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In this study, Si C/AA6061 composites with different Si C volume fractions(5%, 10%, 15% and 20%) were fabricated by spark plasma sintering. The deformation behaviour of the composites was studied by uniaxial compression test at temperatures from 573 K to 773 K and strain rates between 0.001 s(-)~1.and 1 s(-)~1..Results indicate that the flow stress of Si C/AA6061 composites increases with the increase of Si C volume fraction, with the decrease of deformation temperature and with the decrease of strain rate. The main deformation mechanism of the composites is dynamic recrystallisation(DRX), and the DRX degree depends on the processing parameters of deformation. Higher Si C volume fraction, higher deformation temperature and lower deformation strain rate promote the occurrence of DRX. The strain rate sensitivity and deformation activation energy of Si C/AA6061 composites are calculated. Results show that with the increase in deformation temperature and the decrease in Si C volume fraction, the strain rate sensitivity of the composites increases. From 573 K to 773 K, the average deformation activation energy of 5vol.%Si C/AA6061, 10 vol.%Si C/AA6061, 15 vol.%Si C/AA6061 and 20 vol.%Si C/AA6061 are 207.91, 230.88, 237.7 and249.87 k J mol(-)~1., respectively. The optimum hot working zone of the Si C/AA6061 composites is in the temperature range of 723 K to 773 K at strain rates from 0.1 s(-)~1.to 1 s(-)~1.
In this study, Si C / AA6061 composites with different Si C volume fractions (5%, 10%, 15% and 20%) were fabricated by spark plasma sintering. The deformation behavior of the composites was studied by uniaxial compression test at temperatures from 573 K to 773 K and strain rates between 0.001 s (-) ~ 1.and 1 s (-) ~ 1..Results indicate that the flow stress of Si C / AA6061 composites increases with the increase of Si C volume fraction, with the decrease of deformation temperature and with the decrease of strain rate. The main deformation mechanism of the composites is dynamic recrystallization (DRX), and the DRX degree depends on the processing parameters of deformation. Higher Si C volume fraction, higher deformation temperature and lower deformation strain rate promote the occurrence of DRX. The strain rate sensitivity and deformation activation energy of Si C / AA6061 composites were calculated. Results show that with the increase in deformation temperature and the decrease in Si C volume fractio % Si C / AA6061, 10 vol.% Si C / AA6061, 15 vol.% Si C / AA6061 and from 573 K to 773 K, the average deformation activation energy of 5 vol. The optimum hot working zone of the Si C / AA6061 composites is in the temperature range of 723 K to 20% C SiA / AA6061 are 207.91, 230.88, 237.7 and 249.87 k J mol (-) ~ 1, respectively. 773 K at strain rates from 0.1 s (-) ~ 1.to 1 s (-) ~ 1.