|
| Preparation Method and Microstructure of In-situ Ni Particle Reinforced ZrB2 Based Ceramics |
| Received:June 21, 2017 Revised:September 15, 2017 |
| View Full Text View/Add Comment Download reader |
| DOI：10.7643/ issn.1672-9242.2017.09.007 |
| KeyWord:ZrB2-based ceramics fracture toughness Ni particle reinforced microstructure mechanical properties |
| Author | Institution |
| LI Bin |
Aviation Office of the Military Representative Office of the Navy Stationed in Guiyang, Guiyang , China |
| HAN Sen-lin |
Aerospace Industry Guiyang AnDa Aerospace Materials Engineering Co., Ltd, Guiyang , China |
|
| Hits: |
| Download times: |
| Abstract: |
| Objective To improve the toughness of ZrB2 based thermal protective ceramics to meet their high thermal shock resistance requirements. Methods The in-situ Ni particles were produced as reinforced phase through precipitation-codeposition on nano ZrB2 powder. Ni-ZrB2 nano composites with uniform distribution were obtained by spark plasma sintering. Effects of Ni content on mechanical properties of Ni-ZrB2 nano composite materials were evaluated through three-point bending test, fracture toughness test and hardness test. And the microstructures of the material were characterized by SEM and XRD. Results Introduction of Ni particles, could effectively improve the relative density of ZrB2, and increase its toughness, strength and hardness. By comparing the different content of Ni, it was suggested that ZrB2-15%Ni had excellent mechanical properties. Its fracture toughness reached to 7.8±0.3 MPa•m1/2, increased by 1 times compared with the original ZrB2 material. From the microstructure obtained through SEM, it can be seen that the Ni particles are uniformly distributed on the surface of ZrB2, and the fracture was characterized by transgranular fracture and intergranular fracture, which was different from the transgranular fracture of the original ZrB2 material. This was also the main reason for the remarkable increase of fracture toughness. Conclusion Introduction of in-situ Ni particles, can effectively improve the ZrB2 material relative density, strength, hardness and fracture toughness. Compared with mechanical properties between different Ni contents, the ZrB2-15%Ni components have the best mechanical properties. This method can effectively improve the fracture toughness of ZrB2 materials and further meet the demand of the high thermal shock resistance. |
| Close |
|
|
|