本論文針對AA6061與Ti-6-Al-4V之焊接接合進行研究，使用自主開發之金屬箔材積層製造（Laser Foil Printing, LFP）進行加工，達成同時具高強度以及具薄金屬間化合物接面之鋁鈦金屬接合工件。研究中將比較以鋁合金以及鈦合金分別做為箔材和基板進行疊層的兩種策略優劣，以單道測試決定製程參數圖後進行數層疊層之橫截面比較孔隙率，得到以Ti-6Al-4V作為箔材堆疊至AA6061基板擁有小於0.1%孔隙率之較佳品質結果；並利用有限元素法之3D數值模擬進行焊接時之熔池模擬，得到熔池尺寸小於10%誤差值之模擬結果，數值模擬可用於經由雙材料至單一材料過程之雷射參數變化最佳化；除了孔隙率比較，也利用掃描式電子顯微鏡（Scanning Electron Microscope, SEM）以及能量色散光譜儀（Energy-Dispersive X-ray Spectroscopy, EDS）進行元素之線分析以及面分析觀察金屬之混合情況，指出鈦疊層在鋁上之策略擁有19μm之較薄混合層。爾後為了改善鈦合金積層製造擁有高殘留應力之影響，於疊層至純鈦部分之後使用點焊策略減少殘留應力以及於完成後進行金屬加熱時效釋放應力，並將完成之工件加工成拉伸試驗棒以進行z軸疊層方向之接合面拉伸試驗。最後以X光繞射（X-ray Diffraction, XRD）將疊層至1mm、2mm、3mm，三種狀態之樣品進行元素分析，並使用背向散射電子繞射（Electron Backscatter Diffraction, EBSD）進行金屬熱時效處理前後樣品之晶粒分析。本研究為鋁鈦合金之焊接提供使用LFP技術的可行性，在積層製造以及異質金屬焊接領域之未來發展提供貢獻。

This thesis investigates the joining of AA6061 aluminum alloy and Ti-6Al-4V titanium alloy using a self-developed Laser Foil Printing (LFP) system to fabricate high-strength aluminum–titanium dissimilar joints with thin intermetallic compound (IMC) interfaces. Two deposition strategies, in which aluminum alloy and titanium alloy were alternately used as the foil and substrate, were systematically compared. Processing maps were established through single-track experiments, and multilayer samples were fabricated for cross-sectional porosity evaluation. The Ti-6Al-4V foil-on-AA6061 substrate strategy achieved the best performance, exhibiting a porosity below 0.1%. A three-dimensional finite element model was developed to simulate the melt pool, and the simulated melt pool dimensions agreed with the experimental results within 10%, demonstrating its capability for optimizing laser parameters during the transition from dissimilar to homogeneous material deposition. SEM coupled with EDS elemental mapping and line scanning further confirmed that the Ti-on-Al strategy produced a thinner mixed layer of approximately 19 μm. To reduce residual stress, Spot Pattern Scanning (SPS) was introduced after the deposition transitioned to homogeneous titanium, followed by post-aging heat treatment. The fabricated samples were machined into tensile specimens for Z-axis tensile testing. Material characterization was further conducted using XRD on samples with deposition heights of 1, 2, and 3 mm, while EBSD was employed to examine the evolution of grain structure before and after aging heat treatment. The results demonstrate the feasibility of Laser Foil Printing for aluminum–titanium dissimilar-metal joining and highlight its potential for future applications in additive manufacturing and dissimilar-metal welding.

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