Microstructure,fracture, electrical properties and machinability of SiC-TiNbC composites |
| |
| Affiliation: | 1. Institute of Materials Research, Slovak Academy of Sciences, Watsonova 47, Košice, Slovakia;2. Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dúbravská Cesta 9, Bratislava, Slovakia;1. School of Materials Science and Engineering, Beihang University, Beijing 100191, China;2. Center for Integrated Computational Materials Science, International Research Institute for Multidisciplinary Science, Beihang University, Beijing 100191, China;1. Institute of Inorganic Chemistry, Slovak Academy of Science, Dúbravská cesta 9, 845 36 Bratislava, Slovakia;2. Institute of Materials Research, Slovak Academy of Sciences, Watsonova 47, 043 53 Košice, Slovakia;3. Alexander Dubček University of Trenčín, and RONA, j.s.c, Študentská 2, 911 50 Trenčín, Slovakia;1. State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China;2. Key Laboratory of Inorganic Functional Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China;3. University of Chinese Academy of Sciences, Beijing 100039, China;1. Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dúbravska cesta 9, 845 36, Bratislava, Slovak Republic;2. Institute of Materials Research, Slovak Academy of Sciences, Watsonova 47, 040 01, Košice, Slovak Republic;3. Pavol Jozef Šafárik University in Košice, Faculty of Science, Institute of Physics,Park Angelinum 9, 040 01, Košice, Slovak Republic |
| |
| Abstract: | Three SiC based composites with 30, 40 and 50% of additives (Ti and NbC with ratio of 9:16) have been prepared by hot pressing without other sintering additives. The microstructure, porosity, and chemical composition were studied using SEM/EDS. Local mechanical properties such as hardness and elastic modulus of individual components of the composite were investigated by nanoindentation. Hardness and fracture toughness of the composites were evaluated by means of Vickers macroindentation. Indentation cracks were observed and their propagation was analyzed. It was shown that the present phases were distributed uniformly. The materials with 40 wt% and 50 wt% TiNbC were almost fully dense with porosity lower than 1%. The individual constituents shown similar elasticity modulus (550–590 GPa). Indentation fracture toughness was comparable in all materials, between 2.7–3.0 MPa.m1/2. Cracks in SiC were mostly straight, transgranular. In other places they propagated both trans- and intergarnularly, often followed SiC/TiNbC and TiNbC/TiNbC grain boundaries. The four-point bending strength was 435 MPa for 30% TiNbC and is comparable in all materials within the error of measurement. These results suggest much lower cohesive strength of TiNbC grain boundaries. Electrical conductivity increased with increasing amount of TiNbC and in all materials was more than 1000 S/m. Consequently, all composites were EDM machinable, the surfaces of the cut were intensively oxidized. |
| |
| Keywords: | Silicon carbide Composite Nanoindentation Hardness Modulus of elasticity |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
