Influence of beryllium addition on the microstructural evolution and mechanical properties of Zr alloys
Influence of beryllium addition on the microstructural evolution and mechanical properties of Zr alloys
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DOI：
10.1016/j.matdes.2014.10.014
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发表时间：
2015
影响因子：
8.4
通讯作者：
Z. Feng;X. J. Jiang;Y. Zhou;C. Xia;S. Liang;R. Jing;X. Zhang;M. Ma;R. P. Liu
中科院分区：
文献类型：
--
作者：
Z. Feng;X. J. Jiang;Y. Zhou;C. Xia;S. Liang;R. Jing;X. Zhang;M. Ma;R. P. Liu
研究了不同Be含量（χ= 0、0.25、0.50、0.75、1.00 wt.%）的Zr -χBe二元合金的组织演变和力学性能。x射线衍射结果表明，添加Be后合金的相组成经历了从α相到α相+ Be2Zr的一系列变化。Be2Zr含量随Be的增加而增加。显微分析表明，前期-β晶粒的形状由不规则的平面结晶逐渐转变为细胞晶，再转变为不规则的枝晶。此外，添加Be对晶粒细化有明显的影响。纯Zr中-β晶粒的平均先验尺寸超过1000 μm。添加0.25 wt.% Be后，-β晶粒的平均尺寸显著减小至170 μm。随着铍含量进一步逐渐增加到1.00 wt.%, Zr -χBe （χ= 0.50, 0.75, 1.00 wt.%）中-β晶粒的平均尺寸逐渐减小至26 μm。影响显著细化的关键因素是Be的加入提高了Zr合金的形核速率和生长限制因子值。含Be的Zr-Be合金的显微组织变化对其力学性能影响很大。在本文中，纯Zr的抗拉强度仅为560mpa左右，延展性保持在14%以上。在zr基合金中，添加Be元素有利于提高合金的拉伸性能。Zr -χBe （χ= 1.00 wt.%）具有最高的抗拉强度（σb= 848 MPa），伸长率为8.6%。扫描电镜结果表明，逐渐加入Be后，Zr合金的断裂方式由韧性断裂转变为脆性断裂。
The microstructural evolution and mechanical properties of Zr–χBe binary alloys with different contents of Be (χ= 0, 0.25, 0.50, 0.75 and 1.00 wt.%) were studied in this paper. X-ray diffraction results showed that the phase composition of alloys underwent a series of changes from α phase to α phase + Be2Zr after Be addition. Moreover, the content of Be2Zr increased with increased Be. Microscopic analysis showed that the shape of prior-β grains gradually transformed from inerratic planar crystallization to cellular crystal and then irregular arborization. In addition, it would have an obvious effect on grain refinement with Be added. The average prior-β grain size in the pure Zr exceeded 1000 μm. The addition of 0.25 wt.% Be dramatically decreased the average size of prior-β grain to 170 μm. With the beryllium further increased gradually to 1.00 wt.%, the average size of prior-β grain in Zr–χBe (χ= 0.50, 0.75, 1.00 wt.%) decreased gradually to 26 μm. The key factor affecting significant refinement is the enhancement in nucleation rate and the growth restriction factor values of Zr alloys resulting from Be addition. The microstructural variation of Zr–Be alloys with Be greatly affected mechanical properties. In this paper, the tensile strength of pure Zr was only approximately 560 MPa, and the ductility remained above 14%. In the Zr-based alloys, adding Be element is beneficial to the improvement of the tensile properties. Zr–χBe (χ= 1.00 wt.%) possessed the highest tensile strength (σb= 848 MPa) and retained an elongation of 8.6%. Scanning electro microscope results indicated that the fracture modes of Zr alloys with gradually added Be changed from ductile fracture to brittle fracture.