Multi-components composite coating for increase corrosion resistance of thermally sprayed coatings
The material-technological concepts of obtaining the multilayer composite structure of coatings for high temperature application are presented. The ceramic-inorganic and polymer coatings are the surface materials for the modification of the thermally sprayed coatings. The chemical, phase composition and structure of composite coatings with phosphate sealing and ceramic particles are presented. The corrosion protection of coatings is determining by thermal sprayed coatings and modified surface multilayered composition with ceramic phases. The industry application of presented materials is shown.
Key words: composite coating, ceramic sealing, multilayer structure, thermal spraying
Regulation of European Commission documents referring to corrosion protection in industry and building engineering
Regulatory requirements resulting from European Committee documents and applying to construction products were represented with a special consideration products used as a protection of building structure. National assessment system of products used as a protection of steel, aluminium, concrete and wooden constructions as well as principles of bringing products onto the market have been discussed. National requirements according to ITB actions taken for EOTA (European Organisation for Technical Approvals) and works made for engineers responsible for corrosion protection have been presented.
Key words: technical approvals, EOTA, building law, technical recommendation, construction products, corrosion protection
The influence of thermal spraying parameters on the metal coating costs
The test results of the influence of spraying distance, metal type and atomizing chamber type in arc spraying gun on materials loss (it means also costs and time) are discussed. Tests were carried out according to PN-EN ISO 17836. It has Bern fund that too big spraying distance could increase material costs even twice. Use of Zn-Al alloy instead of Zn could decrease the costs of about 10–12%. The importance of atomizing system was underlined.
Key words:thermally sprayed coating, spraying efficiency factor, material loss, spraying distance, coating adhesion
The structure of Zn5Al3Cu coatings after corrosion examinations
The paper presents results of investigations of the surface state of the Zn5Al3Cu coatings, obtained by the high temperature zinc plating, after corrosion examinations. The structural examinations before corrosion tests were performed. Then investigations of the surface state of samples after potentiostatic tests (12 h) in 3% NaCl were performed. The completed tests showed that examined coatings present eutectic structure. All samples showed good corrosion resistance. The obtained results show that the corrosion of Zn5Al3Cu coatings runs after borders of crystallites.
Key words: electrochemical corrosion, Zn-Al-Cu coatings, structure