The fly ash cenosphere/AZ91D composites were successfully prepared and isothermally heat-treated at different tem- peratures for different time. The effects of semi-solid isothermal heat treatment on the microstructur...The fly ash cenosphere/AZ91D composites were successfully prepared and isothermally heat-treated at different tem- peratures for different time. The effects of semi-solid isothermal heat treatment on the microstructures and damping capacities of fly ash cenosphere/AZ91D composites were investigated. With the increase in isothermal temperature or holding time, the small liquid droplets within grains increased in size but decreased in quantity. The average size and shape factor of Mg2Si particles increased with the rise of isothermal temperature. The damping capacities of the composites were improved by isothermal heat treatment. At room temperature, the composites after heat treatment at 520 and 550 ℃ had a higher damping capacity due to interface damping when the strain amplitude was lower than about 8.8 × 10^-5, and the composite after heat treatment at 580 ℃ had a better damping capacity because of the dislocation damping under the condition of high strain amplitude. The damping capacities of the composites increased with the rise of the test temper- ature, and the damping mechanisms varied depending on different test temperatures. The interface damping played an important role when the test temperature was below about 100 ℃, and the dislocation damping and grain boundary damping took effect with the rise of test temperature.展开更多
基金supported by the Open Fund (No.OGE201702-07) of Key Laboratory of Oil and Gas Equipment,Ministry of Education (Southwest Petroleum University)the Key Research and Development Project of Shandong Province (No.2016GGX102041)+1 种基金the Natural Science Foundation of Shandong Province (No.ZR2017LEM004)the Fundamental Research Funds for the Central Universities of China (No.18CX02091A)
文摘The fly ash cenosphere/AZ91D composites were successfully prepared and isothermally heat-treated at different tem- peratures for different time. The effects of semi-solid isothermal heat treatment on the microstructures and damping capacities of fly ash cenosphere/AZ91D composites were investigated. With the increase in isothermal temperature or holding time, the small liquid droplets within grains increased in size but decreased in quantity. The average size and shape factor of Mg2Si particles increased with the rise of isothermal temperature. The damping capacities of the composites were improved by isothermal heat treatment. At room temperature, the composites after heat treatment at 520 and 550 ℃ had a higher damping capacity due to interface damping when the strain amplitude was lower than about 8.8 × 10^-5, and the composite after heat treatment at 580 ℃ had a better damping capacity because of the dislocation damping under the condition of high strain amplitude. The damping capacities of the composites increased with the rise of the test temper- ature, and the damping mechanisms varied depending on different test temperatures. The interface damping played an important role when the test temperature was below about 100 ℃, and the dislocation damping and grain boundary damping took effect with the rise of test temperature.
