氧化鋁粉表面披覆聚甲基丙烯酸甲酯或聚乙烯醇之研究

Research of Coating Alumina Powder with Polymethylmethacrylate and Polyvinyl Alcohol

陳漢哲(Han-Che Chen)

指導教授 ： 湯華興 ； 嚴孝全

國立臺北科技大學/機電學院/製造科技研究所/碩士(2009年)

摘要

本文之目的為研究將聚甲基丙烯酸甲酯或聚乙烯醇披覆於次微米氧化鋁粉表面，並對完成披覆的粉末作一系列的性質量測。披覆製程使用熱風乾燥。熱風乾燥使用球磨法快速將黏結的披覆氧化鋁粉末細化分離。
由粒徑分析儀量測粒徑分佈，量測顯示經由披覆後得到的粉末，粒徑分佈較無披覆粉末集中。以SEM觀察粉末的表面，無披覆聚甲基丙烯酸甲酯乳膠的氧化鋁粉末表面較光滑，有披覆聚甲基丙烯酸甲酯乳膠表面較粗糙。
由電位分析儀量測披覆前後氧化鋁粉末表面電位值，有披覆的粉末與無披覆的粉末其電位值具有明顯差異。披覆量實驗係將披覆完成的氧化鋁粉以離心機清洗後在爐中燒失，再用精密天秤量測燒失前後的重量。防水性實驗測得披覆聚甲基丙烯酸甲酯乳膠的粉末靜置72小時脫落率平均在10%，而披覆聚乙烯醇在經過加熱180度改質後，在相同條件下脫落率則平均為25%。由三點抗彎實驗中得到披覆聚甲基丙烯酸甲酯乳膠在生坯時的強度為14.71Mpa，經1600度燒結2小時後強度為418.83Mpa，而披覆聚乙烯醇生坯時的強度為13.85Mpa，經1600度燒結2小時後強度為，相較之下披覆聚甲基丙烯酸甲酯乳膠燒結後有較強之抗彎強度。

關鍵字

球磨 ； 披覆 ； 氧化鋁 ； 聚甲基丙烯酸甲酯乳膠 ； 聚乙烯醇

並列摘要

The purpose of this paper is to study the sub-micro alumina powder coated with poly methyl methacrylate or polyvinyl alcohol and to measure the properties of the coated powder. Hot air drying minimized the coated powder by a ball mill; nevertheless, the powder is bigger and need to be minimized by a ball mill.
A particle size analyzer was employed to analysis the particle size distribution. The result revealed that the coated particle has a concentrated particle size distribution. Observing the powder surface by a SEM, the surface of the powder without coating with poly methyl methacrylate was smoother than the surface of the powder coating with poly methyl methacrylate. A Zeta Potential Meter was employed to measure the surface potential of the alumina powder with and without coating. A distinct difference between the alumina powder with and without coating was observed. A coating quantity experiment was done. The coated alumina powder was washed by a centrifuge, and then burned out in a furnace. The weight of the powder before and after coating was measured by a precision scale. The average dewater rate of the powder coated with poly methyl methacrylate in the atmosphere for 72 hours was 10%; on other hand, after heating to 180 °C for powder property changing, the average dewater rate of the powder coated with polyvinyl alcohol was 25%. The flexural strength of the green specimen made of the powder coated with poly methyl methacrylate was 14.71Mpa. 418.83Mpa was achieved when the specimen was sintered at 1600 °C for 2 hours. However, the flexural strength of the green specimen made of the powder coated with polyvinyl alcohol was 13.85Mpa and the flexural strength of the sintered specimen was 325.09Mpa. Obviously, the former had a better flexural strength.

並列關鍵字

Ball Mill ； Coating ； Alumina ； Poly Methyl Methacrylate ； Polyvinyl Alcohol

參考文獻

[21] 蘇紘建，陶瓷雷射燒結快速原型技術之強度提昇及生薄層塊去除研究，碩士論文，國立台北科技大學製造科技研究所，台北，2008。

[11] Emery P. Miller, David D. Taft, "Powder Coating, "1974, Society of Manufacturing Engineers, pp. 161-162.

[12] E.M. Sachs, J. S. Haggerty, M. J. Cima and P. A. Williams, "Three dimensional printing techniques," 1993, United States Patent No. 5204055.

[18] H. H. Tang, "Method for rapid forming of a ceramic work piece," 2001, United States Patent No. 6217816.

[19] H. H. Tang, "Direct laser fusing to form ceramic parts," Rapid Prototyping Journal, vol. 8, no. 5, 2002, pp. 284-289.