Journal Article

PUBDB-2021-00008

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Fracture and fatigue behaviour of a laser additive manufactured Zr-based bulk metallic glass

Best, J. (First author)Extern*RWTH*MPG* ; Ostergaard, H. E. ; Li, B. ; Stolpe, M.Extern* ; Yang, F.Extern* ; Nomoto, K. ; Hasib, M. T. ; Muránsky, O.Extern*XFEL.EU* ; Busch, R.Extern* ; Li, X.Extern* ; Kruzic, J. J. (Corresponding author)Extern*

2020
Elsevier Amsterdam [u.a.]

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Please use a persistent id in citations: doi:10.1016/j.addma.2020.101416  doi:10.3204/PUBDB-2021-00008

Abstract: Laser additive manufacturing of bulk metallic glass (BMG) provides an effective bypassing of the critical casting thickness constraints that limit the size of components that can be produced; however, open questions remain regarding the resulting mechanical properties. In this work, a Zr-based BMG known as AMZ4 with composition Zr$_{59.3}$Cu$_{28.8}$Nb$_{1.5}$Al$_{10.4}$ was printed using a laser powder bed fusion (LPBF) technique. Micro X-ray computed tomography results together with electron microscopy imaging revealed porous processing defects in LPBF produced AMZ4 that led to a loss in tensile strength. Fatigue crack growth studies revealed a fatigue threshold, $ΔK_{th}$., of ∼1.33 MPa√m and a Paris law exponent of m = 1.14, which are relatively low values for metallic materials. A K$_{IC}$ fracture toughness of 24−29 MPa√m was found for the LPBF BMG samples, which is much lower than the K$_Q$ of 97−138 MPa√m and K$_{JIC}$ of 158−253 MPa√m measured for the cast alloy with the same composition. The lower fracture toughness of the laser processed AMZ4 was attributed to ∼7.5× higher dissolved oxygen in the structure when compared to the cast AMZ4. Despite the higher level of oxygen, the formation of oxide nanocrystals was not observed by transmission electron microscopy. Oxygen induced toughness loss was confirmed by dissolving elevated concentrations of oxygen into cast AMZ4 rods, which led to a reduction in bending ductility and changes in the short-range order of the glass structure, as revealed by synchrotron X-ray diffraction.

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Contributing Institute(s):

1. PETRA III (PETRA III)

Research Program(s):

1. 6G3 - PETRA III (POF3-622) (POF3-622)
2. FS-Proposal: I-20190031 (I-20190031) (I-20190031)

Experiment(s):

1. PETRA Beamline P07 (PETRA III)

Appears in the scientific report 2020

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Database coverage:
; ; Clarivate Analytics Master Journal List ; Current Contents - Engineering, Computing and Technology ; Essential Science Indicators ; IF >= 5 ; JCR ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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