Abstracts

Heterogeneous structured materials achieve a combination of high strength and extreme ductility due to synergetic strengthening driven by conditions in the interfacial region. Although the origin of synergetic strengthening has been revealed to be strain incompatibility in the interfacial region, the effect of the strength difference between hard and soft phases on strengthening has not been investigated well. In the work reported in the present paper, the effect of the difference in strength of the hard and soft phases on synergetic strengthening was investigated by conducting in situ neutron diffraction tensile tests. As a result, it was determined that the dislocation density in a layered sheet of high Mn (HMn) steel/interstitial free (IF) steel is higher than that in a layered sheet of HMn/low carbon steel. The big difference in mechanical properties between HMn steel and IF steel induces a high stress gradient and results in additional dislocations. Because of the high dislocation density and large differences in mechanical property and anisotropy in the HMn/IF layered steel sheet, upper-bound rule-of-mixtures behavior occurs. Therefore, a great difference in the mechanical properties of hard and soft components increases the synergetic strengthening of heterogeneously structured materials.

Graphic Abstract

中文翻译：

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硬组分和软组分强度差异对层状材料协同增强的影响

摘要

由于界面区域条件的协同加强，异质结构材料实现了高强度和极好的延展性的结合。虽然协同加强的起源已被证明是在界面区域的应变不相容，但还没有很好地研究硬相和软相之间的强度差对加强的影响。在本文报道的工作中，通过进行原位中子衍射拉伸试验研究了硬相和软相强度差异对协同增强的影响。结果，确定高Mn（HMn）钢/无间隙（IF）钢的层板中的位错密度高于HMn /低碳钢的层状板中的位错密度。HMn钢和IF钢之间机械性能的巨大差异会引起较高的应力梯度，并导致其他位错。由于HMn / IF层状钢板的位错密度高，机械性能和各向异性的差异大，因此发生了上限混合规则行为。因此，硬组分和软组分的机械性能的巨大差异会增强异质结构材料的协同强化。

图形摘要