Improving the plasticity and strength of Fe-Nb-B ultrafine eutectic composite
Improving the plasticity and strength of Fe-Nb-B ultrafine eutectic composite
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DOI：
10.1016/j.matdes.2015.03.053
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发表时间：
2015-07-05
影响因子：
8.4
通讯作者：
Kim, Ki Buem
中科院分区：
文献类型：
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作者：
Kim, Jeong Tae;Hong, Sung Hwan;Kim, Ki Buem
本研究通过控制硼（B）的含量，实现了Fe-Nb二元共晶合金的组织演变和力学性能的提高。添加B导致具有不同长度尺度不均匀性的独特微结构的演变，即，形成双峰结构、含有长度尺度不均匀性的球形团簇和初生NbFeB相的沉淀。随着显微组织的演变，包括屈服强度和塑性应变的力学性能显著提高，分别从1100 MPa提高到1660 MPa和从接近4%提高到接近20%。通过扫描电子显微镜（SEM）和原子力显微镜（AFM）分析了试样的变形机理、断口形貌和侧表面形貌。从这些观察结果可以看出两种不同的塑性变形机制：（1）形变诱导的枝晶/共晶团的旋转运动和（2）形变诱导的片层组织的界面迁移。(C)2015爱思唯尔有限公司版权所有。
In the present study, the microstructural evolution and improving the mechanical properties have been achieved in Fe-Nb binary eutectic alloy via controlling the amount of boron (B) content. The addition of B leads to evolution of a unique microstructure with different length-scale heterogeneities, i.e., formation of bimodal structure, spherical colonies containing length-scale heterogeneity and precipitation of primary NbFeB phase. Following the evolution of microstructure, the mechanical properties including yield strength and plastic strain were significantly enhanced from 1100 MPa to 1660 MPa and from similar to 4% to similar to 20%, respectively. To elucidate deformation mechanism fracture topography and lateral surface morphology analyses are performed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). From these observations two distinct plastic deformation mechanisms can be suggested by following ways: (1) deformation-induced rotation motion of dendrites/eutectic colonies and (2) deformation-induced interface migration of lamellar structure. (C) 2015 Elsevier Ltd. All rights reserved.