Martensitic transformation behavior was studied for zirconia containing 4%～10% CeO2 (in mole fraction) by using a dilatometric method. The Ms (Martensite start temperature) decreased near linearly with increasing CeO...Martensitic transformation behavior was studied for zirconia containing 4%～10% CeO2 (in mole fraction) by using a dilatometric method. The Ms (Martensite start temperature) decreased near linearly with increasing CeO2. Different transformation modes were observed depending on the composition and cooling rate. ZrO2 containing 6% CeO2 showed isothermal transformation behavior, whereas ZrO2 containing 9% and 10% CeO2 showed athermal transformation behavior. However, ZrO2 containing 8% CeO2 showed either isothermal or athermal transformations behavior depending on the cooling rate. A TTT (Time-Temperature-Transformation) diagram was proposed for ZrO2 containing 8% CeO2.展开更多
This work investigated the response of Cu46Zr42Al7Y5 glass ribbons to both dynamic and static heating using differential scanning calorimeter （DSC）. The DSC curve manifests three exothermic responses to dynamic heat...This work investigated the response of Cu46Zr42Al7Y5 glass ribbons to both dynamic and static heating using differential scanning calorimeter （DSC）. The DSC curve manifests three exothermic responses to dynamic heating, among which the first and the third one are the signatures of the normal sub-Tg （Tg, glass transition temperature） relaxation and the crystallization process, respectively. The second one is attributed to a partial overlap between the endothermic response to the glass transition and the exothermic response to the formation of ordered clusters. The cluster ordering, which begins at the final stage of glass transition, has been verified by the differences in the activation energy of the sub-Tg relax- ation, the cluster ordering and primary crystallization for both the as-spun and annealed ribbons. The cluster ordering could be driven by the large difference between the Zr-Y mixing enthalpy and the Al-Y （or Cu-Y） mixing enthalpy. The findings contribute to distinguishing between phase separation and clusters motion scenarios.展开更多
文摘Martensitic transformation behavior was studied for zirconia containing 4%～10% CeO2 (in mole fraction) by using a dilatometric method. The Ms (Martensite start temperature) decreased near linearly with increasing CeO2. Different transformation modes were observed depending on the composition and cooling rate. ZrO2 containing 6% CeO2 showed isothermal transformation behavior, whereas ZrO2 containing 9% and 10% CeO2 showed athermal transformation behavior. However, ZrO2 containing 8% CeO2 showed either isothermal or athermal transformations behavior depending on the cooling rate. A TTT (Time-Temperature-Transformation) diagram was proposed for ZrO2 containing 8% CeO2.
基金supported by the National Natural Science Foundation of China(5117109051571131)the Fundamental Research Funds of Shandong University(2014YQ008)
文摘This work investigated the response of Cu46Zr42Al7Y5 glass ribbons to both dynamic and static heating using differential scanning calorimeter （DSC）. The DSC curve manifests three exothermic responses to dynamic heating, among which the first and the third one are the signatures of the normal sub-Tg （Tg, glass transition temperature） relaxation and the crystallization process, respectively. The second one is attributed to a partial overlap between the endothermic response to the glass transition and the exothermic response to the formation of ordered clusters. The cluster ordering, which begins at the final stage of glass transition, has been verified by the differences in the activation energy of the sub-Tg relax- ation, the cluster ordering and primary crystallization for both the as-spun and annealed ribbons. The cluster ordering could be driven by the large difference between the Zr-Y mixing enthalpy and the Al-Y （or Cu-Y） mixing enthalpy. The findings contribute to distinguishing between phase separation and clusters motion scenarios.
