Effect of Milling Time on the Microstructure and Tensile Properties of Ultrafine Grained Ni–SiC Composites at Room Temperature

作     者：Hefei Huang Chao Yang Massey de los Reyes Yongfeng Zhou Long Yan Xingtai Zhou 

作者机构：Shanghai Institute of Applied Physics Chinese Academy of Sciences Institute of Materials Engineering Australian Nuclear Science and Technology Organisation 

出 版 物：《Journal of Materials Science & Technology》 (材料科学技术（英文版）)

年 卷 期：2015年第31卷第9期

页      面：923-929页

核心收录：

学科分类：081702[工学-化学工艺] 0817[工学-化学工程与技术] 0806[工学-冶金工程] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0703[理学-化学] 0802[工学-机械工程] 0801[工学-力学（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：supported by the Knowledge Innovation program of Chinese Academy of Sciences the National Basic Research Program of China (Grant Nos. 2010CB832903 and 2010CB834503) the China-Australia Joint Research Project (Grant No. 2014DFG60230) 

主　　题：Ni SiCNp compositeMechanical alloyingSpark plasma sinteringTransmission electron microscopyTensile testUltra fine grained (UFG) 

摘      要：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-Perch strength- ening 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 irrevers- ible inelastic deformation.