Sun Yi, Zhang Jian, Luo Guoqiang, Shen Qiang, Zhang Lianmeng
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China.
Materials (Basel). 2018 Apr 2;11(4):544. doi: 10.3390/ma11040544.
In this paper, titanium matrix composites with in situ TiB whiskers were synthesized by the plasma activated sintering technique; crystalline boron and amorphous boron were used as reactants for in situ reactions, respectively. The influence of the sintering process and the crystallography type of boron on the microstructure and mechanical properties of composites were studied and compared. The densities were evaluated using Archimedes' principle. The microstructure and mechanical properties were characterized by SEM, XRD, EBSD, TEM, a universal testing machine, and a Vickers hardness tester. The prepared composite material showed a high density and excellent comprehensive performance under the PAS condition of 20 MPa at 1000 °C for 3 min. Amorphous boron had a higher reaction efficiency than crystalline boron, and it completely reacted with the titanium matrix to generate TiB whiskers, while there was still a certain amount of residual crystalline boron combining well with the titanium matrix at 1100 °C. The composite samples with a relative density of 98.33%, Vickers hardness of 389.75 HV, compression yield strength of up to 1190 MPa, and an ultimate compressive strength of up to 1710 MPa were obtained. Compared with the matrix material, the compressive strength of TC4 titanium alloy containing crystalline boron and amorphous boron was increased by 7.64% and 15.50%, respectively.
本文采用等离子体活化烧结技术合成了原位生成TiB晶须的钛基复合材料；分别以晶体硼和非晶硼作为原位反应的反应物。研究并比较了烧结工艺和硼的晶体学类型对复合材料微观结构和力学性能的影响。采用阿基米德原理评估密度。通过扫描电子显微镜（SEM）、X射线衍射仪（XRD）、电子背散射衍射仪（EBSD）、透射电子显微镜（TEM）、万能试验机和维氏硬度计对微观结构和力学性能进行表征。在1000℃、20MPa、保温3min的等离子体活化烧结条件下，制备的复合材料具有高密度和优异的综合性能。非晶硼比晶体硼具有更高的反应效率，它与钛基体完全反应生成TiB晶须，而在1100℃时仍有一定量的残余晶体硼与钛基体结合良好。获得了相对密度为98.33%、维氏硬度为389.75HV、压缩屈服强度高达1190MPa、极限抗压强度高达1710MPa的复合材料样品。与基体材料相比，含晶体硼和非晶硼的TC4钛合金的抗压强度分别提高了7.64%和15.50%。
