Finishing MMC coatings in aspect surface roughness reduction and strain hardening
Tomasz Dyl, Robert Starosta, Robert Skoblik 1, 2 Akademia Morska, Wydział Mechaniczny, Katedra Materiałów Okrętowych i Technologii Remontów, ul. Morska 81-87, 81-225 Gdynia, Poland 3 Politechnika Gdańska, Wydział Mechaniczny, Katedra Technologii Materiałów Maszynowych i Spawalnictwa, ul. Narutowicza 11/12, 80-952 Gdańsk, Poland
Quarterly No. 2, 2008 pages 147-151
DOI:
keywords: composite MMC coatings, roughness reduction, strain hardening, finishing of coatings
abstract The composite coatings were obtained by powder flame spraying. The thermal spaying coatings are characterized by great surface roughness. The Ni-Al-Al2O3 coating by finish turning and grinding was processed. The influence of after machining on roughness of coating was estimated. The thermal spraying nickel-based alloy coatings are used in a variety of applications: as bond coats for thermal barrier coatings on turbine components, as restorative layers for machine parts, as bond coats in internal combustion engine cylinders, for corrosion protection of boiler tubes and in numerous other applications requiring wear-, high temperature- and corrosion-resistant surfaces. The composite MMC coatings the development of new specific solutions for each types of engine. Coatings with improved corrosion resistance and abrasion resistance were also developed and are available now. A brief overview on other applications of thermal spraying in the many industry will be given also. The finishing treatment and variables of a treatment process have an effect on quality of machine elements conformance. The finishing treatment allow to obtain awaited properties of the composite MMC coatings and have influence on operation reliability of machine elements. The composite Ni-Al-Al2O3 coatings was machining and plastic working was proposed. Maximum values of the surface roughness reduction ratio for composite Ni-Al-Al2O3 coatings is obtained after rolling and after grinding. The coating subjected to cold plastic working gained a more homogeneous structure as most of the pores, which had occurred after flame spraying and after machining, were closed.