Al_2O_3/Cu复合材料强化机理研究

Investigation on Strengthened Mechanism of Al_2O_3/Cu Composite

采用内氧化法制备了Al2O3/Cu复合材料,进行了高温电子拉伸实验,并通过微观组织观察,分析了该复合材料的强化机理。拉伸实验结果显示:Al2O3/Cu复合材料不仅室温强度很高,而且高温时仍保持较高的强度。微观组织观察分析表明:细小的Al2O3颗粒的弥散分布是该复合材料具有高强度的主要原因,表现在:Al2O3颗粒存在能够抑制Cu基再结晶的进行;Al2O3颗粒的存在阻碍晶界亚晶界运动,从而阻碍晶粒长大;Al2O3颗粒的阻碍位错运动,增加位错密度;Al2O3颗粒的存在提高材料的蠕变抗力。

The strengthened mechanism of Al 2O 3/Cu composite fabricated by internal oxidation was investigated by microstructure observation after electric tensile experiment in elevated temperatures. The results of tensile experiment show that the strength of Al 2O 3/Cu composite is not only high at room temperature but keeps well in elevated temperatures. The study on microstructure reveal that the strengthening of Al 2O 3/Cu composite is mainly attributed to the disperse of the nano scale of alumina particles which can hamper the copper matrix recrystallization, restrain the mobility of grain boundary and sub grain boundary therefore hinder grain growth, restrict the mobility of the dislocations which increase the density of dislocation , and improve creep strength of the composite.