Evaluation of scratch resistant properties of electroless Ni-P-Al2O3 composite coatings

Evaluation of scratch resistant properties of electroless Ni-P-Al2O3 composite coatings

Ni-P-Al2O3 composite coatings were prepared from electroless plating method on copper substrate with different contents ofAl2O3 powder. Thus obtained composite coatings were heat treated at 400 oC for 1 h in an inert environment and subjectedto scratch tests. Compared to Ni-P coating, codeposition of Al2O3 exhibited the nodular structure and slightly increased surfaceroughness of the composite coatings. Low P nickel coating with approximately 4 wt% of codeposited Al2O3 into the depositwas obtained with 10 g/L Al2O3 concentration into the plating bath. Enhanced Vickers microhardness of the composite coatingwas due to the synergistic effects of the precipitation hardening by Ni3P phase and co-deposited hard Al2O3 particles. Furthermore, Ni-P-Al2O3 composite coatings have shown considerable improvement in load-bearing capacity of the coatingmatrix, thereby, enhancing the scratch resistant properties of the composite coating.

Ni-P-Al2O3 composite coatings were prepared from electroless plating method on copper substrate with different contents ofAl2O3 powder. Thus obtained composite coatings were heat treated at 400 oC for 1 h in an inert environment and subjectedto scratch tests. Compared to Ni-P coating, codeposition of Al2O3 exhibited the nodular structure and slightly increased surfaceroughness of the composite coatings. Low P nickel coating with approximately 4 wt% of codeposited Al2O3 into the depositwas obtained with 10 g/L Al2O3 concentration into the plating bath. Enhanced Vickers microhardness of the composite coatingwas due to the synergistic effects of the precipitation hardening by Ni3P phase and co-deposited hard Al2O3 particles. Furthermore, Ni-P-Al2O3 composite coatings have shown considerable improvement in load-bearing capacity of the coatingmatrix, thereby, enhancing the scratch resistant properties of the composite coating.