材料及製程參數對射出成形元件品質影響之研究

王鴻儒(Hung-Ju Wang)

指導教授 ： 黃坤祥

國立臺灣大學/工學院/材料科學與工程學研究所/碩士(2005年)

https://doi.org/10.6342/NTU.2005.00112

摘要

金屬粉末經壓製或射出後必須經燒結才有足夠之機械性質，但在未燒結前必須具備一相當之強度，以應付搬運過程中工件彼此間以及與外物碰撞所遭受之應力。因此，本實驗的主要目的即是藉由調整黏結劑配方及製程參數探討其對射出成形元件生胚強度的影響。
在粉末射出成形中一般都使用聚丙烯或聚乙烯來當做骨架黏結劑，本實驗比較不同聚丙烯和聚乙烯胚料的黏度及生胚強度作為評論的標準，由結果顯示，聚乙烯的胚料在各製程中都能有效的控制，且具有好的黏度及生胚強度，聚乙烯的效果遠比聚丙烯來得佳。高溫石蠟並不能如所期待地減少生胚的收縮量。另外，Mg-St和Li-St的添加雖可改善射出品質，但並沒有預期的強化效果，反而使拉伸強度明顯的下降。
在溶劑脫脂的階段，試片的尺寸變化之結果顯示，試片在脫脂時會產生膨脹的現象，此乃因溫度差異造成的熱膨脹及黏結劑在溶劑中的膨潤反應所造成。此外，黏結劑脫脂溫度、黏結劑含量及黏結劑的種類都會影響溶脫時的膨脹量。

關鍵字

粉末射出成形 ； 生胚強度 ； 毛細流變 ； 脫脂 ； 膨脹儀

並列摘要

Metal powder compacts and metal injection molded(MIM) parts are usually fragile before sintering. This low strength caused damages during handling. For this reason, the objective of this study was to examine the effects of binder selection and molding parameters on the green strength of MIM parts.
　　Polypropylene and polyethylene were generally used as the backbone binder in MIM. Thus, various PP and PE were examined for their advantages and disadvantages. The results show that PE is better than PP. High Temperature Paraffin Wax(HTPW) was examined, but no advantages. Addition of the Mg-St and Li-St can improve quality of molding, but no important in strengthen.
　　During the solvent debinding, swelling was observed when the spec-
imens were immersed in the solvent. The major causes were the thermal expansion due to the temperature rise of the specimens and the swelling reaction between the binder and solvent. The amount of expansion was also related to the temperature, amount of the binder, and the type of the binder selected.

並列關鍵字

Powder injection molding (PIM) ； green strength ； capillary rheology ； debinding ； swelling dilatometer

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