Fabrication and mechanical properties of the titanium matrix composites based on Ti6Al4V-ZrB2-(Si) system

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 2021-07, Vol.819, p.141488, Article 141488
• Main Authors: Jiang, Shan, An, Qi, Cui, Xiping, Xiang, Xuelian, Huang, Lujun, Zhang, Rui, Sun, Yuan, Geng, Lin
• Format: Article
• Language: English
• Subjects: Composite materials; Creep rate; Creep strength; High temperature; Mechanical properties; Metal matrix composites; Powder metallurgy; Refractory materials; Room temperature; Silicides; Silicon; Steady state creep; Tensile strength; Titanium base alloys; Zirconium compounds
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2021.141488

In this work, series of Ti matrix composites based on the Ti6Al4V-ZrB2-(Si) system were successfully fabricated through powder metallurgy. The room-temperature tensile strengths were significantly enhanced to 1063 MPa and 1185 MPa with 4.5 wt% and 9 wt% ZrB2 addition, respectively. The high-temperature tensile strength was enhanced to 501 MPa (600 °C) and 327 MPa (700 °C) for Ti64-4.5 wt%ZrB2 composite, and 693 MPa (600 °C) and 422 MPa (700 °C) for Ti64-9 wt%ZrB2 composite. As for the creep resistance, the Ti64-9 wt%ZrB2 composite exhibited the lowest steady-state creep rate of (4.88 × 10-7 s-1) and the longest creep time to rupture (6.28 h). Adding Si to construct the two-scale network structure further enhanced the mechanical properties, especially at high temperature, the strengths were elevated by 26% and 39% for the Ti64-4.5 wt%ZrB2-1wt.%Si composite at 600 °C and 700 °C, respectively, and the creep resistance was markedly enhanced with the help of the second-scale silicide reinforcement network.