A grain structure tailoring strategy was implemented by powder assembly & alloying in carbon nanotube reinforced Al-Cu-Mg composites. Tensile tests revealed that composites with trimodal grain structure had an outstanding combination of strength and ductility, surpassing that of composites with simpler grain structures (e.g. bimodal and unimodal structure). An in-situ tracking of the strain distributions and computational simulations were jointly employed to provide insight into the underlying mechanisms. The results unravel that the trimodal grain structure is more prone to facilitate strain hardening and alleviate strain/stress concentrations, thereby rendering the composites high yield strength and large tensile ductility.

IMPACT STATEMENT

A novel trimodal grain structure was designed for the first time to achieve an excellent strength-ductility combination in CNT/Al-Cu-Mg composites.

通过粉末组装和合金化在碳纳米管增强的Al-Cu-Mg复合材料中实施了晶粒结构定制策略。拉伸试验表明，具有三峰模态结构的复合材料具有出色的强度和延展性组合，超过了具有更简单的晶粒结构（如双峰和单峰结构）的复合材料。一个原位的应变分布和计算模拟的跟踪被共同用来提供深入了解的基本机制。结果表明三峰晶粒结构更易于促进应变硬化并减轻应变/应力集中，从而使复合材料具有较高的屈服强度和较大的延展性。

影响陈述

首次设计了新颖的三峰晶粒结构，以在CNT / Al-Cu-Mg复合材料中实现出色的强度-延展性组合。