Temperature can have a significant effect on the extent of wear damage of metallic
components. Thermal barrier coatings with MCrAlY (where M=Ni, Co, Fe or
combinations) alloys can improve the high temperature tribological and friction wear
behaviour. In this work the dry friction and wear behaviour at room temperature and
high temperature of new developed NiCoCrAlY and CoNiCrAlY laser cladding
coatings were evaluated. Dense coatings, with good metallurgical bonding to the AISI
304 substrate was obtained by coaxial laser cladding tracks (40% overlapping), with
previously optimized laser parameters. Tribological tests were performed by sliding
wear at room temperature and 500 ºC, with an Al2O3 counterpart in ball on disk
configuration tribometer. The wear scar surface was evaluated by scanning electron
microscopy (SEM) and energy dispersive spectroscopy (EDS) microanalysis. The 3D
wear track topography was measured by inductive contact profilometer which
enabled the wear rate calculation. The microstructure of the coatings consists of -
Ni/-NiAl or -Co/-(Co,Ni)Al phases depending on the chemical composition of the
alloy, as confirmed by X-ray diffraction (XRD) analysis. The wear test results show a
reduction in wear rate at high temperature for all materials tested. For the NiCoCrAlY
coating, the high temperature also reduces the friction coefficient, while it significantly
increases the friction coefficient of CoNiCrAlY coating. The main damage mode is
abrasion and adhesion, caused by oxides and partially-oxidized particles in the
contact surface. The coatings and substrate results were compared, resulting in
improved wear behaviour.The authors acknowledge the financial support of the Ministry of Science and
Innovation of the Government of Spain through research project MAT2011-28492-
C03 and the Generalitat Valenciana through ACOMP/2013/114 support. Professor Juan Carlos Pereira Falcón thanks the University of Carabobo for the financial
support to pursue his doctoral studies at the UPV
