The effect of quenching rate on the electrical conductivity and microstructure of thick plates of incumbent AA7050 was investigated by employing Jominy end quench test. The electrical conductivity measurement and micr...The effect of quenching rate on the electrical conductivity and microstructure of thick plates of incumbent AA7050 was investigated by employing Jominy end quench test. The electrical conductivity measurement and microstructural observation were conducted at different distances from the quenched end. The results indicate that the average cooling rates decrease with increasing the distance from the quenched end of the bar in the quench sensitive temperature range. However, the electrical conductivity increases with the increase of distance from the quenched end. The surface parts of the plate were fully recrystallized, while partial recrystallization took place at the quarter and center parts of the plate. The quench induced grain boundary precipitates became remarkably coarser and discontinuously distributed with increasing distance from the quenched end of the bar. Plenty of heterogeneous precipitates were observed to nucleate on A13Zr dispersoids when the distance from the quenched end was greater than 38mm.展开更多
The influence of pre-deformation on aging precipitates of three near peak-aged Al–Cu–Li alloys,1460 alloy with a low Cu/Li ratio（1.46）,2050 alloy with a high Cu/Li ratio（4.51） and 2A96 alloy with a medium Cu/Li ...The influence of pre-deformation on aging precipitates of three near peak-aged Al–Cu–Li alloys,1460 alloy with a low Cu/Li ratio（1.46）,2050 alloy with a high Cu/Li ratio（4.51） and 2A96 alloy with a medium Cu/Li ratio（2.97）,was investigated.The strength of the aged alloys is enhanced by the pre-deformation.The effectiveness of pre-deformation on precipitates is dependent on the alloy＇s composition.With increasing the pre-deformation,the population density of T1（Al2Cu Li） precipitates increases in all three Al–Cu–Li alloys and their diameter decreases in 2050 and 2A96 alloys,and the greatest effectiveness is observed in 2A96 alloy.The pre-deformation also increases the population density of θ＇（Al2Cu）precipitates and decreases their diameter in 2050 and 2A96 Al–Li alloys,but the effectiveness is smaller compared to that on T1 precipitates.In 1460 alloy subjected to two-step aging at 130 ℃ for 20 h followed by 160 ℃ for 12 h,the main precipitates are δ＇（Al3Li）.At 2%–6% pre-deformation,GP-I zones form and pre-deformation displays little influence.Eight percentage pre-deformation promotes θ＇＇/θ＇ precipitation and increases their population density.展开更多
基金Project (50904010) supported by the National Natural Science Foundation of ChinaProject (2010DFB50340) supported by the China International Science and Technology Cooperation
文摘The effect of quenching rate on the electrical conductivity and microstructure of thick plates of incumbent AA7050 was investigated by employing Jominy end quench test. The electrical conductivity measurement and microstructural observation were conducted at different distances from the quenched end. The results indicate that the average cooling rates decrease with increasing the distance from the quenched end of the bar in the quench sensitive temperature range. However, the electrical conductivity increases with the increase of distance from the quenched end. The surface parts of the plate were fully recrystallized, while partial recrystallization took place at the quarter and center parts of the plate. The quench induced grain boundary precipitates became remarkably coarser and discontinuously distributed with increasing distance from the quenched end of the bar. Plenty of heterogeneous precipitates were observed to nucleate on A13Zr dispersoids when the distance from the quenched end was greater than 38mm.
基金the National High Technology Research and Development Program of China(No.2013AA032401)Teacher’s Research Foundation of Central South University(No.2013JSJJ 001) for the financial supportNonferrous Metal Oriented Advanced Structural Materials and Manufacturing Cooperative Innovation Centre
文摘The influence of pre-deformation on aging precipitates of three near peak-aged Al–Cu–Li alloys,1460 alloy with a low Cu/Li ratio（1.46）,2050 alloy with a high Cu/Li ratio（4.51） and 2A96 alloy with a medium Cu/Li ratio（2.97）,was investigated.The strength of the aged alloys is enhanced by the pre-deformation.The effectiveness of pre-deformation on precipitates is dependent on the alloy＇s composition.With increasing the pre-deformation,the population density of T1（Al2Cu Li） precipitates increases in all three Al–Cu–Li alloys and their diameter decreases in 2050 and 2A96 alloys,and the greatest effectiveness is observed in 2A96 alloy.The pre-deformation also increases the population density of θ＇（Al2Cu）precipitates and decreases their diameter in 2050 and 2A96 Al–Li alloys,but the effectiveness is smaller compared to that on T1 precipitates.In 1460 alloy subjected to two-step aging at 130 ℃ for 20 h followed by 160 ℃ for 12 h,the main precipitates are δ＇（Al3Li）.At 2%–6% pre-deformation,GP-I zones form and pre-deformation displays little influence.Eight percentage pre-deformation promotes θ＇＇/θ＇ precipitation and increases their population density.
