Abstract:

Ground-engaging components in mining machinery are subjected to severe abrasive forces,
leading to performance losses, increased maintenance costs, and unplanned downtime.
Composite overlays incorporating tungsten carbide (WC) particles within Ni-Fe matrices are
widely used to improve wear resistance; however, further improvement of material efficiency
remains a top industrial challenge. Although deep cryogenic treatment (DCT) has been explored
for steels and tool alloys, its application to WC–NiFe composite overlays and the associated
microstructural mechanisms remain largely unexplored. This study investigated the effects of
DCT on the microstructure and wear performance of a WC-reinforced Ni-Fe composite overlay
deposited on a martensitic steel substrate used in mining operations. A combination of G65
abrasive wear testing, scanning electron microscopy (SEM), and in-situ X-ray diffraction (XRD)
was used to examine changes in performance, microstructure, and residual stress state post-
treatment. Applying a DCT to the material noted a reduction in material loss during G65 testing
compared to the as-received condition, indicating a change in the tribological response of the
system. SEM imaging revealed reduced crack thickness between WC particles after DCT,
implying microstructural constraint or partial crack closure. Residual stress analysis supported
this trend, with XRD measurements indicating the development of compressive stresses during
treatment. To further understand and explore the underlying mechanisms, a thermo-mechanical
finite element model was developed in ABAQUS using temperature-dependent material
properties obtained from Thermo-Calc. The simulations provided insight into the magnitude and
spatial distribution of residual stress fields generated during DCT, while experimental XRD data
validate stress evolution predicted by the simulation. Although DCT appeared to modify crack
morphology through compressive stress development, the associated changes in wear behaviour
indicated complex interactions between microstructure, stress state, and abrasive performance.
These findings highlight the direct relationship between the underlying mechanisms correlated to
DCT and wear behaviour. The combined modelling and experimental approach established a
framework for understanding stress evolution in multi-phase composites subjected to DCT,
enabling rational design of overlay systems for extended service life in high-stress, abrasive
environments such as mining operations.

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Mr. Sahejkarn Sidhu