奈米碳管填料對樹脂結合金剛砂砂輪性能之研究

Abstract

在砂輪的製造中，除了磨粒與結合劑外，常常會加入其他填料改良砂輪的特性，增強砂輪的效能，填料種類繁多，從金屬、陶瓷及奈米粉末等各式各樣材料皆有相關研究提出使用。本研究嘗試將奈米碳管當作填料，並以金剛砂(Corundum)為磨粒，酚醛樹脂為結合劑，三者混合後採冷壓方式製成砂輪，探討奈米碳管填料對金剛砂樹脂砂輪特性的影響。 在掃描式電子顯微鏡(SEM)的觀測下，發現奈米碳管在砂輪內部共會出現三種型態:1. 奈米碳管交織成網狀而包覆在磨粒上、2.奈米碳管成網狀結構連結固化後之樹脂基、3.形成如棉球般的團簇充填在空隙與氣孔之間。接著在觀測砂輪破斷面以及內部密度的計算下發現，奈米碳管可以減小氣孔使結構緊密，但是因為本身密度甚小，因此亦會降低砂輪密度，砂輪試片整體的密度就在此兩種作用的消長之下而改變。在進行抗壓強度測試結果發現，在樹脂含量高(30%)的情況下，隨著奈米碳管含量增加，抗壓強度強度會上升；樹脂含量適中(15%)時，抗壓強度隨奈米碳管含量增加有先升後降的趨勢；而在樹脂含量少(7%)的情況下，抗壓強度則隨著奈米碳管增加而下降。在磨削試驗中，實驗結果顯示，在樹脂、金剛砂、奈米碳管含量分別為15%、83%及2%的重量配比下，會有最好的磨削效果，其工件表面粗糙度Ra達0.3969μm，磨削前後Ra改善率達到66%。

In the manufacture of grinding wheel,the fillers are often added to grinding wheel to enhance the performance. There are many kinds of filler materials such as metals,ceramics and nano-powder which are all sorts of fillers. This study attempt to treat carbon nanotube(CNT) as the filler. By using the scanning electron microscopy (SEM),we observed that there are three types of carbon nanotube in the grinding wheel: 1.Carbon nanotubes are woven into mesh and coated on the abrasive. 2.Carbon nanotubes performs a net structure which is linking the resin-based. 3.A cotton ball-liked clusters which are filling in the gaps and holes. In the fracture surface observation and the density data of grinding wheels,we found that carbon nanotubes can reduce the pore structure. From the compressive strength test, results showed that the compressive strength is increasing with the CNT content increased for the case of high resin content. And,with CNT increased,the compressive strength is increasing at first and decreasing afterwards for the case of moderate resin content While the case of moderate resin content, the compressive strength is decreasing with CNT content increased.In the grinding experiment,surface roughness of work-piece is able to be improved by 66% and Ra reaches 0.3969μm under the condition of resin content 15wt%, corundum 83wt%,CNT 2wt%.