, Doris Vollmer
Spontaneous Jumping, Bouncing And Trampolining Of Hydrogel Drops On A Heated Plate, Jonathan T. Pham, Maxime Paven, Sanghyuk Wooh, Tadashi Kajiya, Hans-Jürgen Butt, Doris Vollmer
Chemical and Materials Engineering Faculty Publications
The contact between liquid drops and hot solid surfaces is of practical importance for industrial processes, such as thermal spraying and spray cooling. The contact and bouncing of solid spheres is also an important event encountered in ball milling, powder processing, and everyday activities, such as ball sports. Using high speed video microscopy, we demonstrate that hydrogel drops, initially at rest on a surface, spontaneously jump upon rapid heating and continue to bounce with increasing amplitudes. Jumping is governed by the surface wettability, surface temperature, hydrogel elasticity, and adhesion. A combination of low-adhesion impact behavior and fast water vapor formation …
Preparation And Microstructure Of Machinable Al2O3/Mica Composite By Ball Milling And Hot-Press Sintering, Qingbo Tian, Deyu Kong, Tongguang Zhai
Preparation And Microstructure Of Machinable Al2O3/Mica Composite By Ball Milling And Hot-Press Sintering, Qingbo Tian, Deyu Kong, Tongguang Zhai
Chemical and Materials Engineering Faculty Publications
A machinable α-Al2O3/mica composite was prepared by hot-press sintering. In this experiment, a mica-contained glass ceramic in the MgO-Al2O3-SiO2-F glassy system was employed and the base glass powders were obtained by traditional melting-quenched method. Then, α-Al2O3 milling swarf was introduced by medium α-alumina milling ball to the glass powders. The test results indicate that the composites consist of mica crystal and mullite crystal, which are precipitated in the base glass. The α-Al2O3 shows an irregular polygon, which is inlayed in the base material. With …