Tribological study of NiCrBSi coating obtained by different processes

Thermal spraying offers a wide range of coatings with very different composition and properties. NiCrBSi is a Ni-base superalloy widely used to obtain high wear resistant coatings. This coating is usually heat treated after thermal spraying to improve their tribological properties. In this work a tribological comparison between NiCrBSi coatings obtained by spray&fuse and as-sprayed coatings obtained by Atmospheric Plasma Spraying (APS) and High Velocity Oxy Fuel (HVOF) spraying is carried out. Ball on Disk (BOD) tests are performed with a martensitic plain steel as counterface and wear parameters are calculated by means of Scanning White Light Interferometry (SWLI). Main wear mechanisms are investigated by the characterisation of the coating wear track and debris using Scanning Electron Microscopy (SEM). It is observed that different wear mechanisms take place in the coatings obtained by the diverse processes. (C) 2002 Elsevier Science Ltd. All rights reserved.