磨料噴射技術應用於精微拋光之研究

A Study on Micro Polishing by Abrasive Jet Technology

官君宇(Chun-Yu Kuan)

指導教授 ： 顏炳華

國立中央大學/工學院/機械工程學系/碩士(2006年)

摘要

本研究主要建構出一自動磨料噴射精微拋光系統，並以放電加工後SKD61模具鋼表面作為改善對象，探討磨料噴射精微拋光法對放電表面拋光改善效果。

研究主要分為兩大部分，首先自行組裝自動磨料噴射精微拋光系統，探討磨料噴射精微拋光法的加工特性與系統各參數加工極限，再利用田口實驗計畫法進行實驗規劃，以獲得磨料噴射精微拋光法各參數對表面粗糙度改善率與材料移除量的影響與最佳水準所在。接著由所獲得之最佳參數組合依續探討改變加工時間、加工路徑、初始放電面、添加劑種類、磨料種類與粒徑等加工參數，以追求磨料噴射精微拋光法對放電表面拋光至鏡面改善效果。

實驗結果發現以自行開發之自動磨料噴射精微拋光系統配合田口實驗所獲得之最佳參數組合，可將表面粗糙度1.03μm Ra (7.74μm Rmax)的放電加工面降至0.13μm Ra (0.90μm Rmax)，改善率達87%，且表面呈現近似鏡面反射效果。另外研究亦探討研磨後之工件表面材料特性，發現利用混合SiC 磨粒進行噴射拋光加後之工件具有SiC嵌入表面效應，由EDS 定量分析結果，其表面SiC含量有明顯增加，且表面微硬度亦會增加。

關鍵字

田口品質工程 ； 表面粗糙度 ； 磨料噴射 ； 拋光 ； 放電加工

並列摘要

This research mainly constructs out an automatic abrasive jet system for micro polishing machining, and takes EDMed SKD61 surface as target of improving. The EDMed surface are investigated to improve the surface polishing effect by abrasive jet micro polishing machining (AJMPM) after processing.

The study is divided into two major parts. First, the machining characteristic of AJMPM and the limit of system parameters will be discussed. Then, making use of Taguchi Method to obtain the optimization of manufacturing process parameters for surface roughness improvement and material removal weight on AJMPM. Second, the best combination of parameters is used to continue discussing the different of machining time, machining path, initial surface roughness, kinds of additive, abrasive mesh and kinds of abrasive in turn. Expecting that the EDMed surface can be improved like a mirror after AJMPM.

From the experimental results find that using the best combination of parameters by Taguchi Method on automatic abrasive jet micro polishing system developed by myself, the surface roughness value can drop from 1.03 μmRa to 0.13 μmRa and 7.74 μmRmax to 0.90 μmRmax, the improvement rate up to 87% and the surface is similar to a reflection mirror. Furthermore, studies are also investigated the surface characteristic of workpiece after machining. From EDS quantitative analysis result reveal that using the SiC abrasive after AJMPM, the SiC content on workpiece surface is going to increase obviously and micro hardness of surface will also increase owing to the surface insertion effect (SiC particles).

並列關鍵字

abrasive jet machining(AJM) ； polishing ； electrical discharge machining(EDM) ； Taguchi Method ； surface roughness

參考文獻

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