By adjusting the particle size of Ti6Al4V(TC4) powders and the distribution of boron particles, a high-performance heterogeneous network structure titanium matrix composites were fabricated through the spark plasma sintering (SPS) technique. In the present work, TiB whisker (TiBw) are in situ synthesized around the boundaries of the small size TC4 (STC4) particles, and formed into a TiBw network structure. The STC4 particles of the network surround the larger size TC4 (LTC4) particles to form a new heterogeneous network structure similar to the shape of a sunflower. The heterogeneous network structure consisted of coarse grain zones (LTC4) and fine grain zones (TiB/STC4) is formed in the microstructure. In light of tensile results, the tensile strength and ductility of TiB/TC4 composites with heterogeneous network structure are about 987.5 MPa and 11.5%, respectively, which are 16.6% and 35.3% higher than those of TC4 alloy. The improvement of mechanical properties is mainly due to the interface strengthening mechanism of heterogeneous network structure and the hindrance and pinning mechanism of reinforcements to dislocation movement. The improvement of ductility depends on the inhibition of crack propagation by the heterogeneous network structure and the existence of high ductility coarse grain zone.

通过调整Ti6Al4V(TC4)粉末的粒径和硼颗粒的分布，采用放电等离子烧结（SPS）技术制备了高性能异质网络结构钛基复合材料。在目前的工作中，TiB 晶须 (TiBw) 在小尺寸 TC4 (STC4) 颗粒的边界周围原位合成，并形成 TiBw 网络结构。网络的STC4颗粒围绕着较大尺寸的TC4（LTC4）颗粒形成类似于向日葵形状的新型异质网络结构。微观结构中形成了由粗晶区（LTC4）和细晶区（TiB/STC4）组成的异质网络结构。从拉伸结果来看，具有异质网络结构的TiB/TC4复合材料的拉伸强度和延展性分别约为987.5 MPa和11.5%，分别比TC4合金高16.6%和35.3%。力学性能的提高主要是由于异质网络结构的界面强化机制和增强体对位错运动的阻碍和钉扎机制。延展性的提高取决于不均匀网络结构对裂纹扩展的抑制和高延展性粗晶区的存在。