Abstract

In this work, a Mg–Zn–Ca magnesium matrix nanocomposite containing nano-sized TiC particles was firstly processed by multidirectional forging (MDF). With increasing the forging temperature from 230 to 310 °C for 1 MDF pass or the number of MDF passes at 270 °C, both volume fractions and average sizes of recrystallized grains increased. The average sizes of precipitated MgZn₂ phases increased with the increase in either the initial forging temperature or MDF passes, and the volume fractions gradually decreased with increasing the initial forging temperature or decreasing the MDF passes. With decreasing the initial MDF temperature, thermal expansion mismatch strengthening slightly decreased while fine-grain strengthening and Orowan strengthening gradually increased, resulting in a gradual increased yield strength. The elongation of the present nanocomposite gradually increased from 8.2% after 1 MDF pass to 22.7% after 6 MDF passes, while both yield strength and ultimate tensile strength did not change significantly. This could be ascribed to that although the fine-grain strengthening gradually reduced, there was no significant change in the Orowan strengthening caused by MgZn₂ phases with increasing the number of MDF passes.

Graphic abstract

中文翻译：

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多向锻造加工纳米TiCp/Mg-Zn-Ca镁基纳米复合材料的显微组织和抗拉强度

摘要

在这项工作中，首先通过多向锻造（MDF）加工含有纳米尺寸 TiC 颗粒的 Mg-Zn-Ca 镁基纳米复合材料。随着锻造温度从 230°C 增加到 310°C，1 个 MDF 道次或 MDF 道次在 270°C，再结晶晶粒的体积分数和平均尺寸均增加。析出MgZn ₂的平均粒径相随着初始锻造温度或 MDF 道次的增加而增加，而体积分数随着初始锻造温度的增加或 MDF 道次的减少而逐渐减少。随着MDF初始温度的降低，热膨胀失配强化略有下降，细晶强化和Orowan强化逐渐增强，屈服强度逐渐提高。本纳米复合材料的伸长率从 1 个 MDF 道次后的 8.2% 逐渐增加到 6 个 MDF 道次后的 22.7%，而屈服强度和极限拉伸强度都没有显着变化。这可以归因于虽然细晶强化逐渐减弱，但MgZn ₂引起的Orowan强化没有显着变化。 随着 MDF 传递次数的增加。

图形摘要