Comparative study of the fatigue performance of the micro and nanometric
Cr3C2-25NiCr coating sprayed by HVOF on ASTM A516 steel substrate
Abstract
NiCr metal matrix composite reinforced with Cr3C2 particles can be
applied as coating to various pieces of equipment, including those
operating under fatigue. In the present study, the nanometric powder was
obtained by high energy milling and sprayed by the high velocity oxygen
fuel technique on ASTM A516 steel substrate. The comparison was made
between the layer obtained from powders in nanometric scale, micrometric
scale and mixing 50% of both. The coating thickness, hardness,
microstructure, porosity and roughness were evaluated. Fatigue tests
were performed on the three coatings in addition to the layer free
substrate. The effect of coating morphology and its roughness on fatigue
performance was studied. The surface roughness of the Nano coating was
significantly lower than both of the other coatings. However, the three
different layers that were tested did not experience significant
differences in their fatigue performance. All three coatings had lower
fatigue performance than the steel substrate.