中文摘要：

AP65镁合金具有较强的放电活性,是一种极具吸引力的大功率海水激活电池用阳极材料.应用于电池阳极的AP65板带材通常采用热挤压等塑性变形方式制备,因而挤压比显著影响AP65的显微组织和放电行为.采用电化学方法结合显微组织表征系统研究不同挤压比（8.2∶1,12.3∶1和24.5∶1）对AP65放电行为的影响,结果表明：当挤压比为12.3∶1时,AP65具有细小而均匀的晶粒尺寸、破碎的第二相Al8Mn5和较低的位错密度.这一显微组织模式导致AP65带材拥有较负的放电电位（-1.780V vs.SCE）和较高的阳极利用率（（87.7±0.2）%）.因此,在450°C下以0.05 m/s的速度热挤压时,随挤压比增大,AP65镁合金的电化学性能先提高后降低,在挤压比12.3∶1附近AP65镁阳极达到较好放电性能.

英文摘要：

AP65 magnesium alloy is an attractive candidate for the anode of higher-power seawater activated battery because of its strong discharge activity. In practical applications, plastic forming such as hot extrusion is usually adopted to fabricate the AP65 sheets for serving as the battery anodes. Thus, the extrusion ratio obviously affects the micro structure and discharge behavior of AP65. The effect of different extrusion ratios （8.2-1, 12.3-1 and 24.5-1） on the discharge behavior and microstructure of AP65 were systematically investigated. The results indicate that the sample with the extrusion ratio of 12.3-1 has uniformly refined grains, low density of dislocations, and fractured A18Mn5 phase, thus leading to more negative discharge potential （-1.780 Y vs. SCE） and higher anodic efficiency （87.7±0.2） % ） than other extruded samples. Therefore, the electrochemical performance of AP65 rises first and then declines as the extrusion ratio increases with the extrusion speed of 0.05 m/s at 450°C, and the discharge properties achieve the optimal value when the extrusion ratio is close to 12.3：1.