Zou Xiong, Yang Yu, Liu Junliang, Sun Tingting, Zhang Fuqin
Powder Metallurgy Research Institute, Central South University, Changsha 410083, China.
Materials (Basel). 2025 Mar 24;18(7):1429. doi: 10.3390/ma18071429.
In order to achieve a balance between the strength and ductility of titanium matrix composites (TMCs), a spray deposition method was employed to deposit carbon nanotubes (CNTs) onto the surface of Ti foil. Subsequently, spark plasma sintering (SPS) at 850 °C and an additional 1 h heat treatment at 880 °C were utilized to fabricate two laminated composites of different composition, namely, CNTs/Ti (SPS) and in situ TiC/Ti (SPS+HT). The microstructure evolution, mechanical properties, and strengthening and fracture mechanisms of laminated composites were systematically studied. The results revealed that after sintering at 850 °C, the reaction between CNTs and the titanium matrix was limited. However, after a 1 h heat treatment at 880 °C, CNTs were completely transformed into TiC, while the titanium matrix remained α phase without undergoing phase transformation. Through rolling and annealing, TiC particles were refined to 500 nm and exhibited a flattened shape. The in situ TiC/Ti layered composite material exhibited a tensile strength (UTS) of 491.51 MPa, which was a 29.63% improvement compared to pure titanium (379.16 MPa), and significantly higher than the UTS of CNTs/Ti samples (419.65 MPa). The primary strengthening mechanism was load transfer strengthening. The elongation (EL) remained at 26.59%, slightly lower than pure titanium (29.15%) and CNTs/Ti samples (27.51%). This can be attributed to the increased connectivity of the matrix achieved through rolling, which enhanced the ability to passivate cracks and prolonged the crack propagation path. This study presents a method for preparing laminated titanium matrix composites with both strength and ductility by controlling the heat treatment process.
为了在钛基复合材料（TMCs）的强度和延展性之间取得平衡，采用喷雾沉积法将碳纳米管（CNTs）沉积在钛箔表面。随后，利用850℃的放电等离子烧结（SPS）和880℃额外1小时的热处理来制备两种不同成分的层状复合材料，即CNTs/Ti（SPS）和原位TiC/Ti（SPS+HT）。系统地研究了层状复合材料的微观结构演变、力学性能以及强化和断裂机制。结果表明，在850℃烧结后，碳纳米管与钛基体之间的反应有限。然而，在880℃进行1小时热处理后，碳纳米管完全转变为TiC，而钛基体仍为α相，未发生相变。通过轧制和退火，TiC颗粒细化至500nm并呈现扁平形状。原位TiC/Ti层状复合材料的抗拉强度（UTS）为491.51MPa，与纯钛（379.16MPa）相比提高了29.63%，且显著高于CNTs/Ti样品的UTS（419.65MPa）。主要强化机制是载荷传递强化。伸长率（EL）保持在26.59%，略低于纯钛（29.15%）和CNTs/Ti样品（27.51%）。这可归因于通过轧制实现的基体连通性增加，增强了钝化裂纹的能力并延长了裂纹扩展路径。本研究提出了一种通过控制热处理工艺制备兼具强度和延展性的层状钛基复合材料的方法。
