Fabrication of (TiB/Ti)-TiAl composites with a controlled laminated architecture and enhanced mechanical properties
Autor: | Yuanyuan Zhang, Lin Geng, Gao Naonao, Yuan Sun, Ding Hao, Xiping Cui, Lujun Huang |
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Rok vydání: | 2021 |
Předmět: |
Toughness
Materials science Fabrication Polymers and Plastics Mechanical Engineering Composite number Metals and Alloys Spark plasma sintering 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Microstructure 01 natural sciences 0104 chemical sciences Fracture toughness Flexural strength Mechanics of Materials Ultimate tensile strength Materials Chemistry Ceramics and Composites Composite material 0210 nano-technology |
Zdroj: | Journal of Materials Science & Technology. 62:221-233 |
ISSN: | 1005-0302 |
Popis: | The (TiB/Ti)-TiAl composites with a laminated structure composing of alternating TiB/Ti composite layers, α2-Ti3Al interfacial reaction layers of and γ-TiAl layers were successfully prepared by spark plasma sintering of alternately stacked TiB2/Ti powder layers and TiAl powder layers. And the influence of thickness ratio of TiB2/Ti powder layers to TiAl powder layers on microstructure evolution and mechanical properties of the resulting (TiB/Ti)-TiAl laminated composites were investigated systemically. The results showed that the thickening of α2-Ti3Al layers which originated from the reaction of Ti and TiAl was significantly hindered by introducing TiB2 particles into starting Ti powders. As the thickness ratio of TiB2/Ti powder layers to TiAl powder layers increased, the bending fracture strength and fracture toughness at room temperature of the final (TiB/Ti)-TiAl laminated composites were remarkably improved, especially for the (TiB/Ti)-TiAl composites prepared by TiB2/Ti powder layers with thickness of 800 μm and TiAl powder layers with thickness of 400 μm, whose fracture toughness and bending strength were up to 51.2 MPa·m1/2 and 1456 MPa, respectively, 293 % and 108 % higher than that of the monolithic TiAl alloys in the present work. This was attributed to the addition of high-performance network TiB/Ti composite layers. Moreover, it was noteworthy that the ultimate tensile strength at 700 °C of (TiB/Ti)-TiAl composites fabricated by 400 μm thick TiB2/Ti powder layers and 400 μm thick TiAl powder layers was as high as that at 550 °C of network TiB/Ti composites. This means the service temperature of (TiB/Ti)-TiAl laminated composites was likely raised by 150 °C, meanwhile a good combination of high strength and high toughness at ambient temperature could be maintained. Finally, the fracture mechanism of (TiB/Ti)-TiAl laminated composites was proposed. |
Databáze: | OpenAIRE |
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