Warm tensile tests for aluminum alloy 7022 sheet are held at different temperatures and strain rates. The range of temperature is 293-773 K and that of the strain rate is 0. 001-0.1 s^-1. The warm tensile properties,r...Warm tensile tests for aluminum alloy 7022 sheet are held at different temperatures and strain rates. The range of temperature is 293-773 K and that of the strain rate is 0. 001-0.1 s^-1. The warm tensile properties,relations among temperature,strain rate,and the flow stress are discussed. Constitutive equations under the warm tension are obtained based on revised Hooke law and Grosman equation. It is concluded that flow stress declines with the increase of the temperature and the decrease of the strain rates. The elongation percentage increases with the increase of the temperature and the decrease of strain rate.展开更多
The thermomechanical behavior of precipitation-hardened aluminum alloy AA7022-T6 was studied using isothermal compression at temperatures of 623−773 K and strain rates of 0.01−1 s^−1.The experimental results indicated...The thermomechanical behavior of precipitation-hardened aluminum alloy AA7022-T6 was studied using isothermal compression at temperatures of 623−773 K and strain rates of 0.01−1 s^−1.The experimental results indicated that dynamic recrystallization(DRX)is a predominant hot deformation mechanism,especially at elevated temperatures and low strain rates.The modified Johnson−Cook(J−C)and the strain compensated Arrhenius-type models were developed to predict the hot flow behavior under different deformation conditions.The correlation coefficients of modified J−C model and the strain compensated Arrhenius-type models were 0.9914 and 0.9972,respectively,their average relative errors(ARE)were 6.074%and 4.465%,respectively,and their root mean square errors(RMSE)were 10.611 and 1.665 MPa,respectively,indicating that the strain compensated Arrhenius-type model can predict the hot flow stress of AA7022-T6 aluminum alloy with an appropriate accuracy.展开更多
The Hopkinson pressure bar tests for base metal and friction stir jointing ( FSJ ) jointed region of 7022aluminum alloy are carried out at different temperatures and strain rates.The temperature is 30 - 400°C and...The Hopkinson pressure bar tests for base metal and friction stir jointing ( FSJ ) jointed region of 7022aluminum alloy are carried out at different temperatures and strain rates.The temperature is 30 - 400°C and the strain rate is 1 200 - 5 000s -1 .High strain rate for base metal and FSJ jointed region of 7022aluminum alloy are studied.The corresponding stress-strain curves are obtained.The results show that the flow stresses of base metal and FSJ jointed region of 7022aluminum alloy decline with the increase of temperature and increase with the increase of strain rate.Furthermore , the constitutive equation for base metal and FSJ jointed region of 7022aluminum alloy at high temperature and high strain rate is obtained based on Johnson-Cook model.展开更多
基金Supported by the National Natural Science Foundation of China (50772095)the Graduate Innovation Foundation of Jiangsu Province (CX09B-073Z)~~
文摘Warm tensile tests for aluminum alloy 7022 sheet are held at different temperatures and strain rates. The range of temperature is 293-773 K and that of the strain rate is 0. 001-0.1 s^-1. The warm tensile properties,relations among temperature,strain rate,and the flow stress are discussed. Constitutive equations under the warm tension are obtained based on revised Hooke law and Grosman equation. It is concluded that flow stress declines with the increase of the temperature and the decrease of the strain rates. The elongation percentage increases with the increase of the temperature and the decrease of strain rate.
文摘The thermomechanical behavior of precipitation-hardened aluminum alloy AA7022-T6 was studied using isothermal compression at temperatures of 623−773 K and strain rates of 0.01−1 s^−1.The experimental results indicated that dynamic recrystallization(DRX)is a predominant hot deformation mechanism,especially at elevated temperatures and low strain rates.The modified Johnson−Cook(J−C)and the strain compensated Arrhenius-type models were developed to predict the hot flow behavior under different deformation conditions.The correlation coefficients of modified J−C model and the strain compensated Arrhenius-type models were 0.9914 and 0.9972,respectively,their average relative errors(ARE)were 6.074%and 4.465%,respectively,and their root mean square errors(RMSE)were 10.611 and 1.665 MPa,respectively,indicating that the strain compensated Arrhenius-type model can predict the hot flow stress of AA7022-T6 aluminum alloy with an appropriate accuracy.
基金Supported by the National Natural Science Foundation of China(51175255)the University Natural Science Foundation of Anhui Province(KJ2012Z388)the Scientific Research Starting Foundation for Talent of Huang-shan University(2012xkjq001)
文摘The Hopkinson pressure bar tests for base metal and friction stir jointing ( FSJ ) jointed region of 7022aluminum alloy are carried out at different temperatures and strain rates.The temperature is 30 - 400°C and the strain rate is 1 200 - 5 000s -1 .High strain rate for base metal and FSJ jointed region of 7022aluminum alloy are studied.The corresponding stress-strain curves are obtained.The results show that the flow stresses of base metal and FSJ jointed region of 7022aluminum alloy decline with the increase of temperature and increase with the increase of strain rate.Furthermore , the constitutive equation for base metal and FSJ jointed region of 7022aluminum alloy at high temperature and high strain rate is obtained based on Johnson-Cook model.
