Issue 74

N. S. Dhongade et alii, Fracture and Structural integrity, 74 (2025) 1-19; DOI: 10.3221/IGF-ESIS.74.01

(e) (f) Figure 20: SEM micrographs illustrating the worn surface morphology of AA7075/TiB 2 /ZrO 2 hybrid composite: (e) Composite containing 5 wt.% TiB 2 and 6 wt.% ZrO 2 , revealing wear features at standard magnification. (f) High-magnification image of the same composite, detailing microstructural deformation, particle distribution, and wear mechanisms.

EDS SPECTRUM ANALYSIS OF WORN SURFACES

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igs. 21, 22, and 23 illustrate the Energy Dispersive X-ray Spectroscopy (EDS) elemental mapping of the worn surfaces of AA7075 hybrid composites reinforced with varying concentrations of TiB 2 and ZrO 2 particles. The EDS spectra confirm the elemental composition, revealing the presence of aluminum (Al), zinc (Zn), iron (Fe), oxygen (O), boron (B), zirconium (Zr), and titanium (Ti), as detailed in Tab. 3. Prolonged sliding contact induces severe surface deformation, resulting in delamination and the subsequent development of a protective oxide layer on the worn regions, which plays a crucial role in mitigating further material degradation. There is an increase in the temperature in between the rotating disc and wear specimen due to dislocations of the surface by shear force. The worn surface which has undergone large plastic deformation is further exposed to the environment. The active ions on the metal surface due to high temperature rise leads to oxidation. A protective oxide layer is formed around the material may reduce the rate of corrosion which also acts as a lubricant, reducing the wear rate. The presence of oxygen in the EDS spectrum confirms the development of this oxide layer on the worn surfaces. There is the presence of Fe in the spectrum graph as the result of mechanically mixed layer (MML) formation due to rubbing action between the disc and hybrid composite surface [4, 25].

Figure 21: EDS analysis of the worn surface of AA7075/5%TiB 2 /2%ZrO 2 hybrid composite.

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