Browsing by Author "Dominguez-Meister, Santiago"
Now showing 1 - 3 of 3
Results Per Page
Sort Options
Item Electro-tribological properties of diamond like carbon coatings(2019-06-07) Braceras, Iñigo; Ibáñez, Iñigo; Dominguez-Meister, Santiago; Velasco, Xabier; Brizuela, Marta; Garmendia, Iñaki; Tecnalia Research & Innovation; INGENIERÍA DE SUPERFICIESDiamond like carbon (DLC) coatings typically present good self-lubricating tribological properties that could be of interest in sliding dielectric contacts in multiple electrical applications. In this work electro-tribological studies have been performed on several DLC coatings against aluminum in different humidity conditions, in which the coefficients of friction (CoFs) and electrical contact resistance (ECR) were continuously monitored. Results show that CoF and ECR data can be linked to the properties of the coatings (thickness, finishing, microstructure, residual stresses, and wettability) and the degradation modes of their tribological and electrical properties. Therefore, electro-tribological data can provide valuable information about the performance of dielectric coatings, the reasons behind it, and assist in the development of the coatings. ECR also shows potential for on-line monitoring of coated parts in operation.Item Plasma nitriding of the inner surface of stainless steel tubes(2018-12-15) Braceras, Iñigo; Ibáñez, Iñigo; Dominguez-Meister, Santiago; Sánchez-García, Jose Angel; Brizuela, Marta; Larrañaga, Aitor; Garmendia, Iñaki; Tecnalia Research & Innovation; INGENIERÍA DE SUPERFICIESStainless steels, especially the austenitic grades, present a good corrosion resistance but poor mechanical properties. Nitriding can increase the surface hardness but typically at the expense of corrosion resistance. Besides, nitriding of inner surfaces is not straight forward, as control of the plasma there is challenging. This work has focused on the development of active screen plasma nitriding processes of inner geometries of the widely used AISI 316L austenitic stainless steel, with preservation of the corrosion resistance. The structure and composition of the nitrided surfaces were studied and corrosion resistance of the inner surfaces assessed. As a result of the study, a relation has been established between plasma treatment parameters, geometrical features and the corrosion resistance. Additionally, electro-tribological studies have been performed. It has been observed that wear resistance improved and that ECR (Electrical Contact Resistance) is a good indicator of the wear phenomena occurring along the test and potentially could be a useful and simple monitoring tool of the status of the surface and assist in defining safe and dependable operational lives. As part of the study, an equivalent electric circuit is proposed. In conclusion, treatment conditions for AISI316L inner tube surfaces have been defined, with corrosion resistance preservation and improved tribological performance, while ECR monitoring has been found insightful and informative of the evolution of the later.Item Use of smartphones as optical metrology tools for surface wear detection(2021-03) Diamanti, Eleftheria; Iriarte, Eneko; Oblak, Eva; Dominguez-Meister, Santiago; Ibañez, Iñigo; Braceras, Iñigo; Berger, Andreas; Tecnalia Research & Innovation; INGENIERÍA DE SUPERFICIESProper wear level information and early wear detection are crucial goals in many engineering applications and industrial components in order to improve efficiency and reduce production, maintenance, or replacements costs. Furthermore, this should ideally be achieved with a user-friendly, low-cost, and easy to implement methodology for wear level monitoring and detection. In this work, we present the design of a new approach to accomplish early wear detection that is implemented by means of a stand-alone smartphone device and application providing real-time online metrology. The online monitoring is done by means of optical measurements and image processing based on the advanced smartphone vision system technology currently available in commercial devices. The developed mobile App works in continuous mode without interrupting the wear process. Specifically, it traces surface changes and monitors the progression of wear enabling just-in-time warning alarms for “significant wear” and “critical wear” detection. We demonstrate that critical wear of a surface prior to fatal rupture can be detected, which is the main objective in many industrial applications.