The evolution of texture during the annealing and hot rolling process of extruded AZ31 magnesium alloy sheets was studied. There are two kinds of texture components in the extruded AZ31 sheets. One is {0002}<1010&g...The evolution of texture during the annealing and hot rolling process of extruded AZ31 magnesium alloy sheets was studied. There are two kinds of texture components in the extruded AZ31 sheets. One is {0002}<1010> and the other is {1010}<1120>. The {0002}<1010>component predominates. After annealing at 723 K for 3 h, both {0002}<1010> and {1010}<1120> components are strengthened moderately. This indicates that grains with both two components mentioned above grow faster than those with other orientations. The {1010}<1120> component disappears and the intensity of {0002}<1010> component decreases significantly after hot rolling with a 30% reduction at 623 K. This is mainly attributed to rotational dynamic recrystallization (RDX) during the hot rolling.展开更多
Cerium was added in AZ31 alloy with the contents of 0.4%,0.8%and 1.2%respectively to produce experimental alloys. The grain refinement of Ce in the as-cast and rolled AZ31 alloy were studied by using Polyvar-MET optic...Cerium was added in AZ31 alloy with the contents of 0.4%,0.8%and 1.2%respectively to produce experimental alloys. The grain refinement of Ce in the as-cast and rolled AZ31 alloy were studied by using Polyvar-MET optical microscope with a VSM2000 quantitative analysis system,KYKY2000 SEM and Tecnai G^2 20 TEM.And the mechanical properties of AZ31+Ce alloy were tested on a CSS-44100 testing system with computerized data acquisition.The results show that the cerium has a good grain refinement effect on the as-cast AZ31 alloy because cerium can build up a solute enriched zone rapidly during the solidification process.The dynamic recrystallization(DRX) grains less than 10μm can be obtained in hot rolled AZ31+Ce alloy.A cold rolling deformation degree over than 20%and a following annealing at 400℃for 1 h will lead to refine and uniform grains with the sizes of about 25μm.The cerium can form dispersed and thermally stable Al_4Ce phase that can prohibit the coarsening of grains in AZ31+Ce alloy during the hot rolling and annealing process.展开更多
The hot deformation simulation of a ZK60 magnesiuln alloy at different temperatures from 373 to 673 K and different strain rates of 0.1, 0.01 and 0.002 s^-1 was studied by using the Gleebe-1500 simulator. The plastic ...The hot deformation simulation of a ZK60 magnesiuln alloy at different temperatures from 373 to 673 K and different strain rates of 0.1, 0.01 and 0.002 s^-1 was studied by using the Gleebe-1500 simulator. The plastic deformation behavior was measured and the deformation activation energy was calculated. The microstructures of ZK60 magnesium alloy with an addition of neodymium during the deformation process were observed by using Polyvar-MET optical microscope and Tecnai G^2 20 TEM. The results show that the working hardening, the dynamic recovery and the dynamic recrystallization occur during the plastic deformation process at different temperatures and strain rates. The dynamic recrystallization starts when the temperature is over 473 K and the DRX grain size after hot deformation is only 5-10 μm. So the refined grains improve both the tensile strength and the elongation of alloys at room temperature. Neodymium is added into the alloy and a precipitate phase Mg12Nd that impedes the movement of dislocations is formed, which benefits to increasing mechanical properties of ZK60 magnesium alloy.展开更多
基金Project(2006 BAE04B02-3) supported by the National Scientific and Technological Support Program during the 11th Five-year Plan of China
文摘The evolution of texture during the annealing and hot rolling process of extruded AZ31 magnesium alloy sheets was studied. There are two kinds of texture components in the extruded AZ31 sheets. One is {0002}<1010> and the other is {1010}<1120>. The {0002}<1010>component predominates. After annealing at 723 K for 3 h, both {0002}<1010> and {1010}<1120> components are strengthened moderately. This indicates that grains with both two components mentioned above grow faster than those with other orientations. The {1010}<1120> component disappears and the intensity of {0002}<1010> component decreases significantly after hot rolling with a 30% reduction at 623 K. This is mainly attributed to rotational dynamic recrystallization (RDX) during the hot rolling.
基金Project(2006BAE04B02-3)supported by the National Science and Technology Support Program during the 11th Five-Year Plan of China
文摘Cerium was added in AZ31 alloy with the contents of 0.4%,0.8%and 1.2%respectively to produce experimental alloys. The grain refinement of Ce in the as-cast and rolled AZ31 alloy were studied by using Polyvar-MET optical microscope with a VSM2000 quantitative analysis system,KYKY2000 SEM and Tecnai G^2 20 TEM.And the mechanical properties of AZ31+Ce alloy were tested on a CSS-44100 testing system with computerized data acquisition.The results show that the cerium has a good grain refinement effect on the as-cast AZ31 alloy because cerium can build up a solute enriched zone rapidly during the solidification process.The dynamic recrystallization(DRX) grains less than 10μm can be obtained in hot rolled AZ31+Ce alloy.A cold rolling deformation degree over than 20%and a following annealing at 400℃for 1 h will lead to refine and uniform grains with the sizes of about 25μm.The cerium can form dispersed and thermally stable Al_4Ce phase that can prohibit the coarsening of grains in AZ31+Ce alloy during the hot rolling and annealing process.
基金Project(2006BAE04B02-3)supported by the National Key Program of 11th Five-Year Plan of China
文摘The hot deformation simulation of a ZK60 magnesiuln alloy at different temperatures from 373 to 673 K and different strain rates of 0.1, 0.01 and 0.002 s^-1 was studied by using the Gleebe-1500 simulator. The plastic deformation behavior was measured and the deformation activation energy was calculated. The microstructures of ZK60 magnesium alloy with an addition of neodymium during the deformation process were observed by using Polyvar-MET optical microscope and Tecnai G^2 20 TEM. The results show that the working hardening, the dynamic recovery and the dynamic recrystallization occur during the plastic deformation process at different temperatures and strain rates. The dynamic recrystallization starts when the temperature is over 473 K and the DRX grain size after hot deformation is only 5-10 μm. So the refined grains improve both the tensile strength and the elongation of alloys at room temperature. Neodymium is added into the alloy and a precipitate phase Mg12Nd that impedes the movement of dislocations is formed, which benefits to increasing mechanical properties of ZK60 magnesium alloy.
