Using the Gleeble-1500 D simulator, the hot deformation behavior and dynamic recrystallization critical conditions of the 10%Ti C/Cu-Al2O3(volume fraction) composite were investigated by compression tests at the tempe...Using the Gleeble-1500 D simulator, the hot deformation behavior and dynamic recrystallization critical conditions of the 10%Ti C/Cu-Al2O3(volume fraction) composite were investigated by compression tests at the temperatures from 450 °C to 850 °C with the strain rates from 0.001 s-1 to 1 s-1. The results show that the softening mechanism of the dynamic recrystallization is a feature of high-temperature flow true stress-strain curves of the composite, and the peak stress increases with the decreasing deformation temperature or the increasing strain rate. The thermal deformation activation energy was calculated as 170.732 k J/mol and the constitutive equation was established. The inflection point in the lnθ-ε curve appears and the minimum value of-(lnθ)/ε-ε curve is presented when the critical state is attained for this composite. The critical strain increases with the increasing strain rate or the decreasing deformation temperature. There is linear relationship between critical strain and peak strain, i.e., εc=0.572εp. The predicting model of critical strain is described by the function of εc=1.062×10-2Z0.0826.展开更多
The performance of Al-Ti-C master alloy in refining Al-10Mg and Al-5Cu alloys was studied by using electron probe micro-analyzer （EPMA） and X-ray diffractometer （XRD） analysis. The results indicate that there are ...The performance of Al-Ti-C master alloy in refining Al-10Mg and Al-5Cu alloys was studied by using electron probe micro-analyzer （EPMA） and X-ray diffractometer （XRD） analysis. The results indicate that there are obvious fading phenomena in both Al-10Mg and Al-5Cu alloys with the addition of Al-5Ti-0.4C refiner which contains TiC and TiAl3 compounds. Mg element has no influence on the stability of TiC and TiAl3, while TiC particles in Al-10Mg alloy react with Al to form Al4C3 particles, resulting in the refinement fading. However, TiC particles are relatively stable in Al-5Cu alloy, while TiAl3 phase reacts with Al2Cu to produce a new phase Ti（Al, Cu）2, which is responsible for the refinement fading in Al-5Cu alloy. These indicate that the refinement fading will not occur only when both the TiC particles and TiAl3 compound of Al-Ti-C refiner are stable in Al alloys.展开更多
The formation of the new bulk amorphous Zr Ti Cu Ni Be C alloy with high strength is reported. The effects of the small size atoms on the glass forming ability, strength and thermal stability of the amorphous alloy ar...The formation of the new bulk amorphous Zr Ti Cu Ni Be C alloy with high strength is reported. The effects of the small size atoms on the glass forming ability, strength and thermal stability of the amorphous alloy are investigated. The formation mechanism of the bulk amorphous alloy is discussed.展开更多
基金Project(51101052) supported by the National Natural Science Foundation of China
文摘Using the Gleeble-1500 D simulator, the hot deformation behavior and dynamic recrystallization critical conditions of the 10%Ti C/Cu-Al2O3(volume fraction) composite were investigated by compression tests at the temperatures from 450 °C to 850 °C with the strain rates from 0.001 s-1 to 1 s-1. The results show that the softening mechanism of the dynamic recrystallization is a feature of high-temperature flow true stress-strain curves of the composite, and the peak stress increases with the decreasing deformation temperature or the increasing strain rate. The thermal deformation activation energy was calculated as 170.732 k J/mol and the constitutive equation was established. The inflection point in the lnθ-ε curve appears and the minimum value of-(lnθ)/ε-ε curve is presented when the critical state is attained for this composite. The critical strain increases with the increasing strain rate or the decreasing deformation temperature. There is linear relationship between critical strain and peak strain, i.e., εc=0.572εp. The predicting model of critical strain is described by the function of εc=1.062×10-2Z0.0826.
基金This work was financially supported by the National Natural Science Foundation of China (No.50171037).
文摘The performance of Al-Ti-C master alloy in refining Al-10Mg and Al-5Cu alloys was studied by using electron probe micro-analyzer （EPMA） and X-ray diffractometer （XRD） analysis. The results indicate that there are obvious fading phenomena in both Al-10Mg and Al-5Cu alloys with the addition of Al-5Ti-0.4C refiner which contains TiC and TiAl3 compounds. Mg element has no influence on the stability of TiC and TiAl3, while TiC particles in Al-10Mg alloy react with Al to form Al4C3 particles, resulting in the refinement fading. However, TiC particles are relatively stable in Al-5Cu alloy, while TiAl3 phase reacts with Al2Cu to produce a new phase Ti（Al, Cu）2, which is responsible for the refinement fading in Al-5Cu alloy. These indicate that the refinement fading will not occur only when both the TiC particles and TiAl3 compound of Al-Ti-C refiner are stable in Al alloys.
基金grateful to the financial support of the Alexander von Humboldt Foundation
文摘The formation of the new bulk amorphous Zr Ti Cu Ni Be C alloy with high strength is reported. The effects of the small size atoms on the glass forming ability, strength and thermal stability of the amorphous alloy are investigated. The formation mechanism of the bulk amorphous alloy is discussed.
