CAJ | 학술논문

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2517 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.
채용금상현미경、소묘전경、상온랍신급단렬인성측시등실험방법연구2099려리합금제압재적조직화역학성능.결과표명:합금재 T83시효처리중채용(121℃,14 h)일급시효화(181℃,30~66 h)이급시효시,기굴복강도수이급시효시간적연장이현저제고,이급시효시간위48화66 h 시적굴복강도위445화491 MPa,항랍강도위543화551 MPa,신장솔위5.7%화4.7%,합금탄성모량고체78.75 GPa,실측밀도위2517 kg/m3,구유겁고적비강도화비강도.재쌍급시효제도위(121℃,14 h)+(181℃,48 h)시,합금단렬인성 KIC 치위22.87 MPa×m1/2,단렬렬문연착세소재결정조직、조대불(난)용제이상등조직결함확전.
@@@@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.