Thermo-plasticity of homogenized 7050 aluminum ingot was investigated by instantaneous tensile tests conducted at different temperatures. The results show that, with the increase of testing temperatures, the strength ...Thermo-plasticity of homogenized 7050 aluminum ingot was investigated by instantaneous tensile tests conducted at different temperatures. The results show that, with the increase of testing temperatures, the strength decreases, and the plasticity increases firstly and then decreases in homogenized 7050 ingot. When the studied alloy is deformed between 380℃ and 420℃, the deformation resistance is lower and plasticity is better. And the actual heating temperature for ingot before hot extrusion should be controlled between 360 ~C and 400 ~C. At low tensile temperatures, the deformation structure is mainly composed of dislocation substructure. With the increase of testing temperatures, transgranular fracture transforms into intergranular fracture progressively during deformation. At high tensile temperatures, the grain boundaries are weakened, deformation is concentrated at the grain boundaries and the re-orientation of equilibrium phases at grain boundaries appears.展开更多
A thermo-plastic/viscoplastic damage coupled model was formulated to describe the time independent and time dependent behaviors of geomaterials under temperature effect. The plastic strain was divided into instantaneo...A thermo-plastic/viscoplastic damage coupled model was formulated to describe the time independent and time dependent behaviors of geomaterials under temperature effect. The plastic strain was divided into instantaneous plastic strain and creep plastic strain. To take temperature effect into acconnt, a temperature variable was introduced into the instantaneous and creep plastic behavior descriptions and damage characterization, and a linear thermal expansion law was used in constitutive equation formulation. According to the mechanical behavior of rock salt, a specific model was proposed based on the previous model and applied to Avery rock salt, in which the numerical results obtained from our model had a good agreement with the data from experiments.展开更多
基金Project(JPPT-115-2-948) supported by the National Civilian Matched Program of China
文摘Thermo-plasticity of homogenized 7050 aluminum ingot was investigated by instantaneous tensile tests conducted at different temperatures. The results show that, with the increase of testing temperatures, the strength decreases, and the plasticity increases firstly and then decreases in homogenized 7050 ingot. When the studied alloy is deformed between 380℃ and 420℃, the deformation resistance is lower and plasticity is better. And the actual heating temperature for ingot before hot extrusion should be controlled between 360 ~C and 400 ~C. At low tensile temperatures, the deformation structure is mainly composed of dislocation substructure. With the increase of testing temperatures, transgranular fracture transforms into intergranular fracture progressively during deformation. At high tensile temperatures, the grain boundaries are weakened, deformation is concentrated at the grain boundaries and the re-orientation of equilibrium phases at grain boundaries appears.
基金Project supported by the National Natural Science Foundation of China(NSFC) (Nos. 10772190,50979104 and 51009132)
文摘A thermo-plastic/viscoplastic damage coupled model was formulated to describe the time independent and time dependent behaviors of geomaterials under temperature effect. The plastic strain was divided into instantaneous plastic strain and creep plastic strain. To take temperature effect into acconnt, a temperature variable was introduced into the instantaneous and creep plastic behavior descriptions and damage characterization, and a linear thermal expansion law was used in constitutive equation formulation. According to the mechanical behavior of rock salt, a specific model was proposed based on the previous model and applied to Avery rock salt, in which the numerical results obtained from our model had a good agreement with the data from experiments.
