Page 68 - MSAM-1-2

Materials Science in Additive Manufacturing Cold spray additive manufacturing of Cu-based materials

on pure copper cold spray coatings, cold-sprayed copper analysis. The I /I ratio for composite particles was 0.72,
G
D
GNP (1 vol.%) coatings, and spark plasma sintered copper which became 0.62 after the cold spray process. This result
GNP coatings. Interestingly, the friction coefficient of shows that the damage to graphene was not significant. It is
cold-sprayed copper GNP (1 vol.%) coatings was 20% possible that the low temperature of carrier gas could have
lesser than that of pure copper cold spray coatings. prevented thermal damage and oxidation of graphene.
Furthermore, when compared to spark plasma sintered Furthermore, the band for the graphene also did not shift.
copper-based coatings, the cold-sprayed copper-GNP It was at the same position 1588 cm for both composite
-1
coatings performed better at the same volume percent of powders and coatings, indicating very low compressive
GNP in the copper matrix. The anti-friction performance residual stress induced during the cold spray process. The
was the optimum for copper-GNP cold-sprayed composite interatomic forces between graphene and copper particles
coatings. The worn surface of copper-GNP cold-sprayed due to the high electron density at the interface between
coatings had very little debris and delamination. The GNPs copper and graphene prevented the pullout of graphene
existing at the worn surface were fractured during the wear
test, which provided a graphene-rich film that lubricates
the worn surface. Hence, the anti-friction performance is
significantly improved .
[52]
In another work, Choi et al. deposited graphene-
[53]
copper cold spray coatings with copper powders and
graphene grown on copper powders by CVD technique. As
reported, the copper particles were coated with graphene
through CVD process by introducing the powder copper
particles to CH , H , and Ar gases at 100 Pa pressure for
4
2
30 min. The graphene-coated copper powder particles were
then mixed with pure copper particles at a 1:3 ratio mixture,
which was then cold sprayed onto an aluminum plate. The
author claims to have created graphene copper composite
cold spray coatings with minimal damage to graphene. The Figure 15. The measured coefficient of friction for copper and composite
possibility of agglomeration due to high surface energy and film . (Reprinted from Diamond and Related Materials, 116, Choi,
[53]
Van der Waals forces of graphene could also be avoided by J., Okimura, N., Yamada, T., Hirata, Y., Ohtake, N., and Akasaka, H.,
the CVD processing technique followed by cold spraying. Deposition of graphene-copper composite film by cold spray from
The damage to graphene that happened during cold spray particles with graphene grown on copper particles, 108384, 2021, with
was evaluated by I /I ratio through Raman spectroscopy permission from Elsevier).
D
G
A B

C D

Figure 14. Scanning electron microscopy micrographs of sliding mark
on the copper surface and composite film surface . (Reprinted from Figure 16. Coefficient of friction for copper, copper-MoS , and copper-
[53]
2
Diamond and Related Materials, 116, Choi, J., Okimura, N., Yamada, T., MoS -WC . (Reprinted from Tribology International, 123, Zhang, Y.,
[63]
2
Hirata, Y., Ohtake, N., and Akasaka, H., Deposition of graphene-copper Epshteyn, Y., and Chromik, R. R., Dry sliding wear behavior of cold-
composite film by cold spray from particles with graphene grown on sprayed Cu-MoS2 and Cu-MoS2-WC composite coatings: The influence
copper particles, 108384, 2021, with permission from Elsevier). of WC, 296 – 306, 2018, with permission from Elsevier).
Volume 1 Issue 2 (2022) 12 https://doi.org/10.18063/msam.v1i2.12