鋁合金輕金屬的應用與關鍵製造技術

由於國際間對於節能減碳的要求日趨嚴格，故目前全球各大汽車廠多已將「汽車輕量化」作為新技術開發的首要目標。現階段，採用輕質材料來減輕汽車重量是最有效的辦法。鋁合金的密度(2.7g/cm3)僅為鋼鐵(7.8 g/cm3)材料的1/3，比強度高、比剛性高、抗衝擊性能良好、耐腐蝕佳、高導熱、易表面處理、良好加工成形性以及高的回收率等，故成為汽車輕量化之關鍵與理想的材料之一。汽車部件所採用之鍛造材鋁合金，大抵為6000系及最高強度的7000系鋁合金，以可熱處理強化之鋁合金板材為主。對可熱處理型的鋁合金而言，最基本的步驟包括步驟固溶處理、低溫淬火、時效處理。近年來，新發展之溫成形、熱成形及超塑性成形術等，可以克服鋁合金不易成形與杜絕或減少缺陷的發生。其中電動車多應用沖壓溫成形(美國發展此技術為主)、熱成形(歐洲國家為主)製程，而航太產業則大量應用超塑性成形技術。

Due to the increasing requirements for energy saving and carbon reduction, many world major automobile manufacturers have made "vehicle light-weighting" as the primary goal. At this stage, the most effective way to reduce the weight of vehicles is to use lightweight materials. The density of aluminum alloy (2.7g/cm3) is only 1/3 of that of steel (7.8g/cm3). Aluminum has high strength, high specific rigidity, good impact resistance, good corrosion resistance, high thermal conductivity, easy surface treatment, good processing and forming properties, and high recycling rate. So it turns to be one of the keys and ideal materials for automotive light weighting. Heat treatable reinforced aluminum alloy sheets such as 6000 series and the highest strength 7000 series aluminum are used for automotive parts. Basic heat treatment processes include solid solution treatment, low temperature quenching and aging treatment. In recent years, the newly developed thermoforming, hot forming and superplastic forming techniques can overcome the forming difficulty of aluminum alloys and eliminate or reduce the occurrence of defects. Stamping, warm forming (mainly developed in the U.S.) and hot forming (mainly in European countries) are mostly used for electric vehicles while superplastic forming is applied in aerospace industry.