Evaluation of the Adhesion and Slurry Wear Erosion of Nb 2 O 5 Coatings Applied by Flame Spray
- PDF / 2,462,245 Bytes
- 11 Pages / 593.972 x 792 pts Page_size
- 12 Downloads / 243 Views
ODUCTION
INDUSTRIAL equipment operating in aggressive environments has wear as an undesirable problem, which provokes serious technical and economic consequences.[1] The use of coatings can increase the life of components, reducing the cost of replacement and maintenance of parts. Research and development in coatings science and surface technology is driven by an increase in industry requirements for high-performance coatings at a relatively low cost. Additionally, there is an increasing regulatory pressure to reduce hazardous waste, such as hexavalent chromium and organic compound volatiles, which are eventually produced by coating processes and can generate environmental pollution.[2] Niobium pentoxide (Nb2O5) is a material that can be used as a protective coating, increasing the protection of MARIA JU´LIA XAVIER BELE´M and CARLOS ROBERTO CAMELLO LIMA are with the Production Engineering Graduate Program, Methodist University of Piracicaba, Piracicaba, SP 13451900 Brazil. Contact e-mail: [email protected] HIPO´LITO CARVAJAL FALS and ANGEL SANCHEZ ROCA are with the College of Mechanical and Industrial Engineering, Oriente University, CP 90900 Santiago de Cuba, Cuba. Manuscript submitted February 26, 2019. Article published online September 25, 2019 METALLURGICAL AND MATERIALS TRANSACTIONS A
industrial equipment and contributing to cost reduction, thus reducing the need to repair damages caused by corrosion and wear processes.[3] In addition to high availability, Nb2O5 offers health and environmental safety, as can be seen in the REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) regulation, which states that this material presents no particular hazard, unlike traditional materials, such as cobalt (Co) and tungsten carbide (WC), most frequently used in the protection against wear. WC and Co give rise to a spectrum of risks and health problems caused by the formation of tungsten trioxide (WO3) and tricobalt (Co3O4) tetroxide on WC and Co surfaces by oxidation or tribo-oxidation released into the environment by means of particles that are released during the wear process.[4] WO3 and Co3O4 have received classifications and labels notified under the REACH regulation with risks to human health.[4,5] In this context, Nb2O5 can be considered a promising material to protect the substrate from a hostile environment, presenting economic and environmental advantages. Nb2O5 has unique chemical and physical characteristics, such as high chemical stability, phase-dependent properties, and high corrosion resistance, in acidic and alkaline media,[6,7] besides presenting electronic and optical properties, which allow its application in gas
VOLUME 50A, DECEMBER 2019—5877
sensors,[8] in electrochromic devices,[9–11] in solar cells,[9,12,13] optical devices,[14,15] and as catalysts.[16] Nb2O5 is one of the main niobium oxides, exhibiting resistance to corrosion and wear,[17,18] thermodynamic stability, and biocompatibility,[19] extending engineering applications for use as a biomaterial.[20] Several methods of
Data Loading...
