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2099铝锂合金挤压材的组织与力学性能
发布人：上海艾荔艾金属材料有限公司www.shailiai.com
更新时间：2015-08-18
采用金相显微镜、扫描电镜、常温拉伸及断裂韧性测试等实验方法研究2099铝锂合金挤压材的组织和力学性能。
2099铝锂合金挤压材的组织与力学性能Microstructure and mechanical properties of 2099 Al-Li alloy extrusion materials
采用金相显微镜、扫描电镜、常温拉伸及断裂韧性测试等实验方法研究2099铝锂合金挤压材的组织和力学性能。结果表明：合金在T83时效处理中采用(121 ℃, 14 h)一级时效和(181 ℃, 30~66 h)二级时效时，其屈服强度随二级时效时间的延长而显著提高，二级时效时间为48和66 h时的屈服强度为445和491 MPa，抗拉强度为543和551 MPa，伸长率为5.7%和4.7%，合金弹性模量高达78.75 GPa，实测密度为2 517 kg/m3，具有极高的比强度和比刚度。在双级时效制度为(121 ℃, 14 h)+(181 ℃, 48 h)时，合金断裂韧性KIC值为22.87 MPa×m1/2，断裂裂纹沿着细小再结晶组织、粗大不(难)溶第二相等组织缺陷扩展。
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.