Isothermal hot compression at the temperature range of 573–698 K and strain rates of 0.005–1.0 s⁻¹ was used to investigate the flow behavior and processing characteristics of the nano-SiCp/AZ91 composites. Effects of the incorporated particles and their particulate size on the workability of the base alloy were then compared and discussed. Results show that compared with the monolithic AZ91 alloy, the incorporated nano-SiC particles effectively increase the flow stress of the composites by blocking the strain-induced dislocations, while effect of the micro-SiC particles varies due to the competition between pinning effect and particle stimulating nucleation (PSN) mechanism. Three domains of peak energy dissipation efficiency are identified in the processing map and the corresponding microstructures examined by EBSD indicate that continuous dynamic recrystallization (DRX) occurs during the compression. The instability characteristics at low temperature are severe mechanical twinning and micro-cracks, while that at high temperature is intergranular cracking. The incorporation of SiC particles enhances the high temperature (>655 K) workability of AZ91 by increasing the upper limit of the processing strain rate and enables low temperature processing by decreasing the lower limit of the temperature. However, the added particles impose a side effect by enlarging the instability domain of the base alloy to a lower strain rate and even higher temperature.

等温热压缩，温度范围为573–698 K，应变速率为0.005–1.0 s ^-1用于研究纳米SiCp / AZ91复合材料的流动行为和加工特性。然后比较并讨论了掺入的颗粒及其颗粒尺寸对基础合金可加工性的影响。结果表明，与单块AZ91合金相比，掺入的纳米SiC颗粒通过阻止应变诱发的位错有效地增加了复合材料的流动应力，而微SiC颗粒的作用则由于钉扎效应与颗粒之间的竞争而发生了变化。刺激成核（PSN）机制。在加工图中确定了峰值能量耗散效率的三个域，并且由EBSD检查的相应微结构表明在压缩过程中发生了连续动态重结晶（DRX）。低温下的不稳定性特征是严重的机械孪晶和微裂纹，而高温下的不稳定性特征是晶间裂纹。SiC颗粒的掺入通过增加加工应变率的上限来提高AZ91的高温（> 655 K）可加工性，并通过降低温度的下限来进行低温加工。然而，添加的颗粒通过将基础合金的不稳定性域扩大到较低的应变速率甚至更高的温度而施加了副作用。655 K）通过增加加工应变率的上限来提高AZ91的可加工性，并通过降低温度下限来实现低温加工。然而，添加的颗粒通过将基础合金的不稳定性域扩大到较低的应变速率甚至更高的温度而施加了副作用。655 K）通过增加加工应变率的上限来提高AZ91的可加工性，并通过降低温度下限来实现低温加工。然而，添加的颗粒通过将基础合金的不稳定性域扩大到较低的应变速率甚至更高的温度而施加了副作用。