本研究採用50W的CO2雷射進行披覆試驗，並且搭配溫度感測儀與影像監測系統控制披覆層於不銹鋼板表面產生的積層效果，修正加工功率與披覆速度和焦點位置達到工件形貌上的平整與機械性質需求。探討不銹鋼304L粉末不同粒徑之熱傳導率、運送氣體流率對粉末流結構影響、粉末與雷射有效作用範圍變化因素，從而彙整參數範圍與對應趨勢。
數值計算部分是利用ANSYS分析工件於披覆時移動熱源在不同表面位置所產生的溫度變化，討論製程參數對熔池尺寸的影響。同時模擬不銹鋼粉末於噴嘴出口與雷射作用的動態溫度曲線，作為參數選擇依據。實驗方面，藉由單層披覆與多層披覆比較熱傳導率在三維空間的差異，單層披覆的散熱模式為鋼板而多層披覆散熱主要為工件本身，藉由輔助儀器監控溫度訊號分析多道次的熔池溫度與形貌關係。結果顯示，在多層披覆時使用雷射預熱板材可以提升工件平整度，粉末噴射角在30∘能夠與雷射有較佳的批覆效果，加工能量越強且披覆速度越低的情況硬度值會隨之上升，同時顯微晶粒會有細化現象。

In this study, a 50 W CO2 laser was carried out for cladding experiment.
Temperature sensing device and image monitoring system were adopted to monitor the layer deposition on stainless steel substrate. Processing was modified by different laser power, velocity, and focus position to reach an optimum morphology and mechanical properties of the cladding on demand.
The analyses for thermal conductivity of 304L stainless steel powder, transporting gas flow rate on the powder structure, and the interaction between powder and laser were made to find proper processing parameters, which were tested to demonstrate the feasibility.
ANSYS was used to calculate distribution of temperature for laser irradiates on moving substrate in the numerical part. Experimentally with single and multi-layer cladding, it is to compare the differences in 3D printing. Due to the clad profile cooling by substrate and workpiece itself, the equipment was applied to monitor temperature signal for multi-pass analysis and to predict the relationship between the melt pool temperature and cladding profile. The results show that a preheating substrate by laser can enhance flatness of the cladding profile. Besides, grain refinement phenomenon might occur at large power and low cladding speed, the hardness of workpiece would also increase.
Key words: Multilayer cladding；Temperature signal；Profile control

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