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題 名 | 粉末含量對射料流體行為的影響=Effect of Ceramic Powder on Injection Molding Process |
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作 者 | 康振雄; | 書刊名 | 修平學報 |
卷 期 | 1 2000.09[民89.09] |
頁 次 | 頁27-44 |
分類號 | 440.33 |
關鍵詞 | 陶瓷射出成型; 氧化鋁; 粉體含量; 流變; Ceramic injection molding alumina; Solid content; Rheology; |
語 文 | 中文(Chinese) |
中文摘要 | 射出成型所要求的是射出料在加熱後能有足夠的流動性,以免在充填模穴過程中 產生缺陷;過高的粉末含量往往會使射料的黏度增大,造成射出困難;但是對於陶瓷的燒結 而言,射出料中陶瓷粉末所佔比率越高,可以縮短物質擴散的路徑而得到較緻密的燒結體, 亦可以減少收縮率而提高尺寸的精確度,因此有相當多的研究嘗試增加射出料的固體含量以 達到上述目的。 本研究探討不同粉末含量之氧化鋁射料之流變行為,以瞭解射料在剪變速率變化區間黏度的 變化及射料黏度受溫度、粉末含量之影響。研究結果顯示較高的粉末含量、較低的溫度及剪 應變速率均會增大射料的黏度; 各種射料之活化能及 dlog η /dT 值均呈兩段分佈,低溫 時射料的活化能及對溫度的敏感度均較高溫時大, 這可能是因為高密度聚乙烯( m.p.130-140 ℃)與低密度聚乙烯( m.p.100-110 ℃)熔解所造成之效應; 由此可決定各 種射料之射出溫度。 |
英文摘要 | In injection molding process the metal or ceramic powder is blended with organic vehicles (often called binders) such as wax or polymer. A primary requirement for injection molding is that the compound must have an adequate fluidity for molding. High volume fraction of ceramic powder will increase the viscosity of ceramic-binder compound making processing more difficult. However, there have been studies on processes to increase the powder volume fraction of the compounds to achieve high green density and reduce shrinkage during sintering. In the present study, alumina feedstocks will be prepared with different solid contents and rheometer will be applied to evaluate the effect of temperature and solid content on the viscosity. The results show that the viscosity of feedstocks decreases with the temperature and shear rate but increases with solid content. Activation energy and dlogn/dT of feedstocks both present two stages indicating the mechanism changes in the process. The activation energy and sensitivity of feedstocks are larger at lower temperature. It may be concluded to the effect of the melting of HDPE and LDPE. |
本系統中英文摘要資訊取自各篇刊載內容。