To regulate the microstructure homogeneity of large aluminum structural forgings for aircraft,the surface cumulative plastic deformation was proposed.The microstructure of 7050 aluminum forgings after the surface cumu...To regulate the microstructure homogeneity of large aluminum structural forgings for aircraft,the surface cumulative plastic deformation was proposed.The microstructure of 7050 aluminum forgings after the surface cumulative plastic deformation was investigated by electron backscatter diffraction(EBSD),transmission electron microscopy(TEM),and X-ray diffraction(XRD).The results showed that the microstructure evolution of 7050 aluminum forgings was more sensitive to the deformation temperature than the strain rate.The dislocation density continued to increase with the decrease of the deformation temperature and the increase of the strain rate.Dislocation density and stored energy were accumulated by the surface cumulative plastic deformation.Besides,a static recrystallization(SRX)model of 7050 aluminum forgings was established.The SRX volume fraction calculated by this model was in good agreement with the experimental results,which indicated that the model could accurately describe the SRX behavior of 7050 aluminum forgings during the surface cumulative plastic deformation.展开更多
To model the cumulative deformation of granular soils under cyclic loading, a mathematical model was proposed. The power law connection between the shear strain and loading cycle was represented by using fractional de...To model the cumulative deformation of granular soils under cyclic loading, a mathematical model was proposed. The power law connection between the shear strain and loading cycle was represented by using fractional derivative approach. The volumetric strain was characterized by a modified cyclic flow rule which considered the effect of particle breakage. All model parameters were obtained by the cyclic and static triaxial tests. Predictions of the test results were provided to validate the proposed model. Comparison with an existing cumulative model was also made to show the advantage of the proposed model.展开更多
基金supported by the Natural Science Foundation of Hebei Province, China (No. E2019203075)the Top Young Talents Project of the Education Department of Hebei Province, China (No. BJ2019001)the State Key Laboratory Program of High Performance Complex Manufacturing, China (No. Kfkt2017-07)
文摘To regulate the microstructure homogeneity of large aluminum structural forgings for aircraft,the surface cumulative plastic deformation was proposed.The microstructure of 7050 aluminum forgings after the surface cumulative plastic deformation was investigated by electron backscatter diffraction(EBSD),transmission electron microscopy(TEM),and X-ray diffraction(XRD).The results showed that the microstructure evolution of 7050 aluminum forgings was more sensitive to the deformation temperature than the strain rate.The dislocation density continued to increase with the decrease of the deformation temperature and the increase of the strain rate.Dislocation density and stored energy were accumulated by the surface cumulative plastic deformation.Besides,a static recrystallization(SRX)model of 7050 aluminum forgings was established.The SRX volume fraction calculated by this model was in good agreement with the experimental results,which indicated that the model could accurately describe the SRX behavior of 7050 aluminum forgings during the surface cumulative plastic deformation.
基金Project supported by the National Natural Science Foundation of China(No.51509024)the Fundamental Research Funds for the Central Universities(No.106112015CDJXY200008)
文摘To model the cumulative deformation of granular soils under cyclic loading, a mathematical model was proposed. The power law connection between the shear strain and loading cycle was represented by using fractional derivative approach. The volumetric strain was characterized by a modified cyclic flow rule which considered the effect of particle breakage. All model parameters were obtained by the cyclic and static triaxial tests. Predictions of the test results were provided to validate the proposed model. Comparison with an existing cumulative model was also made to show the advantage of the proposed model.
