摘要高熵合金是一种含有多种主元素的新型金属材料。具备特殊的物理、力学性质和广阔的应用前景。但高熵合金相对复杂的体系和结构对其塑性变形的研究造成了一定的障碍。Al-Co-Cr-Cu-Fe-Ni 系高熵合金是研究比较多的高熵合金体系之一,其中,Al0.3Cu0.5CoCrFeNi 高熵合金在合适的热处理条件下具备单一 FCC 结构,具有良好的塑性和强度。因此,它是用来研究高熵合金的塑性变形机理的理想模型材料。 21757
在本毕业设计中,作者用定量 X 射线衍射峰形分析和透射电子显微镜等表征手段对淬火态的 Al0.3Cu0.5CoCrFeNi 高熵合金在经历塑性变形后其内部的晶体结构,缺陷种类及其组态,亚晶尺寸和位错密度进行分析。结果表明,在室温轧制后, Al0.3Cu0.5CoCrFeNi 高熵合金内部的缺陷以全位错为主,但也存在少量的全位错分解以及层错。X 射线衍射线形分析表明,随着轧下量的增加,亚晶尺寸减小,位错密度增大。
关键词 高熵合金 塑性变形 XRD 线形分析 单线法 缺陷
Title Plastic deformation mechanism research of a kind of high-entropy alloy
Abstract
High-entropy alloy (HEA) is a new class of metallic materials with multiple
principal elements. It processes special physical and mechanical
properties, as well as wide application prospect. But the wide range of
available composition and relatively complex microstructure hinders
research on deformation mechanisms of HEAs. Al-Co-Cr-Cu-Fe-Ni system HEA
is one of the best studied HEAs. Among them, Al0.3Cu0.5CoCrFeNi HEA consists
of simple FCC structure under specific heat-treatment condition. It
exhibits good plasticity and moderate strength. Thus, it’s an ideal model
material for plastic deformation mechanism research.
In this graduation dissertation, by taking advantage of X-ray diffraction
(XRD), transmission electron microscopy and other characterization
methods, the author investigated the crystal structure, types of defects
and their configuration, the crystallite size and the dislocation density
of the water-quenched Al0.3Cu0.5CoCrFeNi HEA after plastic deformation. The
results indicated that after cold rolled at room temperature, the defects
in the Al0.3Cu0.5CoCrFeNi HEA were mainly full dislocations, but there were
also certain extent of full dislocation dissociation and stacking
faults.XRD line profile analysis showed quantitatively that the
crystalline size decreased and the dislocation density increased with the
increase of reduction.
Keywords high-entropy alloy plastic deformation XRD line profile
analysis single-line method defects
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