Statistical Eloxal Coating Microhardness Analysis

Abstract

In order to improvethe mechanical properties ofthe excludedlayer by anodic oxidationof aluminum on material EN AW-1050 H24, there wasinvestigated the micro-hardness ofexcludedlayeras a function ofphysical and chemical factorsinvolved inthe anodicoxidationprocess. The constantcurrent density wasJA= 3A.dm -2 in the electrolyte,constituted bysulfuric acidandoxalic acid. The emphasis was put on the impact of allconsideredactive factors and theirinteractions in this process. The model of studied dependence was designedbasedonmathematical andstatistical analysis ofmatrix with experimentalobtained data of compositerotation plan of experimentwith fiveindependentvariablesfactors (amount of sulfuric acid in the electrolyte, amountof oxalic acidin the electrolyte, temperature of electrolyte, anodizingtimeand appliedvoltage). Theexperimentwascarried out on 44 separateattempts withcurrent change of values of individualfactors underdefined levels in eachimplementation.