Controlling ζ-Ta4C3- laminate growth in TaC0.6 ceramic by addition of Cu and its effect on mechanical properties
| Autor: | Zhaoping Hou, Guihong Geng, Faqiang Shi, Yujin Wang, Limeng Liu |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Materials science
Composite number 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Microstructure Hot pressing 01 natural sciences 0104 chemical sciences chemistry.chemical_compound Fracture toughness chemistry Flexural strength Electrical resistivity and conductivity visual_art visual_art.visual_art_medium General Materials Science Ceramic Composite material 0210 nano-technology Tantalum carbide |
| Zdroj: | Materials Chemistry and Physics. 225:256-260 |
| ISSN: | 0254-0584 |
| DOI: | 10.1016/j.matchemphys.2018.12.093 |
| Popis: | Tantalum carbide ceramics with an overall composition of TaC 0.6 were prepared by hot pressing at 1700 °C for 1 h under 30 MPa pressure with fcc TaC and bcc Ta powder as starting materials. Effects of adding 0–30 mol% Cu on densification, phase formation, microstructural evolution, mechanical properties and electrical conductivity of the obtained composite ceramics were investigated. Full density could be reached at 20 mol% Cu addition and above. Reactions between TaC and Ta resulted in the final phases of hexagonal Ta 2 C and rhombohedral ζ-Ta 4 C 3-x . Plate-shaped ζ laminate grew in both TaC and Ta 2 C and consequently had their sizes confined by the parental grains. Addition of 20–30 mol% Cu could significantly grow the intermediate Ta 2 C grains, hence controlling length of the ζ laminates precipitated in them to form bimodal microstructures consisting of large grains. The 20 mol% Cu composition had a better flexural strength (706 ± 46 MPa) and fracture toughness (9.2 ± 1.7 MPa m 1/2 ). Electrical resistivity at room temperature of the composites decreased with Cu content from 1.03 μΩ m at 0 mol% addition to 0.12 μΩ m at 30 mol% Cu. |
| Databáze: | OpenAIRE |
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