由於鋁合金吳有質輕、強度高、易加工度耐腐蝕性佳之特性，在工
業界中廣泛受到使用。本研究針對工業用純鋁1100-H18及市面上常
用之6061-T6鋁合金，立用惰氣鎢極電弧銲，以ER4043銲線為填料，
進行平頭對接。經由銲後熱處理、拉伸試驗、微硬度測量、金相顯
微組織觀察、及SEM破斷分析，探討銲件熱處理前後之機械性質，
和微觀結構變化情形。期望藉此研究提供鋁材銲接之應用與參考。
從實驗結果顯示，1100-H18雖屬非熱處理型鋁合金，經由施予160
℃、４小時之熱處理後，伸長率及微硬度稍降，但抗扯強度則有所
提昇。1100-6061異種鋁材銲件，經施以所設計之銲後熱處理後，在
1100-H18部分對其銲件機械性質之提昇助益不大。而6061-T6銲件
經實施1小時530℃固溶及18小時160℃之人工時效全程熱處理後，
銲件母材、熱影響區及銲道之抗拉強度、微硬度值均大幅提昇，超
越原有母材之強度。銲件拉伸破斷面經由SEM觀察，拉伸破壞原因
係屬於延性破壞。

Because the characteristics of "high strength to weight" ratio, easy formability and good corrosion resistance, aluminum alloy have been applied extensively in industry. The purpose of this research was to systematically study the weldability of aluminum alloys weidments under Gas Tungsten Arc welding (GTAW).The base metals used are 1100-H18 and 6061-T6 with filler metal of ER4043. A series of post weld heat treatment. tensile testing, microhardness testing, optical metallography and SEM were used to determine and analyze the relationship between mechanical properties and microstructure.
A series of experiment results indicated that the 1100-H18 (non-heat treatable) under 160℃, 4 hours artificial aging treatment can reduce their microhardness and elongation slightly, however, their ultimate tensile strength can be enhanced. 6061-T6 weldment under 530℃, 1 hour solution heat treatment and 160℃, 18 hours artificial aging treatment can greatly enhance the overall mechanical properties of base metal, heat affected zone and fusion zone. Besides, SEM observations on the tensile tested specimen showed a ductile fracture surface.