本文係利用工具型放電機進行放電被覆加工實驗，在矽油為放電加工液，石墨為電極材料的條件下，探討在電壓、峰值電流、脈衝時間與休止時間等參數條件下對被覆層形成的影響。最後使用掃瞄式電子顯微鏡觀察被覆層表面與X光繞射儀觀察被覆層成份，探討實驗參數對被覆層之影響。 分析結果顯示，設定峰值電流5A、脈衝時間為100us、休止時間10us時可以得到一個純度比較高的碳化矽被覆層。 實驗結果得知，以無毒性的矽油取代煤油作為放電加工介電液，不僅可以是矽原子的來源，同時也可以和石墨電極材料合成碳化矽成份，被覆在鉬金屬表面形成被覆層。由於矽油含有矽氧鍵，因此在放電披覆的過程中，無法避免氧化矽的生成，此需進一步研究探討，例如改用矽電極取代石墨，在煤油中進行放電被覆。 This research investigates the effects of electrical discharge parameters including open voltage, peak current, pulse duration and pulse off time on coating of SiC at Mo metal. The Electrical Discharge Coating (EDC) process was conducted at an instrumental electrical discharge machine. Instead of kerosene dielectric fluid and copper electrode, the silicone oil and graphite electrode material were used in this study. The coating layer’s ingredients and the effects of experimental parameters on coating layer were investigated by using a scanning electron microscope (SEM/EDX) and X-ray diffractometer. The results show that setting the discharge parameters of peak current= 5A, pulse duration=100 us, and pulse off time=10us can obtain a higher purity SiC layer on EDCed Mo metal. Besides, experimental results also showed that the non-toxic silicone oil not only acted as the dielectric fluid but also provided the source of silicon atoms for reacting with graphite particle to synthesize the SiC layer on the molybdenum surface. Due to silicone oil containing silicon-oxygen chemical bond, it can’ n avoid the formation of SiO2 whithin the electrical discharge coating process. Therefore, it may go further to adopt the appropriate electrode materials such as silicon electrode in kerosene to purchase more pure SiC layer on Mo metal in the future.
