Strain, stress and stress relaxation in oxidized ZrCuAl-based bulk metallic glass. (November 2020)

• Record Type: Journal Article
• Authors: Haratian, Saber; Niessen, Frank; Grumsen, Flemming B.; Nancarrow, Mitchell J.B.; Pereloma, Elena V.; Villa, Matteo; Christiansen, Thomas L.; Somers, Marcel A.J.
• Is Part Of: Acta materialia. Volume 200(2020)
• Page Start: 674
• Page End: 685
• Publication Date: 2020-11
• Subjects: ZrCuAl-based bulk metallic glass -- Gaseous Oxidizing -- Self-healing mechanism -- Residual stress -- X-ray diffraction sin2ψ method -- FIB-DIC method; Materials -- Periodicals; Materials science -- Periodicals; Materials -- Mechanical properties -- Periodicals; Metallurgy -- Periodicals; Chemistry, Inorganic -- Periodicals; 620.112
• DOI: 10.1016/j.actamat.2020.09.049
• Languages: English
• ISSNs: 1359-6454

Abstract

Abstract: Surface engineering of Zr51.3 Al8.5 Cu31.3 Ni4 Ti4.9 bulk metallic glass (BMG) by gaseous oxidizing below the glass-transition temperature is investigated as a means to introduce compressive residual stress in the surface region. The ZrCuAl-based BMG was exposed to an extremely low oxygen partial pressure of 10 −41 bar at 600 K for 60 h. The oxidizing treatment led to the formation of an internal oxidation zone, consisting of finely dispersed nano-crystalline cubic ZrO2 (c-ZrO2 ), metallic regions inclined with the surface and Cu-hillocks at the surface. The stresses introduced by the volume expansion associated with oxidation were evaluated from i) the lattice strains within c-ZrO2, as determined with an X-ray diffraction (XRD) based method, and ii) strain-relaxation as a response to annular focused ion beam (FIB) milling, as monitored with digital image correlation (DIC). XRD analysis yielded -1.5 GPa (compressive stress) in the nano-crystalline c-ZrO2, while the strain relaxation monitored with FIB-DIC analysis indicated compressive residual stresses of −1.4 GPa in the internal oxidation zone. The strains and stresses determined with the independent measurement methods are discussed. The quantitative macro-strains are discussed in relation to the microstructural features and stress relaxation mechanisms during evolution of the internal oxidation zone. Graphical abstract: Image, graphical abstract