Strong work hardening in a high niobium-containing TiNi-based bulk glassy alloy composite

• Published in: Journal of materials research 2021-03, Vol.36 (6), p.1367-1375
• Main Authors: Chen, S. S., Yin, J., Zou, J. H., Qi, K., Song, P. D., Hu, Q.
• Format: Article
• Language: English
• Subjects: Amorphous alloys; Applied and Technical Physics; Biomaterials; Chemistry and Materials Science; Composite materials; Crystal lattices; Edge dislocations; Fracture strength; Inorganic Chemistry; Intermetallic compounds; Materials Engineering; Materials research; Materials Science; Mechanical properties; Nanotechnology; Nickel base alloys; Nickel compounds; Niobium; Plastic deformation; Room temperature; Shape memory alloys; Shear bands; Suction; Titanium compounds; Work hardening; Work softening
• ISSN: 0884-2914; 2044-5326
• DOI: 10.1557/s43578-021-00199-1

In this study, a high niobium-containing bulk glassy alloy composite Ti 41 Ni 39 Nb 17.5 Al 2.5 consisting of amorphous, B2-TiNi and β -Nb phases was fabricated through in situ precipitation strategy by utilizing copper-mold suction casting. Upon compressive loading, the composite alloy showed a pronounced average plastic strain of (17.6 ± 3.5)% and a high fracture strength of (2279 ± 33) MPa together with a strong work-hardening deformation behavior. The volume fraction of the amorphous phase in the composite was determined to be around 23 vol%. The work softening caused by the formation of shear bands can be compensated by the work hardening arising from the pile-ups of dislocation and severe lattice distortion in the precipitated crystals and thereby stabilize the plastic deformation of the composite material. The findings imply that the room-temperature mechanical properties of bulk glassy alloy composites can be well tailored by selecting suitable reinforcers. Graphic abstract