本計畫所使用材料為Al-8Zn-2.5Mg-1.5Cu-xZr (x= 0.02, 0.2 wt. %)高強度鋁合金，經鑄/鍛複合式製程(Casting/Forging hybrid process)後再進行T73時效熱處理，並探討不同鋯含量、模具型態與鍛造溫度等，對微結構包括抑制動態再結晶、晶粒細化之影響；接著探討對成型後鋁合金機械性質(UTS, YS, el.)與抗腐蝕能力(Ecorr、Icorr)的影響。近年來由於汽車、航太工業對於產品輕量化的迫切需求，學術界與業界皆致力於發展結構用高強度鋁合金，其目的為取代傳統鑄鋼做為新一代結構件用材，藉此達到降低油耗的效果。另學者研究發現，鑄/鍛複合式製程除了能夠消除鑄態孔隙、提升機械性質外，更可以有效降低生產成本，成本控制對製程選擇是相當重要的影響因素，因此本研究成果可提供業界生產與設計高強度鑄/鍛鋁合金機械性質與微結構的技術資料。 ;In this research, a casting/forging hybrid process is adopted to produce high strength aluminum alloy Al-8Zn-2.5Mg-1.5Cu-xZr (x= 0.02, 0.2 wt. %). The samples will carry out T73 aging treatment. This study is aim to assess different zirconium contents affecting the microstructure of treated samples, including dynamic recrystallization and grain refinement. In addition, the effect of deformation on microstructure, mechanical properties (UTS, YS, el.) and corrosion resistance (Ecorr、Icorr) would also be investigated. In recent years, thermomechanical processing on aluminum alloys is highly concerned and have been studied mainly on mechanical properties and microstructure; most of these studies used of wrought or extruded samples to carry out deformation. Few researchers have been conducted to focus on using casting/forging hybrid process. The effect of different zirconium contents on casting/forging aluminum alloys ‘s properties is interested and planned in this study (open-die forge/close-die forge, hot forged/cold forged, percent deformation, etc.).In term of fuel efficiency, automotive and aerospace industries are highly interested in developing light-weighting aluminum instead of steels. The pressure for using light-weight aluminum alloys is getting more intense. Furthermore, cast/forging process can bring about benefits of fully-eliminated the porosity of casting parts to enhance the mechanical properties and reducing production cost. Cost saving issue is an important factor for automobile parts. Conducting this proposed study can provide technical data, including material selection and optimization of process parameters for design and producing high strength cast/forged aluminum alloys.
