Open Access
Improvement of the tribocorrosion properties of cemented carbide (WC-Tic-Co) samples with PVD coating
(MDPI, 2022) García Lorente, José Antonio; Claver Alba, Adrián; Marques, Mikel; Almandoz Sánchez, Eluxka; Fernández de Ara, Jonathan; Azkona, Ibon; Institute for Advanced Materials and Mathematics - INAMAT2
This study aims to investigate the improvement of the tribocorrosion properties of WC-TiC-Co substrates by coating them with hard coatings such as AlCrSiN using cathodic arc deposition. WC-TiC-Co is commonly used in the fabrication of machining and cutting tools; however, there are some materials such as titanium or stainless steel that are difficult to work with; furthermore, in aggressive environments or under high temperatures the performance of the machining tools can be affected, and a failure may occur. This coating is intended to ensure the correct performance of the tools in any conditions. The coatings were characterized by glow discharge optical emission spectroscopy (GDOES), scanning electron microscopy (SEM) and X-ray diffraction (XRD). Tribocorrosion, tribology and corrosion tests were performed to evaluate the tribocorrosion properties of the samples. Furthermore, mechanical and adhesive properties of the coating were studied using scratch and nanoindentation tests. The results showed improved tribocorrosion properties in the samples combined with good adhesive and mechanical properties. These results show the possibility of using these coated materials in the most demanding cutting and machining applications.
Open Access
Influence of friction coefficient on the performance of cold forming tools
(MDPI, 2023) Barba Areso, Eneko; Salcedo Pérez, Daniel; Claver Alba, Adrián; Luri Irigoyen, Rodrigo; García Lorente, José Antonio; Ingeniería; Ingeniaritza
The automotive industry has undergone significant advancements and changes over time, resulting in the use of more complex parts in modern vehicles. As a consequence, the parts used in the manufacturing process are subject to higher stress levels, which reduce their service life. To mitigate this issue, surface treatments can be applied to improve the mechanical properties of the tools. In this study, we examined the impact of surface treatments on reducing tool stress during a cold forming process. The process involved reducing the thickness of a sheet from 6 mm to 2.5 mm, which generated high stresses in the tooling. We used finite element stress calculations to analyze the process and found that by reducing the friction coefficient to 0.1, tool stresses can be reduced by 20%, leading to an increase in tool life. Moreover, the press force and tool wear were also reduced by 18%. To validate the theoretical calculations, we performed field tests in a real manufacturing process.
Open Access
Study and optimization of the punching process of steel using the Johnson-Cook damage model
(MDPI, 2024) Claver Alba, Adrián; Hernández Acosta, Andrea; Barba Areso, Eneko; Fuertes Bonel, Juan Pablo; Torres Salcedo, Alexia; García Lorente, José Antonio; Luri Irigoyen, Rodrigo; Salcedo Pérez, Daniel; Ingeniería; Ingeniaritza; Institute for Advanced Materials and Mathematics - INAMAT2
Sheet metal forming processes are widely used in applications such as those in the automotive or aerospace industries. Among them, punching is of great interest due to its high productivity and low operating cost. However, it is necessary to optimize these processes and adjust their parameters, such as clearance, shear force or tool geometry, to obtain the best finishes and minimize crack generation. Thus, the main objective of this research work is to optimize the punching process to achieve parts that do not require subsequent processes, such as deburring, by controlling the properties of the starting materials and with the help of tools such as design of experiments and simulations. In the present study, tensile tests were performed on three steels with different compositions and three sample geometries. The information obtained from these tests has allowed us to determine the parameters of the Johnson-Cook damage criteria. Moreover, punching was performed on real parts and compared with simulations to analyze the percentage of burnish surface. The results obtained show that the methodology used was correct and that it can be extrapolated to other types of die-cutting processes by reducing the percentage of surface fractures and predicting the appearance of cracks. Furthermore, it was observed that clearance has a greater influence than processing speed, while the minimum percentage of the burnish area was observed for the minimum values of clearance.
