采用不同焊接压力对2060-T8铝锂合金进行了顶锻式摩擦塞补焊试验研究,分析了接头微观组织特征,第二相分布规律以及力学性能。结果表明:增大焊接压力可有效消除接头未焊合及孔洞缺陷。接头热影响区晶粒尺寸增大,热机械影响区及塞棒热机...采用不同焊接压力对2060-T8铝锂合金进行了顶锻式摩擦塞补焊试验研究,分析了接头微观组织特征,第二相分布规律以及力学性能。结果表明:增大焊接压力可有效消除接头未焊合及孔洞缺陷。接头热影响区晶粒尺寸增大,热机械影响区及塞棒热机械影响区晶粒发生明显塑性变形,母材与塞棒之间产生了细小的等轴晶组织。接头不同区域较母材均发生软化,硬度最低值出现在塞棒热机械影响区,约为90 HV。当焊接压力为30 k N时,接头抗拉强度最高,达到378.9 MPa,断后伸长率为5.9%,接头系数为0.746。接头断裂方式为韧性断裂。展开更多
Friction stir welding was used to join two AA2060-T8 plates,and then the effect of precipitate evolution on microstructure and corrosion behavior of the joint was investigated.The evolution of precipitates on the top ...Friction stir welding was used to join two AA2060-T8 plates,and then the effect of precipitate evolution on microstructure and corrosion behavior of the joint was investigated.The evolution of precipitates on the top surface of the joint was characterized by scanning electron microscopy and transmission electron microscopy.The corrosion behaviors of different regions in the joint were investigated by an electrochemistry method and an alternating salt spray exposure.The corrosion was mainly dependent on the nature of precipitates in each region of the joint.The shoulder affected zone had the worst corrosion resistance as a result of the re-dissolved ofθ′(Al2Cu),T1(Al2CuLi)andδ′(Al3Li)phases,the formation of intergranular precipitates and precipitate-free zones.However,the thermomechanically affected zone had a slightly improved corrosion resistance because it had no intergranular precipitates.The heat affected zone and base metal had the best corrosion resistance.展开更多
The corrosion behavior of aluminum alloy 2024-T3 was studied in 3.5% NaCl solution with two fluorescence quinoline compounds named 8-hydroxy-quinoline(8HQ) and 8-hydroxy-quinoline-5-sulfonic acid(HQS). The open circui...The corrosion behavior of aluminum alloy 2024-T3 was studied in 3.5% NaCl solution with two fluorescence quinoline compounds named 8-hydroxy-quinoline(8HQ) and 8-hydroxy-quinoline-5-sulfonic acid(HQS). The open circuit potential(OCP) test result indicates that both compounds change the alloy corrosion potential by adsorbing on the electrode surface. Polarization measurements show that 8HQ is a mixed type inhibitor by blocking the active sites of the metal surface, while HQS is a corrosion accelerator by activating the cathodic reaction. Changes of the impedance parameters in the electrochemical impedance spectroscopy(EIS) are related to the adsorption of 8HQ on the metal surface, which leads to the formation of a protective layer. The impedance diagram in the solution with HQS is similar to the one without additional organic compounds. The morphology and composition of the protective layer were studied by using SEM/EDS. The result confirms the function of the additions that the effect of 8HQ is due to the insoluble aluminum chelate, Al(HQ)3, to prevent adsorption of chloride ion, while the effect of HQS is to break down the oxide film.展开更多
文摘采用不同焊接压力对2060-T8铝锂合金进行了顶锻式摩擦塞补焊试验研究,分析了接头微观组织特征,第二相分布规律以及力学性能。结果表明:增大焊接压力可有效消除接头未焊合及孔洞缺陷。接头热影响区晶粒尺寸增大,热机械影响区及塞棒热机械影响区晶粒发生明显塑性变形,母材与塞棒之间产生了细小的等轴晶组织。接头不同区域较母材均发生软化,硬度最低值出现在塞棒热机械影响区,约为90 HV。当焊接压力为30 k N时,接头抗拉强度最高,达到378.9 MPa,断后伸长率为5.9%,接头系数为0.746。接头断裂方式为韧性断裂。
基金Beijing Natural Science Foundation (Grant No. 3194048)China Friction Stir Welding Center and to Beijing Key Laboratory of Pipeline Critical Technology and Equipment for Deepwater Oil & Gas Development (Grant No. BIPT2018006) for the financial support
文摘Friction stir welding was used to join two AA2060-T8 plates,and then the effect of precipitate evolution on microstructure and corrosion behavior of the joint was investigated.The evolution of precipitates on the top surface of the joint was characterized by scanning electron microscopy and transmission electron microscopy.The corrosion behaviors of different regions in the joint were investigated by an electrochemistry method and an alternating salt spray exposure.The corrosion was mainly dependent on the nature of precipitates in each region of the joint.The shoulder affected zone had the worst corrosion resistance as a result of the re-dissolved ofθ′(Al2Cu),T1(Al2CuLi)andδ′(Al3Li)phases,the formation of intergranular precipitates and precipitate-free zones.However,the thermomechanically affected zone had a slightly improved corrosion resistance because it had no intergranular precipitates.The heat affected zone and base metal had the best corrosion resistance.
基金Project(50571003) supported by the National Natural Science Foundation of China
文摘The corrosion behavior of aluminum alloy 2024-T3 was studied in 3.5% NaCl solution with two fluorescence quinoline compounds named 8-hydroxy-quinoline(8HQ) and 8-hydroxy-quinoline-5-sulfonic acid(HQS). The open circuit potential(OCP) test result indicates that both compounds change the alloy corrosion potential by adsorbing on the electrode surface. Polarization measurements show that 8HQ is a mixed type inhibitor by blocking the active sites of the metal surface, while HQS is a corrosion accelerator by activating the cathodic reaction. Changes of the impedance parameters in the electrochemical impedance spectroscopy(EIS) are related to the adsorption of 8HQ on the metal surface, which leads to the formation of a protective layer. The impedance diagram in the solution with HQS is similar to the one without additional organic compounds. The morphology and composition of the protective layer were studied by using SEM/EDS. The result confirms the function of the additions that the effect of 8HQ is due to the insoluble aluminum chelate, Al(HQ)3, to prevent adsorption of chloride ion, while the effect of HQS is to break down the oxide film.
