Mechanical phase mapping of the Taza meteorite using correlated high‐speed nanoindentation and EDX

Abstract

Meteorites have one of the most unique and beautiful microstructures, the Widmanstätten structure. This consists of large, elongated bands which form an intricate octahedral lace of crystalline metal. This structure makes meteorites an ideal case to demonstrate the capabilities of mechanical phase mapping using high-speed nanoindentation. In this work, the mechanical properties and composition of the Taza meteorite were mapped using ∼100,000 indentations to statistically determine the properties of the individual phases. Five microstructural phases were characterized in this meteorite: Kamacite, Plessite, Tetrataenite, Cloudy Zone, and Schreibersite. Mechanical phase identification was confirmed using EDX measurements, and the first direct, pointto-point correlation of EDX and large-scale indentation maps was achieved. Mechanical phase maps showed superior phase contrast to EDX in two phases. An indentation property map or a mechanical phase map using a 2D histogram was used to visualize and statistically characterize the phases and identify trends in their relationships.

Laser Melting of Mechanically Alloyed FeNi: A Study of the Correlation between Microstructure and Texture with Magnetic and Physical Properties

“…The nanohardness value for samples S5 and R5 is 4.58 and 4.55 GPa, respectively. These hardness values are comparable with that of the tetrataenite phase of the Taza meteorite …”

Viscoplastic Rheology of α‐Quartz Investigated by Nanoindentation

“…Nanoindentation is a common method in the materials sciences and can enable ductile deformation even at low homologous temperatures (T/T m < 0.3) (C. Fischer‐Cripps, 2011; Hardiman et al., 2016; Oliver & Pharr, 2004). Recently, several studies have successfully used instrumented nanoindentation for the study of geologic materials (Ceccato et al., 2021 (in review); Goldsby et al., 2004; Kranjc et al., 2016; Kumamoto et al., 2017; Sly et al., 2020; C. Thom et al., 2019; C. A. hom et al., 2018; Wheeler, 2021). The primary advantage of nanoindentation is that it provides self‐confined deformation because the geometry of the indenter tip inhibits cracking even at low temperatures (Oliver & Pharr, 1992).…”

“…Thom et al, 2019;C. A. hom et al, 2018;Wheeler, 2021). The primary advantage of nanoindentation is that it provides self-confined deformation because the geometry of the indenter tip inhibits cracking even at low temperatures (Oliver & Pharr, 1992).…”

Multi‐Material Strain Mapping with Scanning Reflectance Anisotropy Microscopy

“…However, for plane stress, the combined use of SRAM (∝ϵ xx − ϵ yy ) and Raman (∝ϵ xx + ϵ yy ) would allow to decouple ϵ xx and ϵ yy without the assistance of FEM simulations. SRAM could also be used in conjunction with destructive mechanical techniques like nanoindentation, [45] allowing for mapping of both the strain distribution as well as the mechanical properties of the sample (hardness and Young's modulus).…”