Effect of Milling Time on the Microstructure and Tensile Properties of Ultrafine Grained Ni-SiC Composites at Room Temperature
Effect of Milling Time on the Microstructure and Tensile Properties of Ultrafine Grained Ni-SiC Composites at Room Temperature
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DOI：
10.1016/j.jmst.2014.12.009
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发表时间：
2015-09-01
影响因子：
10.9
通讯作者：
Zhou, Xingtai
中科院分区：
文献类型：
--
作者：
Huang, Hefei;Yang, Chao;Zhou, Xingtai
在行星式球磨机中制备块状金属镍-碳化硅纳米颗粒（Ni-SiCNP）复合材料，球磨时间为8至48小时，并使用放电等离子烧结（SPS）炉进行烧结。 Ni-SiCNP 复合材料的微观结构通过透射电子显微镜 (TEM) 进行表征，并通过拉伸测量研究其机械性能。 TEM 结果显示 SiCNP 颗粒在基体内、孪晶之间或沿晶界 (GB) 分散良好，并且存在堆垛层错和孪晶结构，这是具有低堆垛层错能的材料的特征。还观察到位错线与不可塑性变形的 SiCNP 相互作用。 Hall-Petch 强化和弥散强化机制之间存在协同关系，这对 Ni-SiCNP 复合材料的力学性能有很大影响。在铣削时间为 48 小时的 Ni-SiCNP 复合材料中发现最大屈服强度和拉伸强度，而由于 SiCNP 显着团聚，铣削时间超过 8 小时的材料强度增加率急剧下降。当球磨时间延长时，球磨过程会形成纳米级超细晶粒 (UFG) Ni-SiCNP 复合材料，从而大大增强这些材料的强度。然而，在出现不可逆非弹性变形之前，应综合考虑伸长率的急剧下降。版权所有(C)2015，材料科学与技术学报编辑部。由爱思唯尔有限公司出版。版权所有。
Bulk metallic nickel-silicon carbide nano-particle (Ni-SiCNP) composites, with milling time ranged from 8 to 48 h, were prepared in a planetary ball mill and sintered using a spark plasma sintering (SPS) furnace. The microstructure of the Ni-SiCNP composites was characterized by transmission electron microscopy (TEM) and their mechanical properties were investigated by tensile measurements. The TEM results showed well-dispersed SiCNP particles, either within the matrix, between twins or along grain boundaries (GB), as well as the presence of stacking faults and twin structures, characteristics of materials with low stacking fault energy. Dislocation lines were also observed to interact with the SiCNP which were plastically nondeformable. A synergistic relationship existed between Hall-Petch strengthening and dispersion strengthening mechanisms, which was shown to greatly influence the mechanical properties of the Ni-SiCNP composites. Both the maximum yield and tensile strengths were found in the Ni-SiCNP composite with a milling time of 48 h, whereas the increased rate of strengths drastically decreased in material milled above 8 h due to the significant SiCNP agglomeration. The ball milling process resulted in the formation of nano-scale, ultra-fine grained (UFG) Ni-SiCNP composites when the milling time was extended for longer periods, greatly strengthening these materials. The sharp decrease in elongation percentages, however, should be comprehensively considered before irreversible inelastic deformation. Copyright (C) 2015, The editorial office of Journal of Materials Science & Technology. Published by Elsevier Limited. All rights reserved.