标题: | 以即时中子研究CoCrFeMnNi等莫耳高熵合金疲劳行为 Study on the Fatigue Behavior of equiatomic CoCrFeMnNi High Entropy Alloy by in-situ Neutron Diffraction Investigation |
作者: | 隋宗睿 黄尔文 Sui, Tsung-Ruei Huang, E-Wen 材料科学与工程学系所 |
关键字: | 中子绕射;微结构;高熵合金;金属与合金;疲劳;Neutron Diffraction;Microstructure;High Entropy Alloy;Alloys and Compounds;Fatigue |
公开日期: | 2017 |
摘要: | 钴铬铁锰镍等莫尔高熵合金在常温常压下为单一面心立方材料,也是目前所知拥有最高韧性之材料,本研究藉由即时中子绕射实验研究钴铬铁锰镍五元等莫耳高熵合金在拉伸及循环应力下的塑变形为差异。藉由比较钴铬铁镍及钴铬铁锰镍高熵合金室温之拉伸性质以研究锰的添加对高熵合金的影响,本研究发现锰的添加虽使降伏强度及最大拉伸强度上升,但同时也降低合金的伸长率;另外,铸造态合金所拥有之大晶粒使得钴铬铁镍及钴铬铁锰镍两合金在室温下便观察到双晶对其塑性变形的影响。在低周疲劳实验中,差排、双晶及差排墙间的互动主宰了钴铬铁锰镍等莫尔高熵合金之疲劳行为。 Equiatomic CoCrFeMnNi high entropy alloy(HEA) is single phase FCC material under room temperature and pressure, also known as the material with highest toughness. This research aims to investigate a five-element HEA CoCrFeMnNi plastic deformation behavior under tensile and cyclic stress by using in-situ neutron diffraction. Then compare the tensile properties at room temperature between CoCrFeNi and CoCrFeMnNi in order to study the effect of adding manganese to HEA. The result shows the addition of manganese increases yield strength and ultimate tensile strength, but at the same time decreases the HEA elongation. Besides, the large grains in as-cast alloy allows the observation of the effect of twinning on plastic deformations of both HEA, CoCrFeNi and CoCrFeMnNi at room temperature. In low cycle fatigue experiment, the interaction between dislocation, twinning and dislocation wall dominates the fatigue behavior of CoCrFeMnNi. |
URI: | http://etd.lib.nctu.edu.tw/cdrfb3/record/nctu/#GT070451559 http://hdl.handle.net/11536/141476 |
显示于类别: | Thesis |