Open Access
Comparative study of tribomechanical properties of HiPIMS with positive pulses DLC coatings on different tools steels
(MDPI, 2021) Claver Alba, Adrián; Jiménez-Piqué, Emilio; Almandoz Sánchez, Eluxka; Fernández de Ara, Jonathan; Fernández, Iván; Santiago, José A.; Barba Areso, Eneko; García Lorente, José Antonio; Ingeniaritza; Institute for Advanced Materials and Mathematics - INAMAT2; Ingeniería
Diamond-like carbon (DLC) coatings are very interesting due to their extraordinary properties; their excellent wear resistance, very low friction coefficient, great hardness, high elastic modulus or biocompatibility can be highlighted, as can their multifunctionality. Because of this, over recent decades they have been widely used in tribological applications, improving the performance and the useful life of machining tools in an effective way. However, these coatings have a disadvantage compared to other coatings deposited by commercially available techniques-their resultant adhesion is worse than that of other techniques and limits their industrial applications. In this work, tribological results of a scratch test, wear resistance and nanoindentation of tetrahedral amorphous carbon (ta-C) and tungsten carbide:carbon (WC:C) DLC coatings deposited by means of novel highpower impulse magnetron sputtering (HiPIMS) technology with positive pulses are reported. The coatings were deposited in three different tools steels: K360, vanadis 4 and vancron. These tools' steels are very interesting because of their great and wide industrial applicability. Experimental results showed excellent tribological properties, such as resistance to wear or adhesion, in the two types of DLC coatings.
Open Access
Biodegradable magnesium alloys for personalised temporary implants
(MDPI, 2023) Hendea, Radu Emil; Raducanu, Doina; Claver Alba, Adrián; García Lorente, José Antonio; Cojocaru, Vasile Danut; Nocivin, Anna; Stanciu, Doina; Serban, Nicolae; Ivanescu, Steliana; Trisca-Rusu, Corneliu; Campian, Radu Septimiu; Institute for Advanced Materials and Mathematics - INAMAT2
The objective of this experimental work was to examine and characterise the route for obtaining demonstrative temporary biodegradable personalised implants from the Mg alloy Mg10Zn-0.5Zr-0.8Ca (wt.%). This studied Mg alloy was obtained in its powder state using the mechanical alloying method, with shape and size characteristics suitable for ensuing 3D additive manufacturing using the SLM (selective laser melting) procedure. The SLM procedure was applied to various processing parameters. All obtained samples were characterised microstructurally (using XRD—Xray diffraction, and SEM—scanning electron microscopy); mechanically, by applying a compression test; and, finally, from a corrosion resistance viewpoint. Using the optimal test processing parameters, a few demonstrative temporary implants of small dimensions were made via the SLM method. Our conclusion is that mechanical alloying combined with SLM processing has good potential to manage 3D additive manufacturing for personalised temporary biodegradable implants of magnesium alloys. The compression tests show results closer to those of human bones compared to other potential metallic alloys. The applied corrosion test shows result comparable with that of the commercial magnesium alloy ZK60.
Open Access
Study of the industrial application of diamond-like carbon coatings deposited on advanced tool steels
(MDPI, 2024) Barba Areso, Eneko; Claver Alba, Adrián; Montalá, Francesc; Luis Pérez, Carmelo Javier; Sala, Neus; Colominas, Carles; García Lorente, José Antonio; Ingeniería; Ingeniaritza
The utilization of diamond-like carbon (DLC) coatings has emerged as a promising strategy to enhance the performance, durability, and functionality of industrial tools and components. Recognized for their exceptional attributes such as hardness, wear resistance, low friction, and biocompatibility, DLC coatings have achieved widespread acclaim for their potential to improve the capabilities of tool steels for different applications. This present study shows a comprehensive investigation into the application of DLC coatings on a diverse range of tool steel substrates, encompassing 1.2379, 1.2358, Caldie, K340, HWS, and Vanadis 4. The main aim is to show the effects of DLC coatings on these substrates and to provide an in-depth analysis of their properties during forming processes. Furthermore, this study explores the practical utilization of DLC-coated tool steel components, with a particular focus on their role in cold forming dies. Additionally, the study reviews the application of duplex treatments involving plasma nitriding to enhance DLC coating performance. To sum up, this study pursues a threefold objective: to investigate DLC coatings’ performance on diverse tool steel substrates; to assess the potential for improvement through nitriding; and to evaluate the behavior of DLC coatings in the cold stamping of S235 steel, which is of great technological and industrial interest to the cold forging sector.
