新聞資訊
2099鋁鋰合金擠壓材的組織與力學性能
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更新時間：2015-08-18
采用金相顯微鏡、掃描電鏡、常溫拉伸及斷裂韌性測試等實驗方法研究2099鋁鋰合金擠壓材的組織和力學性能。
2099鋁鋰合金擠壓材的組織與力學性能Microstructure and mechanical properties of 2099 Al-Li alloy extrusion materials
采用金相顯微鏡、掃描電鏡、常溫拉伸及斷裂韌性測試等實驗方法研究2099鋁鋰合金擠壓材的組織和力學性能。結果表明：合金在T83時效處理中采用(121 ℃, 14 h)一級時效和(181 ℃, 30~66 h)二級時效時，其屈服強度隨二級時效時間的延長而顯著提高，二級時效時間為48和66 h時的屈服強度為445和491 MPa，抗拉強度為543和551 MPa，伸長率為5.7%和4.7%，合金彈性模量高達78.75 GPa，實測密度為2 517 kg/m3，具有極高的比強度和比剛度。在雙級時效制度為(121 ℃, 14 h)+(181 ℃, 48 h)時，合金斷裂韌性KIC值為22.87 MPa×m1/2，斷裂裂紋沿著細小再結晶組織、粗大不(難)溶第二相等組織缺陷擴展。
The microstructure and mechanical properties of 2099 Al-Li alloy extrusion materials were investigated by optical microscopy (OM), scanning electron microscopy (SEM), ambient temperature tensile testing and fracture toughness testing, and so on. The results show that, when the alloy is aged at T83 heat treatment which includes the first aging treatment (121 ℃, 14 h) and the secondary aging treatment (181 ℃, 30~66 h), the yield strength improves significantly with the increase of the secondary aging time. The yield strength, tensile strength and elongation are 445 and 491 MPa, 543 and 551 MPa and 5.7% and 4.7%, respectively, at the secondary aging time of 48 and 66 h. The elastic modulus is as high as 78.75 GPa and actual density is 2 517 kg/m3. The alloy has superior specific strength and specific stiffness. When the duplex aging is (121 ℃, 14 h)+(181 ℃, 48 h), the fracture toughness KIC?value of alloy is 22.87 MPa×m1/2. The crack expands along the microstructure defects, such as the fine recrystallization structure, the coarse insoluble second phase, and so on.