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Effect of surface modifier on the rheological properties of Mg2TiO4 microwave ceramics injection molding feedstock |
SHI Yuan, LIU Shaojun |
Powder Metallurgy Research Institute, Central South University, Changsha 410000, China |
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Abstract Mg2TiO4 powders were modified by surfactants of stearic acid (SA), oleic acid (OA), 3-glycidyloxy- propyltrimethoxysilane (KH560) and 3-methacrylate-propyltrimethoxysilane (KH570). The effects of surfactants on the particle size distribution of Mg2TiO4 powders and its mechanism were characterized by infrared analysis and particle size measurement. The Mg2TiO4 powders before and after modification were used to prepared feedstocks with 44% solid load (volunm fraction). The effects of surfactants on the rheological properties, theoretical maximum loading capacity φmax, activation energy and yield stress of feedstock were studied. The results show that the surfactants are chemisorbed on Mg2TiO4 powder, which effectively reduce powder agglomeration. The OA can significantly reduce the viscosity and rheological activation energy of feedstock. The viscosity decreases from 39.55 Pa·s to 5.43 Pa·s (100 s-1); the activation energy decreases from 62 kJ/mol to 38 kJ/mol (100 s-1). The lowest yield stress of 12 Pa is obtained at 170 ℃ (1 832 kPa before modification). The maximum solid loading modified with KH560 is 135%.
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Received: 16 March 2021
Published: 10 November 2021
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