Preparation Conditions Of Aluminum/Iron Oxide Waterborne Pigments And Its Influence On Color,Corrosion Resistance And Stealth Performance

As one of the most important metallic pigments,aluminum flakes has been widely used in solvent-based paints and ink industry.Its highly reflective of light and low emission characteristics,which make aluminum powder can be used as infrared camouflage paint.Meanwhile,as the enhancements of environment awareness,preparations of waterborne aluminum pigment become a research hotspot.But the color of aluminum pigment was still silver,which cannot meet the requirement of the visible range of the infrared stealth.In this paper,the colorful waterborne aluminum pigments were prepared by wet chemical deposition method using H₂O₂ as anchoring agent and FeC l3·6H2O or FeSO₄·7H₂O as precursor.In this paper,samples were characterized by hyd rogen test,optical microscopy,scanning electron microscope,multi-angle spectrophotometer,X-ray diffraction,infrared spectrum,thermogravimetric analysis.The main contents were as following:1.In acidic conditions,H₂O₂ could oxidation aluminum forming diaspore as anchor point.With the increase of coating medium pH,the diaspore on the aluminum surface decreased,and the boehmite hydroxy aluminum increased.2.In the FeSO₄·7H₂O system and low p H conditions,diaspore could be induced greenrust forming goethite coating layer.As the pH increased,the iron oxide prefers to form greater particle rather than form a coating layer,which lead to a poor performance.At the condition of p H5.0 and temperature 45 °C,the supersaturation of solution was suitable to forming goethite coating layer,but the highly reflective was not suit for stealth pigment.3.In the FeCl₃·6H₂O system and high pH conditions,boehmite and ferrihydrite forming a dense coating layer with good anticorrosion property.At p H 6.5,prepared khaki pigment which was suitable for stealth material.Though the low anchorage efficiency,the competitive of coating was high,the samples corrosion resistance were higher than samples coated with FeSO₄·7H₂O.This topic discussed the condition,which was effect the anchorage efficiency on the aluminum surface of Fe3+ or Fe2+ salt,and studies the coating mechanism.The investigation results provide theoretical basis for obtain infrared stealth aluminum pigments.