In this work, microstructure and mechanical properties of Mg weld with addition of carbon nanotubes (CNTs) and TiC particles were investigated. The results showed that the weld microstructure was mainly presented as equiaxed grains with almost high angle grain boundaries. The introduction of reinforcements promoted the formation of precipitates and refined the grains effectively, the average grain size was refined by 51 % and 23 % with addition of CNTs and TiC particles, respectively. The dislocation density and the fraction of CSL boundaries were increased with addition of CNTs, while those were decreased with addition of TiC particles. Besides, the infrequent {10$\overline{1}$$\overline{1}$3} contraction twins formed within the weld due to the stress concentration caused by dislocation accumulation, which contributed to the Σ29 CSL boundary. The ultimate tensile strength and elongation rate were increased by 13.5 % and 40 % with addition of CNTs, while the ultimate tensile strength and micro-hardness were increased by 14.8 % and 20.9 % with addition of TiC particles.

中文翻译：

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添加 CNT 和 TiC 颗粒的镁焊缝的晶粒细化、孪晶形成和机械性能


在这项工作中，研究了添加碳纳米管 （CNT） 和 TiC 颗粒的 Mg 焊缝的微观结构和力学性能。结果表明，焊缝微观组织主要表现为等轴晶粒，晶界角度几乎很高。增强剂的引入促进了沉淀物的形成并有效地细化了晶粒，添加 CNTs 和 TiC 颗粒后，平均晶粒尺寸分别细化了 51 % 和 23 %。位错密度和 CSL 晶界分数随着 CNT 的添加而增加，而 TiC 颗粒的加入则降低。此外，不常见的 {10 1¯”由于$\stackrel{}{\mathrm{}}$位错积累引起的应力集中，焊缝内形成了 >1 ̄3} 收缩孪晶，这导致了 Σ29 CSL 边界。添加 CNT 后，极限拉伸强度和伸长率分别提高了 13.5 % 和 40 %，而添加 TiC 颗粒后，极限拉伸强度和显微硬度分别提高了 14.8 % 和 20.9 %。