The Effect of Grain Size and Dislocation Density on the Tensile Properties of Ni-SiCNP Composites During Annealing
The Effect of Grain Size and Dislocation Density on the Tensile Properties of Ni-SiCNP Composites During Annealing
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DOI：
10.1007/s11665-016-1938-2
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发表时间：
2016-02
影响因子：
2.3
通讯作者：
Chao Yang;Hefei Huang;G. Thorogood;Li Jiang;X. Ye;Zhijun Li;Xingtai Zhou
中科院分区：
文献类型：
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作者：
Chao Yang;Hefei Huang;G. Thorogood;Li Jiang;X. Ye;Zhijun Li;Xingtai Zhou
研究了金属镍-碳化硅纳米颗粒（Ni-3 wt.%）的细化晶粒、提高力学性能和静态再结晶行为SiCNP）复合材料，研磨的时间范围从8至48小时已被检查。一组Ni-SiCNP复合材料样品在300 °C下退火250小时，而另一组样品保持在室温下用于对照目的（参考）。电子背散射衍射结果表明，退火态Ni-SiCNP复合材料在静态再结晶过程中发生了晶粒重组，晶粒尺寸得到了细化。X射线衍射结果表明，低温退火有效地降低了位错密度，这可以用位错堆积模型来解释。此外，拉伸试验表明，退火后的Ni-SiCNP复合材料的强度有显着增加，由于Hall-Petch强化效应的增加，在总伸长率略有增加。在晶粒内部的位错堆积的减少和晶界滑动的增加被认为是在发挥作用的主要机制。研究了显微组织演变与拉伸性能变化之间的关系。
The grain size refinement, enhancement of mechanical properties, and static recrystallization behavior of metallic nickel-silicon carbide nano-particle (Ni-3wt.%SiCNP) composites, milled for times ranging from 8 to 48 h have been examined. One set of Ni-SiCNPcomposite samples were annealed at 300 °C for 250 h, while the other set of samples were maintained at room temperature for control purposes (reference). The electron backscatter diffraction results indicate that the grain size of the annealed Ni-SiCNPcomposite was refined due to grain restructuring during static recrystallization. The x-ray diffraction results indicate that low-temperature annealing effectively reduced the density of dislocations; this can be explained by the dislocation pile-up model. Additionally, the tensile tests indicated that the annealed Ni-SiCNPcomposite had a significant increase in strength due to an increase of the Hall–Petch strengthening effect with a slight increase in the total elongation. The decrease of dislocation pile-up in the grain interiors and the increase in grain boundary sliding are assumed to be the main mechanisms at play. The relationship between the microstructural evolution and the variation of tensile properties is examined in this study.