本文藉由套裝軟體Ansys Fluent建立暫態二維軸對稱模型，模擬固定電子束直接加熱純鈷、純鉭金屬，材料邊界藉由水冷銅坩鍋散熱，並且考慮熔池表面張力效應(馬蘭戈尼效應)、蒸發熱損失。探討不同電子束能量、電子束半徑，對金屬熔池形狀、表面溫度以及純鈷、純鉭金屬蒸發熱損失之影響。
其模擬結果顯示，在熔煉純鈷金屬過程中，其熔池表面最高溫度、熔池表面平均溫度在短時間內會達到穩定狀態，且熔池主要受馬蘭戈尼效應之影響，產生一較寬、較淺之熔池形狀。
固定電子束半徑，增加電子束能量進行熔煉，將會增加表面之輻射熱損失及蒸發熱損失，不僅增加純鈷金屬之損耗，亦會浪費能量，降低熔煉效率。
固定電子束能量，以較大之電子束半徑進行熔煉，可以使熔池表面最高溫度較小、有效地增加熔池寬度、同時減少純鈷金屬之蒸發熱損失，故應以電子束半徑較大者進行電子束熔煉。
以較大電子束半徑進行純鉭金屬之熔煉，雖可降低熔池表面過熱之問題，卻無法使熔池之寬度較大，故必須再增加電子束能量進行熔煉，並且再提高水冷銅坩鍋之冷卻效果。

In this study, a numerical simulation model is developed to investigate the flow and heat transfer characteristics of molten pool for pure cobalt and tantalum during electron beam melting (EBM). This model also considers the coupled effects of buoyancy and Marangoni forces, and radiation and evaporation losses. Radiation and evaporation losses of cobalt during EBM increase with the increase of beam power, while they decrease with the increase of beam radius. Furthermore, the increase of beam radius will decrease the temperature of pool surface and will make pool wider. Based on these results, it is recommended to use larger beam radius during EBM. It is not efficient to use the parameters set in this study to melt tantalum. In addition to larger beam radius, larger beam power and enhanced water cooling are needed in the future research.

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