Axial suspension plasma spraying of Al2O3 coatings for superior tribological properties

Abstract Suspension plasma spray is a relatively new thermal spray technique which enables feeding of fine powder to produce advanced coatings for varied applications. This work investigates the difference in structure and performance of Al2O3 coatings manufactured using conventional micron-sized powder feedstock and a suspension of sub-micron to few micron sized powder. Axial injection was implemented for deposition in both cases. The effect of feedstock size and processing on the tribological performance of the two coatings was of specific interest. The coatings were characterized by Optical and Scanning Electron Microscopy, micro-hardness and scratch resistance testing, and their dry sliding wear performance evaluated. The suspension sprayed coatings yielded significantly higher scratch resistance, lower friction coefficient and reduced wear rate compared to conventional coatings. The improved tribological behaviour of the former is attributable to finer porosity, smaller splat sizes, and improved interlamellar bonding.

[1]  Leon L. Shaw,et al.  Development and implementation of plasma sprayed nanostructured ceramic coatings , 2001 .

[2]  R. Jayaganthan,et al.  A study on sliding and erosive wear behaviour of atmospheric plasma sprayed conventional and nanostructured alumina coatings , 2011 .

[3]  Qinghe Yu,et al.  Thermal properties of plasma-sprayed thermal barrier coating with bimodal structure , 2011 .

[4]  P. Fauchais,et al.  Effect of the Structural Scale of Plasma-Sprayed Alumina Coatings on Their Friction Coefficients , 2008, International Thermal Spray Conference.

[5]  L. Pagnotta,et al.  Microstructural, mechanical and tribological properties of nanostructured YSZ coatings produced with different APS process parameters , 2015 .

[6]  I. Hutchings,et al.  An optical method for assessing scratch damage in bulk materials and coatings , 2003 .

[7]  Lech Pawlowski,et al.  Finely grained nanometric and submicrometric coatings by thermal spraying: A review , 2008 .

[8]  M. Vardavoulias,et al.  A Comparative Microstructural Investigation of Nanostructured and Conventional Al2O3 Coatings Deposited by Plasma Spraying , 2008, International Thermal Spray Conference.

[9]  S. Guessasma,et al.  Note on POD test parameters to study wear behaviour of alumina–titania coatings , 2004 .

[10]  Ghislain Montavon,et al.  Dry Sliding Behavior of Sub-Micrometer-Sized Suspension Plasma Sprayed Ceramic Oxide Coatings , 2009, International Thermal Spray Conference.

[11]  S. Langner,et al.  Comparison of the Microstructural Characteristics and Electrical Properties of Thermally Sprayed Al2O3 Coatings from Aqueous Suspensions and Feedstock Powders , 2012, Journal of Thermal Spray Technology.

[12]  C. Berndt,et al.  IFTHSE Global 21: heat treatment and surface engineering in the twenty-first century Part 10 – Thermal spray coatings: a technology review , 2010 .

[13]  C. Coddet,et al.  Nanostructured photocatalytic titania coatings formed by suspension plasma spraying , 2006 .

[14]  C. Berndt,et al.  Bimodal distribution of mechanical properties on plasma sprayed nanostructured partially stabilized zirconia , 2002 .

[15]  V. Racherla,et al.  Mechanical properties of conventional and nanostructured plasma sprayed alumina coatings , 2012 .

[16]  R. Wüthrich,et al.  Three-dimensional electrode coatings for hydrogen production manufactured by combined atmospheric and suspension plasma spray , 2016 .

[17]  Stefan Björklund,et al.  Characterization of Microstructure and Thermal Properties of YSZ Coatings Obtained by Axial Suspension Plasma Spraying (ASPS) , 2015, Journal of Thermal Spray Technology.

[18]  M. Gupta.  Design of Thermal Barrier Coatings: A Modelling Approach , 2015 .

[19]  Yulei Wang,et al.  Three body abrasive wear characteristics of plasma sprayed conventional and nanostructured Al2O3-13%TiO2 coatings , 2010 .

[20]  Basil R. Marple,et al.  Thermal Spray Coatings Engineered from Nanostructured Ceramic Agglomerated Powders for Structural, Thermal Barrier and Biomedical Applications: A Review , 2007 .

[21]  B. Bonferroni,et al.  Wear behaviour of high velocity suspension flame sprayed (HVSFS) Al2O3 coatings produced using micron- and nano-sized powder suspensions , 2010 .

[22]  Vijay Kumar,et al.  Processing and design methodologies for advanced and novel thermal barrier coatings for engineering applications , 2016 .

[23]  Nicolaie Markocsan,et al.  Influence of Microstructure on Thermal Properties of Axial Suspension Plasma-Sprayed YSZ Thermal Barrier Coatings , 2015, Journal of Thermal Spray Technology.

[24]  R. Gadow,et al.  Microstructural and Tribological Investigation of High-Velocity Suspension Flame Sprayed (HVSFS) Al2O3 Coatings , 2009 .

[25]  L. Shaw,et al.  Indentation fracture behavior of plasma-sprayed nanostructured Al2O3-13wt.%TiO2 coatings , 2003 .

[26]  E. Lugscheider,et al.  A comparative study on thermally sprayed alumina based ceramic coatings , 2000 .

[27]  C. Berndt,et al.  Scratch testing and acoustic emission of nanostructured partially stabilized zirconia , 2013 .

[28]  N. H. Saad,et al.  Impact of Plasma Spray Variables Parameters on Mechanical and Wear Behaviour of Plasma Sprayed Al2O3 3%wt TiO2 Coating in Abrasion and Erosion Application , 2012 .

[29]  S. Langner,et al.  Microstructures and Functional Properties of Suspension-Sprayed Al2O3 and TiO2 Coatings: An Overview , 2010 .

[30]  H. M. Hawthorne,et al.  Cohesion in plasma-sprayed coatings : a comparison between evaluation methods , 1998 .

[31]  P. Xiao,et al.  A comparative study on the performance of suspension plasma sprayed thermal barrier coatings with different bond coat systems , 2015 .

[32]  M. Geetha,et al.  Sliding wear behavior of plasma sprayed nanoceramic coatings for biomedical applications , 2011 .

[33]  G. Bertrand,et al.  Microstructure and tribological behavior of suspension plasma sprayed Al2O3 and Al2O3―YSZ composite coatings , 2010 .

[34]  Basil R. Marple,et al.  Nanostructured YSZ thermal barrier coatings engineered to counteract sintering effects , 2008 .

[35]  P. Bandyopadhyay,et al.  Scratch induced failure of plasma sprayed alumina based coatings , 2012 .

[36]  T. Chartier,et al.  Suspension Plasma-Sprayed Alumina Coating Structures: Operating Parameters Versus Coating Architecture , 2008, International Thermal Spray Conference.

[37]  Guilan Wang,et al.  Fabrication and electrochemical performance of solid oxide fuel cell components by atmospheric and suspension plasma spray , 2009 .