本研究透過實驗驗證氧化效應對鋁合金放射率的影響，實驗分別在真空腔體和大氣環境下量測五種不同鋁合金(AL 1100、AL 2024、AL 5083、AL 6061、AL 7005)在600 K、700 K與800 K時的放射率，然後透過多光譜輻射測溫法(MRT)去預測溫度，以了解氧化效應對溫度預測的影響，並且找出最佳的放射率模型。
在放射率的分析上，整體而言，不管有無氧化其放射率有相同的趨勢：(1)隨波長增加而放射率下降；(2)隨溫度上升而放射率上升。並且有氧化時的放射率高於無氧化時的放射率，其符合氧化將造成放射率上升的結果。(3)在無氧化時放射率不隨時間的增加而增加。相反的，當有氧化時放射率則會上升，因為氧化層隨時間增加而增厚。
對推測溫度而言，(1)試件有無氧化對於使用MRT時放射率模型的挑選上將有所不同，這是因為氧化效應會改變其放射率行為，因而適用不同的模型。(2)不管有無氧化，皆有模型推測溫度的平均溫度誤差百分比在4 %以內，表示MRT使用於鋁合金有不錯的預測溫度效果。(3)從最小平方法的曲線迴歸，可以看出實際放射率與MRT所推論出的放射率分佈越接近時，其推測的溫度勢必越準確。(4)MRT推測溫度的結果在高溫時可達更佳的準確性。(5)使用MRT推測溫度，增加波長數並無改善溫度誤差，故使用最小波長數即可，並且可以減少計算的時間。(6)不管有無氧化HRR、IST以及WLT*這三種模型皆有很好的預測溫度結果，其中氧化情況下又以HRR模型為最佳；無氧化情況則是WLT*模型。

In this study, experiments were conducted to examine the effect of surface oxidation on emissivity. The spectral emissivity were measured under an open-air heater system and a high-vacuum heater system for five different aluminum alloys (AL1100、AL2024、AL5083、AL6061、AL7005) at three temperatures (600 K、700 K、800 K). Eight emissivity models were used to examine the Multispectral Radiation Thermometry (MRT) for aluminum alloys in order to understand the effect of surface oxidation on temperature determination and find the best MRT emissivity model as well.
For aluminum alloys emissivity behaviors, overall similar trends are found under oxidized and unoxidized conditions. (1) Emissivity decreases with increasing wavelength. (2) Emissivity increases with increasing temperature. The emissivity of oxidized sample is higher than that of unoxidized sample and this demonstrates that oxidation causes the increase in emissivity. (3) The emissivity of unoxidized sample doesn’t change with time. However, the emissivity of oxidized sample increases due to the growing oxide layer with time.
For the examination of MRT emissivity models on aluminum alloys, (1) since the effect of oxidation changes the emissivity behaviors, different best models are found under conditions with and without oxidation. (2) Models having the percentage of average inferred temperature error under 4% are found for both oxidized and unoxidized samples. Therefore, MRT is suitable and applicable for aluminum alloy temperature determination. (3) For least-squares technique, the closer the inferred emissivity value and real one, the more accurate inferred temperature. (4) More accurate temperature measurement by MRT can be achieved in higher temperature. (5) Increasing number of wavelength doesn’t improve measurement accuracy while applying MRT. Therefore, it is sufficient to employ the required minimum number of wavelengths to save the time on computation. (6) Overall, three emissivity models, HRR、IST and WLT*, are able to achieve high accuracy in temperature prediction for both oxidized and unoxidized heating systems, especially HRR under oxidized condition and WLT* under unoxidized condition.

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