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Papers by Fermin Garciandía

IMHE: Información de …, 2005

Información del artículo Máquina para la reparación y fabricación de moldes y matrices mediante t... more Información del artículo Máquina para la reparación y fabricación de moldes y matrices mediante técnica combinada de fresado y aporte láser.

Welding in The World, Apr 23, 2018

AlSi10Mg is the Al alloy most applied for selective laser melting (SLM) processing studies. The c... more AlSi10Mg is the Al alloy most applied for selective laser melting (SLM) processing studies. The characteristics and the density obtained for SLM-processed material is extremely influenced by the quality of the starting powder. Since the microstructure obtained after SLM is often metastable, the required heat treatment to obtain an Boptimized^microstructure can be significantly different than the one applied to conventionally cast or wrought Al alloys. In the present work, different thermal treatments have been applied to samples manufactured by SLM in order to investigate the effect on the microstructure and mechanical properties. The microstructural evaluation has been performed by SEM analysis and the mechanical properties have been determined by hardness measurements and tensile tests. Samples in the as-built condition, after stress relieving and under T6 heat treatment have been investigated to determine the best combination of properties.

Physics Procedia, 2014

Powder quality control is essential to obtain parts with suitable mechanical properties in Select... more Powder quality control is essential to obtain parts with suitable mechanical properties in Selective Laser Melting manufacturing technique. One of the most important advantages of such technique is that it allows an efficient use of the material, due to the possibility to recycle and reuse un-melted powder. Nevertheless, powder material properties may change due to repeated recycling, affecting this way the mechanical behavior of parts. In this paper the effect of powder reuse on its quality and on the mechanical properties of the resulting melted parts is studied via self-developed recycling methodology. The material considered for investigation was IN718, a nickel superalloy widely used in industry. After recycling powder up to 14 times, no significant changes were observed in powder and test parts properties. The results obtained in this work will help to validate powder recycling methodology for its use in current industrial Selective Laser Melting manufacturing.

Journal of Materials Processing Technology, 2021

Procedia CIRP, 2018

In today's business environment, the trend towards more product variety and customization is unbr... more In today's business environment, the trend towards more product variety and customization is unbroken. Due to this development, the need of agile and reconfigurable production systems emerged to cope with various products and product families. To design and optimize production systems as well as to choose the optimal product matches, product analysis methods are needed. Indeed, most of the known methods aim to analyze a product or one product family on the physical level. Different product families, however, may differ largely in terms of the number and nature of components. This fact impedes an efficient comparison and choice of appropriate product family combinations for the production system. A new methodology is proposed to analyze existing products in view of their functional and physical architecture. The aim is to cluster these products in new assembly oriented product families for the optimization of existing assembly lines and the creation of future reconfigurable assembly systems. Based on Datum Flow Chain, the physical structure of the products is analyzed. Functional subassemblies are identified, and a functional analysis is performed. Moreover, a hybrid functional and physical architecture graph (HyFPAG) is the output which depicts the similarity between product families by providing design support to both, production system planners and product designers. An illustrative example of a nail-clipper is used to explain the proposed methodology. An industrial case study on two product families of steering columns of thyssenkrupp Presta France is then carried out to give a first industrial evaluation of the proposed approach.

Revista de Metalurgia, 1998

Resumen En el presente documento se resumen los trabajos llevados a cabo en CETENASA (Dpto. Láser... more Resumen En el presente documento se resumen los trabajos llevados a cabo en CETENASA (Dpto. Láser) para la obtención de puntos de soldadura entre metales disimilares. El par metálico estudiado es M-35 y F-143, correspondientes a un acero rápido y un acero para muelles, respectivamente. Debido a las composiciones químicas de las aleaciones implicadas se comprende la dificultad para obtener soldaduras con estructuras aceptables, desde el punto de vista metalúrgico, dado el alto grado de fisuración que presentan estos materiales, especialmente el M-35. El presente trabajo es un avance de los primeros resultados encontrados dentro de una investigación más amplia, en la que se demuestran las posibilidades que presenta la soldadura con láser de C0 2. Palabras clave: Soldadura. Láser C0 2. Metales disimilares.

