Fabrication of (TiB/Ti)-TiAl composites with a controlled laminated architecture and enhanced mechanical properties
Fabrication of (TiB/Ti)-TiAl composites with a controlled laminated architecture and enhanced mechanical properties
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具有受控层状结构和增强机械性能的 (TiB/Ti)-TiAl 复合材料的制造
DOI：
10.1016/j.jmst.2020.06.011
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发表时间：
2021-01-30
影响因子：
10.9
通讯作者：
Geng，Lin
中科院分区：
文献类型：
--
作者：
Ding，Hao;Cui，Xiping;Geng，Lin
采用放电等离子烧结技术，将TiB 2/Ti粉末层和TiAl粉末层交替叠层，成功制备出由TiB/Ti复合层、α2-Ti 3Al界面反应层和γ-TiAl层交替叠层结构的（TiB/Ti）-TiAl复合材料。系统研究了TiB 2/Ti粉层与TiAl粉层厚度比对（TiB/Ti）-TiAl层状复合材料组织演变和力学性能的影响。结果表明，TiB 2颗粒的引入明显抑制了Ti与TiAl反应生成的α2-Ti 3Al层的增厚。随着TiB 2/Ti粉层与TiAl粉层厚度比的增加，最终（TiB/Ti）-TiAl层状复合材料的室温弯曲断裂强度和断裂韧性显著提高，特别是对于由800 μm厚的TiB 2/Ti粉层和400 μm厚的TiAl粉层制备的（TiB/Ti）-TiAl层状复合材料，其断裂韧性和抗弯强度分别达到51.2MPa·m1/2和1456 MPa，比本研究中的整体TiAl合金提高了293%和108%。这是由于添加了高性能的TiB/Ti网络复合层。此外，由400 μm厚TiB 2/Ti粉末层和400 μm厚TiAl粉末层制备的（TiB/Ti）-TiAl复合材料在700 °C下的抗拉强度与网状TiB/Ti复合材料在550 °C下的抗拉强度相当。这意味着（TiB/Ti）-TiAl叠层复合材料的使用温度可能提高150 °C，同时保持了室温下高强度和高韧性的良好结合。最后提出了（TiB/Ti）-TiAl层状复合材料的断裂机理。
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 TiB2particles 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·m1/2and 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.