本研究提出一種尋找熔池放射率比值的方法以及應用於雙色高溫計中以達到即時量測熔池之溫度場，利用推導出之運算式與熱傳模擬之結果，再將模擬結果之表面截點溫度值截取出，並根據所提出的後處理方法得到高溫計之預讀溫度，最後根據實驗找到在雙色高溫計兩波段之放射率，並形成比值。根據此比值設定於高溫計之比值模式，經實驗量測後與計算之預讀溫度相符合，並且經過兩個不同雷射功率之實驗驗證，得到相互匹配的結果。在此實驗中，有以下因素會影響材料之放射率，如金屬粉層厚度、金屬粉末粒徑大小分布、金屬粉末種類以及高溫計的測溫視場大小等。此外，若為同一批金屬粉末，只要粉層厚度改變，放射率則需要根據提出之流程方法重新求得。

This research develops a technique to estimate the emissivity ratio of a two color pyrometer in measuring the melting pool of stainless steel 316L powder during selective laser melting process. The goal is to achieve the real-time temperature measurement, which is based on a proposed model and the result of heat transfer simulation, then extract the temperature of those nodes on surface in simulation to do the post processing which was developed in this research, then could obtain the computed temperature for pyrometer. Finally, basing upon the computed temperature could find out the emissivity values at each wavelength in pyrometer experiment, and forms them into an emissivity ratio. It is found out that the two experimental results based on the emissivity ratio correspond to the computed temperature. In experiment, there are several factors that affect emissivity values such as the layer thickness of metal powder, the size distribution of metal powder, the kind of metal powder and the measuring spot size of pyrometer. Besides, if the metal powder is in the same group, the powder layer thickness changes, the additional experiments for finding the emissivity ratio will have to do.

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