本研究首先利用高速火焰熔射法塗佈碳化鎢-鈷硬質保護鍍膜於不鏽鋼基板上，進行機械性質與耐腐蝕測試之量測，並利用光纖雷射進行再熔處理，期望能改進碳化鎢-鈷鍍膜之硬度、耐磨耗以及耐腐蝕等性能，搭配不同的雷射調控參數進行不同參數處理後性能之對比。此研究進行的性質測試包含: 奈米壓痕試驗機硬度測試、往復式磨粒磨耗測試、電化學阻抗譜耐腐蝕測試。並且利用電子顯微鏡觀察再熔處理前後之表面形貌差異。由表面形貌觀測發現，使用適當的雷射功率進行再熔處理，對於表面結構再熔燒結有顯著的幫助。研究顯示再熔處理對於硬度有一定幅度的進步，而不同雷射功率再熔產生的硬度數值相差最多落在5%。而在連續雷射模式下，雷射全功率30%進行再熔處理能達到最佳的耐磨耗性能。另外，在電化學阻抗譜耐腐蝕測試中，在連續雷射模式下雷射全功率40%進行再熔處理的實驗組別，達到最高電化學阻抗值，亦即其耐腐蝕特性最佳。

In this study, the tungsten carbide-cobalt hard coating is first coated on a stainless steel substrate by high-velocity oxygen fuel method, and the mechanical properties and corrosion resistance are measured. Fiber laser is used for remelting treatment, and it is expected to improve the tungsten carbide-cobalt coating’s hardness, wear resistance and corrosion resistance. The performance caused by different laser control parameters were compared. Tests conducted in this study including: hardness test by nanoindentation, reciprocating abrasive wear test, and electrochemical impedance spectroscopy test. The surface morphology before and after remelting was observed by electron microscope and optical microscope. It is found from the surface morphology that remelting with appropriate laser power is able to remelt the surface structure. Results show that remelting treatment leads to improvement in hardness by 5%. With the continuous laser mode, 30% of the laser power of remelting achieves the best wear resistance performance. In the Electrochemical Impedance Spectroscopy corrosion tests, the specimen of 40% laser power remelting in continuous laser mode reached the highest electrochemical impedance value. It means that 40% laser power yields best corrosion resistance among all the cases.

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