Wu Guangshan, Li Yangqi, Chen Fei
Department of Plasticity Technology, National Engineering Research Center of Die and Mold CAD, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China.
Materials (Basel). 2021 Sep 1;14(17):5001. doi: 10.3390/ma14175001.
Bimodal grain structure leads to high strength and strain hardening effect of metallic materials. In this study, an effective approach called flow control extrusion (FCE) is proposed to achieve heterostructures of pure copper. Compared with conventional extrusion (CE), FCE shows much stronger grain refine ability and much weaker grain orientation concentration. The significant grain refinement and heterostructures depend on the severe shear strain from FCE. The heterostructures of sample subject to FCE transfer from bimodal structure to gradient structure with the decrease of temperature, as the grains in the surface of sample are all refined to ultrafine scale. Both these two heterostructures can realize the improvement of strength and strain hardening effect simultaneously.
双峰晶粒结构导致金属材料具有高强度和应变硬化效应。在本研究中，提出了一种称为流动控制挤压（FCE）的有效方法来实现纯铜的异质结构。与传统挤压（CE）相比，FCE表现出更强的晶粒细化能力和更弱的晶粒取向集中。显著的晶粒细化和异质结构取决于FCE产生的严重剪切应变。随着样品表面的晶粒全部细化到超细尺度，经FCE处理的样品的异质结构随着温度降低从双峰结构转变为梯度结构。这两种异质结构都能同时实现强度和应变硬化效应的提高。
