Iranian Journal of Ceramic Science & Engineering
1- Department of Materials Science and Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz,
2- Department of Materials Science and Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, ,zbalak1983@gmail.com
3- Department of Materials Science and Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran
2- Department of Materials Science and Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, ,
3- Department of Materials Science and Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran
Abstract: (880 Views)
Medium entropy high temperature composites based on ZrB2-HfB2-TiB2 with carbon additives silicon carbide, silicon-carbon nanotube and silicon-graphite were consolidated by spark plasma sintering method. Sintering of the samples was done at a temperature of 2000 C with a holding time of 10 minutes and a pressure of 40 MPa. The effect of carbon additives on mechanical properties including hardness and fracture toughness of sintered samples was investigated and analyzed and finally compared with the sample without additives. The images of the effect of hardness indent, the crack growth path and also the fracture surface of the sample were taken with a scanning electron microscope (FESEM). The results show a significant increase in the hardness and fracture toughness in the samples with carbon additives compared to without additives; this increase can be due to the presence of carbon additives and their reactions with surface oxides and reducing the amount of surface oxides, reducing the percentage of porosity, higher relative density (For example 98.5% for sample containing Si and Gr in comparison with 75.5% for without additives), increase the amount of solid solution formation, and decrease the grain size. Also, by examining the path of crack growth, it was observed that the mechanisms of toughening are crack deviation, grain fracture, and crack branching.
Type of Study: Research |
Subject:
Structural Oxide and Non-Oxide Ceramics
Received: 2024/01/27 | Accepted: 2024/04/23
Received: 2024/01/27 | Accepted: 2024/04/23
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