本研究主要以選擇性雷射燒熔(Selective laser melting, SLM) 3D列印機制作為數值模擬計算之建構模型，模擬列印過程中金屬粉末及基板受雷射能量所產生熱傳行為及相變化過程中之溫度效應，並探討不同雷射控制因子對金屬粉末及基板燒蝕後熱效應區之影響。再藉由對比選擇性雷射燒熔(SLM)實驗列印出金屬物件之熱影響區域分佈，分析數值模擬方法與實驗受雷射控制參數之影響，評估數值模擬方案對選擇性雷射燒熔(SLM)實驗之控制範圍及可靠程度。
數值模型建構為採用COMSOL Multiphysics多重物理量耦合模擬軟體建立理論架構，由熱傳方程式導入相變化方程式，再由雷射輻射熱傳方程式及雷射能量方程式，建立選擇性雷射燒熔(Selective laser melting, SLM)列印過程對金屬粉末燒熔之模型並探討金屬粉末熔融區(Melting zone, MZ)及金屬基板熱影響區(Heat affected zone, HAZ)之控制因子。根據數值模擬與實驗結果，雷射輸入功率越大，則熔融區之最大深度、最大寬度及熱影響區厚度都會隨之增加，而雷射掃描速度越慢對熔融區之最大寬度及最大深度亦會有增加情形且對熱影響區也有顯著增厚的趨勢，但由實驗得知雷射掃描速度過慢時卻會造成過度加熱而使熔融區之最大深度相對縮小。比對實驗與數值模擬結果，相關控制參數之影響趨勢大致相同，但在熔融區之深度、寬度及熱影響區之數據大小，數值模擬結果皆小於實驗數據。此誤差可能為液態金屬固化所造成之材料形變間接影響熔融區之深、寬度，同時粉末間之孔隙率亦可能會影響雷射光在其中折射或反射情形，導致金屬粉末或基板受熱情況不同，而造成熱影響區域有所改變，因此再詳加探討相關影響條件，便可望能更接近SLM列印結果。

This study focuses on selective laser melting (SLM) process, the melting zone of the powder and heat affected zone of the substrate influence the quality of 3D printing objects. In the present study, the controlling factors of SLM process are the laser power, laser scanning velocity, and thickness of powder bed. Because the technology of SLM is developing, the finite element model of SLM process is necessary to forecast the results. In order to check the accuracy of the simulational model, the experiment with same conditions is used to contrast two results. In this case, the material of powder is SKD61, and the substrate is S45C. After SLM printing, the depth, width, and length of melting zone, and heat affected zone of the substrate are measured to realize the influence of laser controlling parameters. Meanwhile, discussing the tendency for different combinations of laser parameters.

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