微銑削加工表面刀紋改善之研究

本研究利用微銑削平面加工探討切削刀紋之成因及改善的方法，刀具路徑粗加工後，表面會殘留刀具路徑留痕高，欲以較細微之刀具路徑節距去除留痕高，會殘留細微之刀紋。經由衝擊共振實驗以及頻域分析，發現刀紋之成因與結構特性及偏擺量無關，推測刀紋成因應為部份材料被推擠犛切以及產生彈性變形無法被刀具去除而成。本研究加工黃銅合金和純鎳，加工黃銅合金每刃進給量至0.4μm/flute以上；刀具皆可有效切削除去表面刀紋，由於純鎳抵抗塑性變形能力較佳，每刃進給量需提昇至0.8μm/flute以上才可去除表面刀紋。過小之進給量使得切削表面材料有被推擠之現象，可得切削刀紋成因為刀具犛切材料而形成，但提高每刃進給量使得切削力變大，表面粗糙度變差。以水基切削液進行加工，可發揮較佳之潤滑性降低切削力，與其他切削環境比較之下，在不同進給量皆可得到較好之表面粗糙度，使用水基切削液，可使每刃進給量較低時，切屑較易流動，工件材料可順利被去除，有效改善一般低進給下的切削刀紋，在每刃進給量為0.16μm/flute加工黃銅合金時，表面粗糙度Ra僅有0.026μm，且表面未具有切削刀紋。

關鍵字

刀紋；微銑削；犛切；每刃進給量；水基切削液

並列摘要

An experimental investigation on the reasons of surface texture, and the improvements of this phenomenon by flat surface micro-milling was conducted in this study. After rough machining, marks on the surface caused by scallop height, can be eliminated by using small pitch of tool path. But some slight textures on the surface still remain. By impact test and frequency domain analysis, it was found that the reasons of surface textures were little related with dynamic characteristics of machine tool structure and tool runout. Brass and pure nickel was machined in this study. Surface textures can be effectively eliminated when feed raises to 0.4 and 0.8μm/flute in brass and pure nickel machining, respectively. The reason of textures is that the partial material was plowed and elastic deformation occurred. Hence the material was not able to remove by cutting tool in a low feed. But unpreventablely, raising feed causes bad surface roughness. Adding water base fluid during the machining process can obtain better surface roughness whether the feed is high or not, even in a very low feed which the condition is good for the surface texture. According to the result, the feed of 0.16μm/flute is adopted in brass machining, and the good surface roughness Ra, which is only 0.026μm, can be obtained without appearance of surface texture.

並列關鍵字

surface texture ； micro milling, ； plowing ； feed per flute ； water base fluid

參考文獻

[13] 孫韓岳，單晶鑽石銑刀設計及其於微銑削鏡面加工之應用，國立台灣大學機械工程所碩士論文，民國九十六年六月。

[14] 黃春霖，微銑削主軸轉速與表面粗糙度關聯性之研究，國立台灣大學機械工程所碩士論文，民國九十八年八月。

[21] 江致毅，五軸工具磨床振動分析模式，國立虎尾科技大學機械與機電工程研究所碩士論文，民國九十八年七月。

[1] 陳順同，微CNC綜合加工機研發與微元件製造研究，國立台灣大學機械工程學研究所博士論文，民國九十四年七月。

[2] A. G. Rehorn, J. Jiang and P.E. Orban, “Modelling and Experimental Investigation of Spindle and Cutter Dynamics for a High-precision Machining Center,” International Journal of Advanced Manufacturing Technology, Vol. 24, Issue 11-12, 2004, pp.806-815.

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微銑削加工表面刀紋改善之研究

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