title: Significantly enhanced creep resistance of low volume fraction in-situ TiBw/Ti6Al4V composites by architectured network reinforcements.
abstract: We present a new class of TiBw/Ti6Al4V composites with a network reinforcement architecture that exhibits a significant creep resistance compared to monolithic Ti6Al4V alloys. Creep tests performed at temperatures between 773 K and 923 K and stress range of 100 MPa-300 MPa indicate both a significant improvement of the composites creep resistance due to the network architecture made by the TiB whiskers (TiBw), and a decrease of the steady-state creep rates by augmenting the local volume fractions of TiBw in the network region. The deformation behavior is driven by a diffusion-controlled dislocation climb process. Moreover, the activation energies of these composites are significantly higher than that of Ti6Al4V alloys, indicating a higher creep resistance. The increase of the activation energy can be attributed to the TiBw architecture that severely impedes the movements of dislocation and grain boundary sliding and provides a tailoring of the stress transfer. These micromechanical mechanisms lead to a remarkable improvement of the creep resistance of these networked TiBw/Ti6Al4V composites featuring the special networked architecture.
authors.affiliation: School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China.
authors.forename: S
authors.initials: S
authors.lastname: Wang
authors.affiliation: School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China.
authors.forename: L J
authors.initials: LJ
authors.lastname: Huang
authors.affiliation: School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China.
authors.forename: L
authors.initials: L
authors.lastname: Geng
authors.affiliation: Advanced Composites Centre for Innovation and Science (ACCIS), Bristol University, Bristol, BS8 1TR, United Kingdom.
authors.forename: F
authors.initials: F
authors.lastname: Scarpa
authors.affiliation: School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Jiao
authors.affiliation: Institute for Composites Science Innovation (InCSI), School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, PR China.
authors.forename: H X
authors.initials: HX
authors.lastname: Peng