Welding International, 1999

The research carried out at CETENASA's laser department on the welding of dissimilar meta... more The research carried out at CETENASA's laser department on the welding of dissimilar metals is summarised here. The metallic pair studied is M-35 and F-143, a high speed steel and a spring steel, respectively. Due to the chemical composition of the alloys involved, the difficulty in obtaining welds with metallurgically acceptable structures is easily understood because of the high cracking

Physics Procedia, 2011

Superalloys are designed for service at temperatures above 540 ºC. Due to their properties at hig... more Superalloys are designed for service at temperatures above 540 ºC. Due to their properties at high temperatures, this family of materials is used in different aircraft engine components. Aeronautic components demand reliable joining technologies. The laser welding of three different superalloys have been performed and analysed. Due to reduced extension of the heat affected zone (HAZ), and high quality and ratio "depth/width" of welded seams, laser welding has been a first joining technology candidate to new designs of components for new engines. The laser welding trials results, properties obtained, and development of the homologation of laser welding process are described.

Revista de Metalurgia, 2004

Welding International, 2005

Over recent years, one of the most interesting developments in the automotive industry has been t... more Over recent years, one of the most interesting developments in the automotive industry has been the weight reduction of the automobile, thereby bringing about a reduction in fuel consumption. Among other requirements, automobile weight reduction and the maintenance of high performance levels necessitates the use of bodywork materials that have a high level of mechanical resistance. In this work, the

Computers & Mathematics with Applications, 2018

Part distortion is a critical issue during Additive Manufacturing (AM) of metallic parts since it... more Part distortion is a critical issue during Additive Manufacturing (AM) of metallic parts since it prevents this technology from being implemented at industrial level. To this regard, distortion prediction even from design stage has become crucial. Actually, numerical modelling methodologies play an important role here. Different modelling approaches have been developed but one of the most computationally efficient methodology to predict distortion is the so called inherent strain method. In this work an empirical methodology to determine inherent strains is presented. This is the input data in simplified Finite Element (FE) models in order to predict distortion and residual stress fields. These inherent strains are calculated considering layer lumping strategies that might be adopted in the numerical model as well. The procedure has been developed and validated using the wellknown twin-cantilever beam structure. Ti-6Al-4V beams have been manufactured by LPBF technology following different scanning strategies. Distortion after support removal has been measured in order to be compared against numerical results. The methodology has been applied at coupon level giving accurate results and providing a preliminary validation.

Metalindustria, 2014

En este trabajo se resumen las posibilidades actuales en fabricacion aditiva 3D de materiales met... more En este trabajo se resumen las posibilidades actuales en fabricacion aditiva 3D de materiales metalicos de piezas 100% funcionales. Se describen las tecnologias desarrolladas analizando sus ventajas y limitaciones y las tendencias actuales y futuras de desarrollo de estas tecnologias. Se muestran ejemplos reales de piezas y componentes fabricados mediante tecnologia de fusion selectiva mediante laser en los equipos de iK4 Lortek y se analizan las multiples aplicaciones en aeronautica, biomedicina, industria de la ciencia, maquinaria o moldes.

Journal of Manufacturing and Materials Processing

Fatigue properties of parts are of particular concern for safety-critical structures. It is well-... more Fatigue properties of parts are of particular concern for safety-critical structures. It is well-known that discontinuities in shape or non-uniformities in materials are frequently a potential nucleus of fatigue failure. This is especially crucial for the Ti6Al4V alloy, which presents high susceptibility to the notch effect. This study investigates how post-processing treatments affect the mechanical performance of Ti6Al4V samples manufactured by laser powder bed fusion technology. All the fatigue samples were subjected to a HIP cycle and post-processed by machining and using combinations of alternative mechanical and electrochemical surface treatments. The relationship between surface properties such as roughness, topography and residual stresses with fatigue performance was assessed. Compressive residual stresses were introduced in all surface-treated samples, and after tribofinishing, roughness was reduced to 0.31 ± 0.10 µm, which was found to be the most critical factor. Fractur...