Heat Treatment Effect on Properties of Ni-P-Al2O3 Composite Coatings
-
- DOI: https://doi.org/10.1557/PROC-1243-6
- Published online by Cambridge University Press: 01 February 2011
Abstract
Ni-P and Ni-P-Al2O3 composite coatings are obtained by electroless plating on steel substrates. Alumina particles with an average particle size of 5 microns are added to the bath in loads of 5, 10, 15 and 20g/L. It is found a maximum retention of 18.2 vol.% Al2O3 for a ceramic load of 10g/L. The composition of the binary Ni-P deposits is 9.3 wt.% P and the balance nickel. The addition of ceramics to the electroless solution induces a reduction of phosphorous content to 9.0, 8.3, 7.9 and 7.3%, respectively. The deposited coatings are heat-treated in the temperature range between 100 and 500°C and holding times from 30 to 300 minutes. A maximum hardness of 1600 HV0.1 is obtained for composite coatings containing 18.2 vol.% Al2O3 treated at 400 °C/1h. The uniform distribution of ceramics and precipitation of fine Ni3P and Ni12P5 precipitates are responsible of the hardening of the nickel matrix.
Copyright
References
Heat Treatment Effect on Properties of Ni-P-Al2O3 Composite Coatings
-
- DOI: https://doi.org/10.1557/PROC-1243-6
- Published online by Cambridge University Press: 01 February 2011