Open Access
Improved adhesion of the DCL coating using HiPIMS with positive pulses and plasma immersion pretreatment
(MDPI, 2021) Gómez Alonso, Íñigo; Santiago, José A.; Fernández, Iván; Diaz, Cristina; Mändl, Stephan; García Lorente, José Antonio; Claver Alba, Adrián; Ingeniaritza; Institute for Advanced Materials and Mathematics - INAMAT2; Ingeniería; Gobierno de Navarra / Nafarroako Gobernua, 0011-1408-2018-000000
Diamond-like carbon (DLC) coatings are used due to their extraordinary tribomechanical properties, great hardness, high elastic modulus, high wear resistance, low friction coefficient and chemical inertness, which provide them with biocompatibility. Compared to other physical vapor deposition (PVD) coatings of transition nitrides and carbonitrides, DLC has limited adhesion, so it is necessary to develop new techniques to overcome this limitation. This work reports the results of scratch testing for the measurement of adhesion and of tests for wear resistance and nanoindentation in AISI 316L stainless steel coated with a WC:C coating, produced using novel high-power impulse magnetron sputtering (HiPIMS) technology with positive pulses. In addition, the use of a preceding surface modification technique, specifically plasma immersion ion implantation (PIII), was studied with the aim of optimizing the adhesion of the coating. The results show how the coating improved the tribomechanical properties through the use of positive pulse HiPIMS compared to conventional HiPIMS, with an adhesion result that reached critical load values of 48.5 N and a wear coefficient of 3.96 × 10−7 mm3/nm.
Open Access
Improved adhesion and tribological properties of altin-tisin coatings deposited by dcms and hipims on nitrided tool steels
(MDPI, 2021) Claver Alba, Adrián; Randulfe Ceballos, Jesús José; Fernández de Ara, Jonathan; Almandoz Sánchez, Eluxka; Montalá, Francesc; Colominas, Carles; Cot, Víctor; García Lorente, José Antonio; Ingeniaritza; Institute for Advanced Materials and Mathematics - INAMAT2; Ingeniería
Hard coatings, such as AlTiN-TiSiN, deposited by Physical Vapor Deposition (PVD) techniques are widely used in industrial applications to protect and increase the lifetime of industrial components, such as cutting tools, dies, and forming tools. Despite their great properties, such as high hardness and wear and oxidation resistance, they are limited in cases of severe conditions due to the poor adhesion between the coating and the substrate. Duplex treatments have commonly been used to improve the adhesive properties of PVD coatings, especially those of the cathodic arc evaporation type. The purpose of this study is to achieve coatings with the good properties of the Magnetron Sputtering processes but with higher adhesion than that achieved with these techniques, thus achieving coatings that can be used under the most severe conditions. In this work, an AlTiN-TiSiN coating was deposited by a combination of DC Magnetron Sputtering (DCMS) and High-Power Impulse Magnetron Sputtering (HiPIMS) after a gas nitriding pretreatment on 1.2379 and Vanadis 4 tool steels. Mechanical (ultra-microhardness and scratch tests) and tribological tests were carried out to study the improvement in the properties of the coating. Duplex-treated samples showed improved adhesion between the coating and the substrate, with second critical load (Lc2) values greater than 100 N. Furthermore, they showed great toughness and wear resistance. These results show that this type of coating technique could be used in the most extreme applications and that they can compete with other techniques and coatings that to date they have not been able to compete with.
