Microstructure and adhesive-cohesive strenght of nickel, tungsten carbide and chromium oxide thermal spray coatings
Journal Title: TecnoLógicas - Year 2016, Vol 19, Issue 36
Abstract
Four thermal spray coatings were applied by oxy-fuel process onto ASTM A743 CA6NM (13Cr-4Ni) steel, namely: two Ni-rich alloys, a chromium oxide and a combined tungsten carbide/Ni-Cr particles coating. The microstructure and adhesive/cohesive strength of the coatings were studied and related to the surface preparation parameters (preheating temperature and surface roughness). The microstructures were studied by XRay diffraction (XRD), scanning electron (SEM) and light optical (LOM) microscopy and hardness was measured according to ASTM E384 standard. The adhesive/cohesive strength was measured according to ASTM C633 standard. The microstructure of the coatings showed porosity (8% for bond coatings and from 15 to 30% for ceramic coatings) within acceptable values for flame spraying Homogeneous coating thicknesses of circa 0.5 mm were obtained. Adhesive strength was among 10 to 19 MPa for most of coatings. The coating-substrate adhesive strength was satisfactory in most cases and significant variations (higher than 25%) in adhesive/cohesive strength were induced by changes in surface preparation parameters, especially in the case of WC/Co-Ni coating.
Authors and Affiliations
Juan F. Santa-Marín, Alejandro Toro-Betancur
Keywords
Related Articles
- EP ID EP401817
- DOI 10.22430/22565337.592
- Views 88
- Downloads 0
Feature extraction based on time-singularity multifractal spectrum distribution in intracardiac atrial fibrillation signals
Non-linear analysis of electrograms (EGM) has been proposed as a tool to detect critical conduction sites (e.g., rotors vortex, multiple wavefronts) in atrial fibrillation (AF). Likewise, studies have...
Influence of the bed height on the dynamic behavior of a fixed-bed column during mercury biosorption
This study evaluated the packing density of residual biomass of cocoa bean husk as adsorbent of Hg (II) dissolved in an aqueous solution inside a continuous fixed-bed system. The effects of the height o...
Changes in the bioactive compounds of pasteurized gooseberry (Physalis peruviana L.) juice
The worldwide market of fruit drinks is interested in exotic juices with high nutritional value, and part of that demand can be satisfied with gooseberry derivatives. Therefore, the objective of this study was to evaluat...
Thermal behavior evaluation of solar dryers in a passive regime
This article presents the evaluation of the thermal behavior of three solar dryers in a passive flow regime designedfor the environmental conditions of the Colombian Caribbean Coast. Field experiments we...
Behaviour of surge arresters against lightning-induced voltages on distribution lines over mountainous zones
This paper analyzes how the location of surge arresters on distribution lines over mountainous zones affect the lightning-induced voltages in this kind of lines. Four configurations of non-flat terrains representative of...