José Cabral Miramontes, Gabriela Karina Pedraza Basulto, Citlalli Gaona Tiburcio, Patricia Del Carmen Zambrano Robledo, Carlos Agustín Poblano Salas and Facundo Almeraya Calderón
The thermal spraying technique of High-Velocity Oxygen Fuel (HVOF) coating was used to deposit coatings of an alloy composed of Ni-based substrates on stainless steel AISI 304…
Abstract
Purpose
The thermal spraying technique of High-Velocity Oxygen Fuel (HVOF) coating was used to deposit coatings of an alloy composed of Ni-based substrates on stainless steel AISI 304. The aim of this study was to determine the mechanical properties such as hardness and bond strength that these coatings have when the spray distance is varied, as well as the microstructure and phases formed during the thermal spray process.
Design/methodology/approach
The coatings were applied by HVOF and characterized by scanning electron microscopy, image analysis, X-ray diffraction, microhardness and bond strength to analyze the mechanical properties.
Findings
The microstructure of the coatings showed low porosity, oxide content and interface contamination in the substrate–coating interface, without the presence of unmolten particles. The microhardness values reached 600 HV for the three spray distances used and the bond strength values reached over 55 MPa.
Practical implications
The use of coatings on aircraft components is growing dramatically owing to the high costs of advanced materials and the growing lifecycle requirements for high-performance systems, which are taken into account because of the variety of coatings and complexity of environmental factors.
Originality/value
The originality of this study lies in the development of new coating materials for the manufacture and protection of various turbine components. The value is based on the development of materials and processes to be used to manufacture them.
Details
Keywords
Wilfrido Martinez-Molina, Andres Torres-Acosta, Rosalba Hernández-Leos, Elia Alonso-Guzman, Itzel Mendoza-Pérez and Itandehui Martinez-Peña
The purpose of this paper is to determine if a type of cactus mucilage, Opuntia ficus-indica (OFI), may act as a corrosion inhibitor for carbon steel in cement-based materials…
Abstract
Purpose
The purpose of this paper is to determine if a type of cactus mucilage, Opuntia ficus-indica (OFI), may act as a corrosion inhibitor for carbon steel in cement-based materials (mortar) exposed to chloride-laden environment.
Design/methodology/approach
Mortar prisms, reinforced with carbon steel rods, were immersed in sodium chloride (NaCl) solution for five wet – dry cycles. The experimentation included electrochemical monitoring (corrosion potential, Ecorr, and polarization resistance, Rp) of carbon steel during the time of exposure until corrosion-induced cracking appeared at the mortar surface. Crack survey on the mortar prisms was performed. Carbon steel rods were retrieved from the mortar after crack survey and steel mass loss at the end of the experimental period was estimated. A comparison between the different mixtures was also performed.
Findings
OFI mucilage did perform as a corrosion inhibitor of steel in chloride contaminated mortar.
Research limitations/implications
The experimental program needs to be corroborated in concrete specimens with typical dimensions. The surface oxide/hydroxide formation of the carbon steel in contact with the OFI mucilage is still unknown; thus, electrochemical impedance spectroscopy (EIS) and X-ray diffraction (XRD) analyses are needed.
Practical implications
OFI mucilage is a suitable natural product that can be used to increase durability of concrete structures not only in countries where OFI cactus is produced, but also in many other countries where this plant is considered a plague.
Originality/value
The new information obtained from this paper is the innovative use of a by-product of this cactus plant for construction industry applications.