J. Mater. Sci. Technol. ›› 2013, Vol. 29 ›› Issue (8): 685-701.DOI: j.jmst.2013.05.020

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In-situ Dendrite/Metallic Glass Matrix Composites: A Review

Junwei Qiao   

  1. Laboratory of Applied Physics and Mechanics of Advanced Materials, College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China
  • Received:2013-04-14 Revised:2013-04-28 Online:2013-08-30 Published:2013-07-17
  • Contact: Junwei Qiao
  • Supported by:

    National Natural Science Foundation of China (No. 51101110), the Youth Science Foundation of Shanxi Province, China (No. 2012021018-1), the Research Project Supported by Shanxi Scholarship Council of China (No. 2012-032)

Abstract:

The advanced fabrication of in-situ dendrite/metallic glass matrix (MGM) composites is reviewed. Herein, the semi-solid processing and Bridgman solidification are two methods, which can make the dendrites homogeneously dispersed within the metallic glass matrix. Upon quasi-static compressive loading at room temperature, almost all the in-situ composites exhibit improved plasticity, due to the effective block to the fast propagation of shear bands. Upon quasi-static tensile loading at room temperature, although the composites possess tensile ductility, the inhomogeneous deformation and associated softening dominates. High volume-fractioned dendrites and network structures make in-situ composites distinguishingly plastic upon dynamic compression. In-situ composite exhibits high tensile strength and softening (necking) in the supercooled liquid region, since the presence of high volume-fractioned dendrites lowers the rheology of the viscous glass matrix at high temperatures. At cryogenic temperatures, a distinguishingly-increased maximum strength is available; however, a ductile-to-brittle transition seems to be present by lowering the temperature. Besides, improved tension–tension fatigue limit of 473 MPa and four-point-bending fatigue limit of 567 MPa are gained for Zr58.5Ti14.3Nb5.2Cu6.1Ni4.9Be11.0 MGM composites. High volume-fraction dendrites within the glass matrix induce increased effectiveness on the blunting and propagating resistance of the fatigue-crack tip. The fracture toughness of in-situ composites is comparable to those of the toughest steels and crystalline Ti alloys. During steady-state crack-growth, the confinement of damage by in-situ dendrites results in enhancement of the toughness.

Key words: Bulk metallic glasses, Composites, Mechanical properties, Dynamic loading, Microstructures, Shear bands