Inventario de los molinos de la provincia de León en el Catastro de Ensenada y en los diccionarios de Miñado y Madoz

Se trata de un inventario de los molinos existentes en la provincia de León en el catastro de Ensenada y en los diccionarios de Sebastián Miñado y Pascual Madoz, comparando y tabulando los resultados obtenidos.Departamento de Prehistoria, Arqueología, Antropología Social y Ciencias y Técnicas HistoriográficasDoctorado en Patrimonio Cultural y Natural. Historia. Arte y Territori

Evaluation of mechanical properties of FDM components reinforced with fibre

[EN] This research analyses the influence of different parameters of the Fused Deposition Modelling process with continuous carbon fibre reinforcement upon tensile strength of manufactured parts. For that, the appropriate behaviour of specimens designed according to ISO 527 standard was verified, in a preliminary test. Hereafter, a full factorial Design of Experiment was proposed with five parameters and two levels. After manufacturing and testing the specimens, a regression including all possible interactions of the parameters was performed with their tensile results. This model was optimized, considering the terms with the highest statistical significance (p-value less than 0.05), so that a simplified model of 14 terms with an r-squared of 97.5% was obtained. Thanks to this research the tensile response of a printed part as a function of the chosen manufacturing parameters can be predicted in advance.S

Influence of Post-Processing on the Properties of Multi-Material Parts Obtained by Material Projection AM

[EN] The great geometric complexity that additive manufacturing allows in parts, together with the possibility of combining several materials in the same part, establishes a new design and manufacturing paradigm. Despite the interest of many leading sectors, the lack of standardization still makes it necessary to carry out characterization work to enjoy these advantages in functional parts. In many of these techniques, the process does not end with the end of the machine cycle, but different post-processing must be carried out to consider the part finished. It has been found that the type of post process applied can have a similar effect on part quality as other further studied process parameters. In this work, the material projection technique was used to manufacture multi-material parts combining resins with different mechanical properties. The influence of different post-processing on the tensile behavior of these parts was analyzed. The results show the detrimental effect of ultrasonic treatment with isopropyl alcohol in the case of the more flexible resin mixtures, being advisable to use ultrasonic with mineral oil or furnace treatment. For more rigid mixtures, the furnace is the best option, although the other post-processing techniques do not significantly deteriorate their performance.S

A comparison between discrete and continuous scanning with conoscopic holography

Low density digitizing is a suitable approach for verification distances between pairs of machined flat surfaces. When defining a digitizing procedure of this type of features, two approaches could be applied: discrete or continuous scanning. Discrete Scanning (D) is performed with a static sensor, but the information for each single measurement comes from a constrained area. On the other hand, since Continuous Scanning (C) is carried out with a moving sensor, the information for each single measurement comes from a swept area. In this work, a comparison between these two approaches, when digitizing with a Conoscopic Holography sensor, is performed. The main objective is to establish their influence upon surface reconstruction quality and, thereafter, upon measurement reliability.This work is supported by the Spanish Ministry of Economy and Competitiveness and FEDER (DPI2012-30987), the Regional Ministry of Economy and Employment of the Principality of Asturias (Spain) (SV-PA-13-ECOEMP- 15) and the Government of the Principality of Asturias through the Programme “Severo Ochoa” 2014 of PhD grants for research and teaching (BP14-049).Análisis de diferencias de resultados en términos metrológicos de distancia 3D entre planos, utilizando diferentes estategias de digitalizado con un sensor de Holografía Conoscópica integrado en una máquina de medición por coordenadas

Influence of surface location within depth of field on measuring by a conoscopic holography sensor integrated in a machining centre

Estudio de la influencia de la posición en el campo de trabajo sobre los resultados de medición de un sensor de holografía conoscópica integrado en un centro de mecanizado.In this work, a Conoscopic Holography (CH) sensor integrated in a Machining Centre (MC) was used for analysing how the measurements taken are influenced by the location of the digitized surface within depth of field (DOF). With this aim, two different digitizing strategies were conducted on a stepped specimen with flat surfaces. In the first strategy each step of the specimen was located at different positions within DOF whereas the CH sensor was kept at a constant height along the scanning of all steps. In the second strategy the sensor height was adapted so that each step was scanned at the same distance within DOF. The comparison between both strategies was performed by calculating the discrepancies between measurements taken by the CH sensor and those obtained by a touch probe (TP) also installed in the MC. Finally, the study provides a series of recommendations for practical application of the sensor.This work is supported by the Spanish Ministry of Economy and Competitiveness and FEDER (DPI2012-30987), the Regional Ministry of Economy and Employment of the Principality of Asturias (Spain) (SV-PA-13-ECOEMP-15) and the Government of the Principality of Asturias through the Programme “Severo Ochoa” 2014 of PhD grants for research and teaching (BP14-049)

Influence of 17-4 PH stainless steel powder recycling on properties of SLM additive manufactured parts

[EN] Metal Additive Manufacturing (AM) processes are developing quickly. These processes have several attractive qualities, however, the quality of manufactured parts still remains a major issue that needs to be addressed if it is to become a prevalent technology in the industry. In some powder bed fusion techniques, such as Selective Laser Melting (SLM), there is a portion of initial powder that does not melt and it can be recycled to ensure the economic and environmental viability of the process. In previous research, we demonstrated the morphological, chemical and microstructural change suffered by 17-4 PH stainless steel powder after reusing it in a SLM manufacturing process. In this work, the properties of 17-4 PH stainless steel parts, printed from powder in different recycling states (virgin powder (P0) and 20 times reused powder (P20)), were evaluated, in order to establish good recycling procedures and optimise the SLM process performance. Analyses of the properties revealed a slight decrease in roughness and pore size with powder recycling. The external porosity of the samples is similar in both powder states; however, internal porosity decreases by increasing the number of reuse cycles. Regarding the microstructural analysis, a slight increase in the γ-phase is observed with the powder recycling, which leads to a slight increase in ductility and decrease in hardness of the samples. Therefore, it is concluded that the 17-4 PH powder recycling process in SLM manufacturing is adequate and recommended to ensure the economic and environmental viability of the process without adversely affecting the properties of the parts.S