The co-deposition of (F)GO into CMMCs has a significant effect on their mechanical properties (Figures and). FGO-CMMC (0.25CD) shows the most pronounced effects, as its hardness (1.67 GPa) is considerably lower than for both Cu Ref(0.25CD) and GO-CMMC (0.25CD) (2.97 and 2.39 GPa). This accounts for ~43 and 18% reduction in hardness for the copper coating upon FGO and GO incorporation when deposited at 0.25 A/dm 2 . This results in a coating that has lower elasticity and higher ductility -desired properties in solid lubrication systems facilitated by soft metals. Less significant reductions in H values were reported when deposited at 0.5 A/dm 2 , with values of 2.72, 3.03 and 3.24 GPa for FGO-CMMC (0.5CD), GO-CMMC (0.5CD) and Cu Ref(0.5CD) coatings, confirming a 16 and 7% reduction in hardness of the copper coatings by FGO and GO incorporation. These findings are in contrast to literature, which shows that bulk graphene-copper matrix composites can achieve increases in Vickers Hardnesses of up to 300% compared to pure copper. However these bulk systems are produced in methods where graphene contributes to the grain refinement of the copper composite; the incorporation of graphene during the sintering prevents Cu-grain growth and, therefore, promote increased resistance to mechanical deformation. The low temperature and slow growth rate in the electrodeposition conditions applied for FGO-CMMC and GO-CMMC production are not limited by such effects, providing a route to lowering the hardnesses of the composites, rather than increasing them. The elastic moduli of all FGO-CMMC and GO-CMMC are (within error) consistent with observed values for their Cu Ref counterparts, albeit with a higher degree of deviation as a cause of the rougher surfaces from graphene incorporation.