Open Access
Recycling bovine ear tags for phase change material encapsulation via electrospinning
(Elsevier, 2025-10-01) Alfonso de Miguel, Iker; Calvo-Correas, Tamara; Eceiza, Arantxa; Claver Alba, Adrián; Torresi, Stefano; García Lorente, José Antonio; Zalakain Iriazabal, Iñaki; Ingeniería; Ingeniaritza; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
In this study, thermoplastic polyurethane (TPU) from waste bovine ear tags has been processed and recycled as shell material to encapsulate phase change materials (PCMs), enabling the fabrication of thermoregulating core-shell nanofibers via coaxial electrospinning. Notably, this process was achieved in few steps and without the need for heating equipment to melt the injected materials, enhancing its simplicity. Two PCMs were selected based on their melting points; octadecane (OCTA) near room temperature and eicosane (EICO) near body temperature. Composite fibers were prepared at different core solution concentrations (10, 20, 40 and 80 % w/v), with the highest encapsulation efficiency and thermal properties obtained for samples with 80 % (w/v). TPU/PCM electrospun nanofibers were observed by scanning electron microscopy (SEM) with average diameters between 400 and 700 nm. The Fourier transform infrared spectroscopy (FTIR) suggested no further chemical reactions during the fabrication process. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) demonstrated good thermal stability, with latent heats of 62.9 2 J/g and 81.4 J/g for TPU/OCTA80 and TPU/EICO80 membranes, respectively. Thermal cycling tests were conducted for 150 cycles, showing a 5 % enthalpy reduction in TPU/OCTA80 due to crystalline phase degradation, while TPU/EICO80 exhibited a 2 % increase, likely due to PCM restructuring; however, long-term trends suggest a potential decline. This simple, cost-effective and environmentally friendly fabrication process highlights the potential of upcycling TPU waste and offers a scalable approach for developing TPU/PCM membranes with promising applications in textile thermal management systems.
Open Access
Duplex treatments prepared by HiPIMS and sol-gel on biodegradable ZK60 magnesium alloy for biomedical applications
(Elsevier, 2025-09-01) Claver Alba, Adrián; Quintana, Iban; Fernández, Iván; Santiago, José A.; Díaz-Rodríguez, Pablo; Panizo-Laiz, Miguel; Zalakain Iriazabal, Iñaki; Urroz Unzueta, José Carlos; García Lorente, José Antonio; Ingeniería; Ingeniaritza; Institute for Advanced Materials and Mathematics - INAMAT2; Gobierno de Navarra / Nafarroako Gobernua
The utilization of magnesium-based biomaterials in biomedical applications has grown considerably in recent years due to their favourable biocompatibility, biodegradability, and mechanical properties that closely resemble those of bones. However, the use of Mg-based alloys in aggressive environments, such as human bodily fluids, is hindered by their susceptibility to rapid corrosion, which compromises their mechanical properties. This can lead to infections in the body due to uncontrolled corrosion. In this study, a novel approach was employed to enhance the corrosion resistance of biodegradable ZK60 magnesium alloy and achieve optimal surface properties that can potentially enhance its antibacterial performance, hardness, and toughness. This approach involved the application of duplex treatments consisting of TiN doped with Cu coatings deposited via high power impulse magnetron sputtering (HiPIMS) followed by a Sol-gel top layer. The study systematically investigated the surface properties (wettability, roughness, and morphology), hardness, toughness and adhesion of the coatings to the substrate. To assess the corrosion resistance, mass change and hydrogen evolution of the samples, they were immersed in Hanks Balanced Salts Solution. Electrochemical tests were conducted to estimate the corrosion behavior of the samples. The in-vitro corrosion tests results demonstrated that the duplex treatments enhanced the corrosion resistance of the uncoated magnesium alloy samples. The duplex treatments exhibited suitable properties, including high corrosion resistance, hardness, toughness and adequate values of wettability and porosity-roughness. Therefore, they can be considered a promising option for use in biodegradable magnesium implants.