鎳鋅銅鐵氧磁體元件之射出成形製程研究

Injection Molding of Ni-Zn-Cu Ferrite Components

李慶基(Ching-Chi Li)

指導教授 ： 陳貞光

國立臺北科技大學/工程學院/材料及資源工程系研究所/碩士(2010年)

摘要

本實驗以陶瓷射出成形製程製備鎳鋅銅鐵氧磁體元件為目標，從射料之固含量、黏結劑選擇、黏結劑含量、混練方式、以及脫脂製程等參數進行探討。本研究調整不同固含量47 vol.%–55 vol.%及黏結劑中主黏結劑聚丙烯與次黏結劑石蠟之比例為1.00~2.82，以不同的混練順序與方法尋找最佳的原料配比製備鎳鋅銅鐵氧磁體元件，並以小型射出成形與大型射出成形實驗探討不同射料配比之成形性，以及粉末與黏結劑之均勻性。
在相同的固含量下，聚丙烯與石蠟比例為1.47時、聚丙烯與石蠟預先混合、或添加6 vol.%的硬脂酸皆能縮小射件之孔隙尺寸。此外，以適量的硬脂酸預先披覆原料粉末能有效改善其團聚現象，提升射料之流動性，亦有助於縮小射件孔隙尺寸。
55 vol.%為鎳鋅銅鐵氧磁體之最高固含量，固含量提高雖然可以提升燒結體的緻密程度、收縮率亦可降低，但提高固含量射料流動性差、不利於成形，為了避免短射或射件產生裂縫，必須提高射出速度與溫度。本研究中的較佳固含量為50 vol.%與53 vol.%。

關鍵字

陶瓷射出成形 ； 鎳鋅銅鐵氧磁體 ； 黏結劑 ； 脫脂 ； 燒結

並列摘要

The current study is to prepare Ni-Zn-Cu ferrite via ceramic injection molding process. Process parameters including solid loading fraction, binder system, content of binders, mixing procedures and debinding processes are considered.
The fraction of solid loading is controlled to range from 47 vol.% to 55 vol.%. The binder system is combined using polypropylene and paraffin wax at ratios between 1.00 and 2.82. The feedstock mixtures are then injected using mini-injection molding and injection molding machines. Optimum feedstock mixture formula are thus determined by the quality of sintered materials.
It is found that, at constant solid loading content, the optimized ratio of polypropylene and paraffin wax is 1.47 by pre-mixing the two binders. 6 vol.% of stearic acid addition is also found to decrease pore size in the sintered materials. In addition, stearic acid pre-coating can also help disperse the powders and decrease viscosity of feedstock.
The upper limit of Ni-Zn-Cu ferrite solid loading fraction is 55 vol.%. Although the increase of powder content can reduce the amount of shrinkage, high solid loading content also lead to increased viscosity. To avoid short shot and crack formation in the sintered materials, both the injection rate and injection temperature has to be increased. It is found that 50 vol.% and 53 vol.% are the optimum solid loading fraction.

並列關鍵字

CIM ； Ni-Zn-Cu ferrite ； binder ； debinding ； sintering

參考文獻

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