使用不同混煉機構製備均勻氧化鋯射出胚料之研究

Study on the Preparation of Homogenous Zirconia Feedstocks by Various Kneading Mechanisms

吳榮源(R. Y. Wu) ； 韋文誠(W. J. Wei)

《材料科學與工程》 36卷4期 (2004/12) Pp. 236-247

https://doi.org/10.6409/JMSE.200412.0236

摘要

本研究使用三種氧化釔添加之氧化鋯粉，針對不同混煉機型，例如Z-型混煉機、雙滾筒混煉機或剪力捏練儀，製備出高均勻性之氧化鋯胚料，並利用適當的參數分析胚料分散的特性。實驗首先利用具有高分佈機構之Z-型混煉機製備出分散指數(D(下標 s))為81%的氧化鋯胚料，再使用高分散機構設備，如雙滾筒混煉機或剪力捏練儀，混煉胚料至D(下標 x)高於98%條件，再進行造粒。將此5mm射料進行射出、脫脂與燒結。燒結試片尺寸之最小標準差百分比皆小於0.1%。內部沒有粉體聚結之燒結體具有之破壞強度(σ=790MPa)遠優於其他含有各種粉體聚結燒結體之破壞強度。破壞源觀察結果顯示，小於20μm聚結容易殘留在燒結體中，影響氧化錯之破壞強度，而且此類聚結為氧化鋯之主要破壞源，其型態與造粒粉體型態相似。

關鍵字

氧化鋯 ； 胚料 ； 混煉機 ； 剪應力 ； 尺寸變化 ； 強度 ； 破壞源

並列摘要

Highly homogenous feedstocks were prepared from three yttria-doped ZrO2 powders by different kneading equipments, Z-blade kneader twin-roller mixer, or torque kneader, and characterized by appropriate parameter to reveal the dispersive properties of the feedstocks The Z-blade kneader with good distribution mixing as firstly used to get one zirconia feedstock of dispersive index (D(subscript s)) 0.81. The feedstock was then kneaded again to achieve nearly homogenous condition (D(subscript s)＞98%) by twin-roller mixer or torque kneader. The zirconia feedstock was granulated to uniform 5 mm pellets by single screw extruder. Test bar specimens were injection molded, thermal debinded, and sintered. The best normal standard deviation of the sintered specimens was less than 0.1% in longitudinal dimension. The fracture strength of the sintered parts (E2-KRS) without powder agglomerate (σ=790MPa) was highest among the others, which prepared from different powders with various agglomeration and kneading conditions. The agglomerates in sizes ＜20μm were identified in the sintering parts as the most significant fracture origin, which was similar to the residual granulated powder in the feedstocks.

並列關鍵字

zirconia feedstock ； Z-blade kneader ； twin roller kneader ； torque rheometer ； shear stress ； dimensional variation ； fracture origin