FORMATION OF COMPOSITE COATING «NICKEL-SILICON CARBIDE»

Abstract

The influence of processed sample position relative to the equipment bottom and electrolyte mixingspeed during an electrochemical processing aluminum alloy AK7 samples surface on a formed metalmatrix composite coating «Ni+SiC» quality was considered. It has been shown that the compositecoating microstructure formed in a glass container under the horizontal sample positioned witha minimum mixing speed and in a vertical equipment with the automatic stirring possibility hassignificant differences. The quality of the «Ni+SiC» composite coating is determined by the positionof the sample being processed relative to the bath bottom and the electrolyte speed mixing. With ahorizontal sample position and minimal electrolyte mixing speeds, a composite nickel coating is beingformed with a uniform distribution of strengthening SiC particles with a volume fraction of 24%, arough surface and single pores. With a vertical position and high electrolyte mix speeds, a coatingis being formed with a volume strengthening particles fraction of 2% and a smooth surface withoutpores. It is proposed to develop a horizontal-vertical equipment for electrodeposition, allowing stablyproduce a «Ni+SiC» composite coating with a uniform strengthening particles distribution and aminimal roughness based on the obtained results.