Deformation Behavior of 7075Al/SICP Composite During Multi- Pass Deformation at High temperatures

摘要

Hot deformation behavior of 7075 aluminum alloy containing 15 vol % of SiC particles (average size of 14 micron) and the monolithic alloy was studied at 300 and 400°C at constant strain rate of ls~(-1) under uniaxial compression. The results showed that the fractional softening (FS) increased in both reinforced and monolithic alloys when the deformation temperature increased from 300 to 400°C, but monolithic alloy showed a slightly higher FS compared to composite under identical deformation conditions. TEM examination revealed that the monolithic alloy and composite contained almost similar substructures after either single or double pass deformation at a given temperature irrespective of interpass hold time. Subgrain growth was observed in these materials during holding after deformation at 400°C, but such grain growth did not occur at 300°C. The structural study showed that static recrystallization did not occur in these materials during hold time between passes, and the fractional softening occurs mainly due to static recovery.