STUDY OF THE EFFECT OF THE ELECTROLESS NI-P COATING THICKNESS APPLIED ON AW-7075 ALUMINUM ALLOY ON ITS MECHANICAL PROPERTIES

The paper presents the results of examination of microhardness of chemical coatings Ni-P, applied on samples of aluminium alloy for plastic processing AW-7075. The examinations have been performed on samples with three different thicknesses of the Ni-P coatings; next the influence of their thickness on the depth of material penetration by the indenter under load, as well as its influence on creep, increase of Martens hardness and on the Young's modulus of the system of the coating with the substrate material. Hardness measurements have been performed with the use of PICODEN-TOR HM500 nanohardness tester (Vickers). The purpose of the examination of Ni-P coating deformation without dispersion phases is analysis of their mechanical properties in respect of the possibility of technical applications on the aluminium alloy AW-7075 (among others, by the selection of optimum thicknesses on hard aluminium alloy), as well as the determination of the possibility of applying dispersion phases in order to improve their properties.