Al-Mg-Si合金押出材の再結晶組織に及ぼす押出温度の影響

摘要

A study was made to determine the effect of the extrusion temperature on the recrystallized grain size and texture of an AA6005C alloy. Several extrusion tests were conducted at temperatures from 753 to 793K at an extrusion speed of 3m/min. A decrease in extrusion temperature from 793K to 753K was found to increase the average size of recrystallized grains from 170μm to 230μm and the volume fraction of cube-oriented recrystallized grains from 30％ to 40％. A high-temperature compression test, conducted to elucidate the formation process of recrystallized grains, revealed that, compared with the extrusion at 793K, the one at 753K yields fewer recrystallized grains immediately after the deformation, indicating that a larger amount of energy is stored in the unrecrystallized region. The increased stored energy is considered to have promoted the preferential growth of the recrystallized Cube grains.