열분석법에 의한 2090 Al-Li 합금의 시효거동에 미치는 In 첨가의 영향 = The Effects of Indium Addition on the Aging Behaviors of 2090 Al-Li Alloy by Diffrential Scanning Calorimetry

다국어 초록 (Multilingual Abstract)

The effects of indium on the phase transformation of 2090 Al-Li alloys has been studied with a differential scanning calorimeter (DSC), a transmission electron microscope(TEM), and a micro-hardness tester at the temperature ranges of 130℃∼220℃. The results show that indium addition to the 2090 Al-Li alloy retards the formation of prior precipitate(precursor) and δ´phase, whereas it accelerates the formation of T₁ and θ´(especially θ´phase). Above 190℃, the formation of δ´phases is retarted than those at 130℃ and at 160℃. The addition of 0.15wt% indium increases the hardness at the early stage of aging. The cause of this effect is attributed to the formation of GP zone. The main phases, in peak aged condition of indium free 2090 alloys are δ´and T₁; indium bearing 2090 alloys are θ´and T₁ (especially θ´Phases).