Arc sprayed erosion-resistant coating for carbon fiber reinforced polymer matrix composite substrates

Polymer matrix composites (PMCs) are restricted from being widely used in aerospace applications for their low erosion resistance. Arc spray was used to form an erosion-resistant coating for PMC in this paper. A cored wire composed of steel skin and Ni–Cr–B–Si as filler material was used as the coating material. Influence of the pretreatment on the shear bond strength, thermal fatigue resistance, and erosion resistance of the coatings are investigated in this paper. The shear bond strength was as high as 9.4 MPa when the substrate was grit blasted with 28 mesh corundum powder and 0.2 MPa compressed air. Lower pressure of compressed air could be used for fine blasting powder, but the shear bond strength was very low. Much higher blasting pressure would cause damage to the substrate. Sand papers were also used for coarsening the substrate. The shear bond strength of coatings on the samples coarsened with sand papers was lower than that of the samples coarsened by grit blasting with pressure higher than 0.2 MPa. Cracks were found in the 43rd cycle quenching in water of a sample heated to 371 °C, after 50 cycles cooled in air. A soft zinc layer of 100 μm as bond layer could improve a little of the thermal fatigue resistance of the coating. The mass loss of the coated PMC in erosion testing was half of that of the uncoated one, and the arc-sprayed coatings could provide good protection of the PMC from erosion.