AZ31/Mg3Y composites with a layer thickness of 100–200 μm were fabricated by accumulated rolling bonding (ARB), which was followed by diffusion annealing at 300 °C for 0–32 h. An interface layer, containing numerous Al-Y precipitates, is formed in the Mg3Y layer that is adjacent to the interface as a result of Al diffusing from the AZ31 layers into the Mg3Y layers. The thickness of the interface layer gets increased and more precipitates are formed in the interface layer with the extension of the annealing time. The microhardness of the AZ31 and Mg3Y layer decreases firstly and then reaches a stable value, while the microhardness of the interface layer increases gradually with the extension of the annealing time. The AZ31/Mg3Y composites exhibit equivalent strength but increased ductility after diffusion annealing, in comparison to the as-rolled AZ31/Mg3Y composite. In addition, the AZ31/Mg3Y composites after annealing always present higher strength and ductility than AZ31/AZ31 composite, which was fabricated by the same process as that for the AZ31/Mg3Y composites. Hetero-deformation induced strengthening also plays an important role in the excellent strength and ductility of the annealed AZ31/Mg3Y composite. This study can provide a direction for improving the plasticity and strength of magnesium alloys synergistically.

通过累积轧制结合（ARB）制备层厚为100-200μm的AZ31/Mg3Y复合材料，然后在300℃下进行扩散退火0-32小时。由于 Al 从 AZ31 层扩散到 Mg3Y 层中，在邻近界面的 Mg3Y 层中形成了包含大量 Al-Y 沉淀物的界面层。随着退火时间的延长，界面层厚度增加，界面层中形成更多析出物。AZ31和Mg3Y层的显微硬度先下降然后达到稳定值，而界面层的显微硬度随着退火时间的延长逐渐增加。与轧制的 AZ31/Mg3Y 复合材料相比，AZ31/Mg3Y 复合材料在扩散退火后表现出相同的强度，但延展性有所提高。此外，退火后的AZ31/Mg3Y复合材料始终比采用与AZ31/Mg3Y复合材料相同的工艺制造的AZ31/AZ31复合材料表现出更高的强度和延展性。异形变形诱导强化对于退火 AZ31/Mg3Y 复合材料优异的强度和延展性也起着重要作用。该研究可为协同提高镁合金塑性和强度提供方向。