In-situ development of ZrB2 particles and their effect on microstructure and mechanical properties of AA5052 metal-matrix composites
In-situ development of ZrB2 particles and their effect on microstructure and mechanical properties of AA5052 metal-matrix composites
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DOI：
10.1016/j.matdes.2015.05.020
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发表时间：
2015-09-05
影响因子：
8.4
通讯作者：
Mohan, Sunil
中科院分区：
文献类型：
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作者：
Kumar, Narendra;Gautam, Rakesh Kumar;Mohan, Sunil
通过熔融AA5052合金与两种无机盐K2ZrF6和KBF4在860℃的温度下进行原位反应，制备了不同体积百分比（即0、3、6、9和10vol.%）ZrB2颗粒的AA5052/ZrB2复合材料。 形态学。使用标准方法评估它们的机械性能，如硬度和拉伸性能。形貌研究表明，由于 ZrB2 颗粒的存在，富铝相的晶粒尺寸减小。显微组织研究还揭示了ZrB2颗粒的第二相颗粒分布均匀、界面清晰、结合良好、位错和形貌。研究发现ZrB2颗粒大多为纳米尺寸，呈六边形或矩形，但也观察到少量微米尺寸的颗粒。复合材料的密度和硬度随着增强体用量的增加而增加。随着 ZrB2 颗粒体积分数增加至 9 vol.%，极限拉伸强度和 0.2% 屈服强度 (YS) 也不断提高，但超过此成分强度会降低。值得注意的是，随着 ZrB2 颗粒在基体合金中的分散，我们观察到延展性得到改善，这与许多其他复合材料相反。 (C) 2015 Elsevier Ltd. 保留所有权利。
AA5052/ZrB2 composites with different volume percent (i.e. 0, 3, 6, 9 and 10 vol.%) ZrB2 particles were developed by in-situ reaction of molten AA5052 alloy with two inorganic salts K2ZrF6 and KBF4 at a temperature of 860 degrees C. The in-situ composites were characterized by DTA, XRD, SEM, TEM for reaction analysis and morphology. Their mechanical properties like hardness and tensile properties were evaluated using standard methods. Morphology studies show that grain size of Al-rich phase reduces due to the presence of ZrB2 particles. Microstructural studies also reveal the uniform distribution of second phase particles, clear interface, good bonding, dislocations and morphology of ZrB2 particles. It is found that ZrB2 particles are mostly in nano size with hexagonal or rectangular shape, however, few particles in micron size are also observed. Density and hardness of the composites increases with increase in the amount of reinforcement. Ultimate tensile strength and 0.2% yield strength (YS) also improved continuously with increase in the volume fraction of ZrB2 particles up to 9 vol.% but beyond this composition strength reduced. It is important to note that with dispersion of ZrB2 particles in base alloy an improvement in ductility is observed which is contrary to many other composites. (C) 2015 Elsevier Ltd. All rights reserved.