We report the electrochemical potential of conductive filaments produced with recycled polylactic acid (rPLA) alongside a mixture of graphite (Gpt) and/or carbon black (CB) and castor oil to create an electrode ready-to-use. Additively-manufactured electrodes (AMEs) were compared with commercial-conductive filament composed of PLA and CB. The Gpt-CB-rPLA and CB-rPLA sensors showed lower charge-transfer resistance (Rct) and a greater heterogenous rate constant, k0, (Rct= 1040 ± 50 Ω and 1810 ± 30 Ω and k0= 6.91 (± 0.58) × 103 and 5.31 (± 0.40) × 103 cm s-1, respectively) compared to the sensor from the commercial filament (Rct = 9620 ± 280 Ω and k0 = 3.62 (± 0.38) ×10-3 cm s-1). The electrochemical response of [Fe(CN6)]3-/4- displayed a peak-to-peak separation of 180 ± 8 mV (Gpt-CB-rPLA) and 240 ± 6 mV (CB-rPLA) compared to commercial AME (740 ±10 mV), without any surface treatment. The filaments were used to create a 2,4,6-trinitrotoluene (TNT) detection platform with linear range of 5-20 and 5-100 µmol L-1 for Gpt-CB-rPLA and CB-rPLA, respectively. The collector-detector device was applied for the analysis of a blast simulation. Finally, it is worth noting that the results obtained are without electrode treatment/activation, indicating that the rough surface of the additively manufactured electrode is an additional feature of the device for collecting explosive residues, simply by rubbing the additively manufactured platform on different surfaces in crime scenarios. rPLA (rPLA Gpt (Gpt andor or CB (CB readytouse. readytouse ready use. use ready-to-use Additivelymanufactured Additively AMEs (AMEs commercialconductive GptCBrPLA CBrPLA chargetransfer charge transfer Rct constant k Rct= 104 5 181 3 691 91 6.9 ( 0.58 058 0 58 10 531 31 5.3 0.40 040 40 s1, s1 s 1, 1 s-1 respectively 962 28 362 62 3.6 0.38 038 38 ×103 ×10 ×10- s1. . s-1) FeCN63/4 FeCN634 FeCN Fe CN6 /4 4 CN [Fe(CN6)]3-/4 peaktopeak peak 18 (Gpt-CB-rPLA 24 (CB-rPLA 740 (74 ±1 mV, , mV) treatment 2,4,6trinitrotoluene 246trinitrotoluene trinitrotoluene 2,4,6 2 TNT (TNT 520 20 5-2 5100 100 5-10 L1 L L- CBrPLA, rPLA, collectordetector collector detector simulation Finally treatmentactivation activation treatment/activation residues scenarios 69 9 6. 0.5 05 53 5. 0.4 04 s- 96 36 3. 0.3 03 ×1 FeCN63 FeCN63/ / [Fe(CN6)]3-/ 74 (7 6trinitrotoluene 246 2,4, 52 5- 510 5-1 0. FeCN6 [Fe(CN6)]3- 7 2,4 51 [Fe(CN6)]3 2, [Fe(CN6)] [Fe(CN6) [Fe(CN6 [Fe(CN

This paper presents a methodological approach to conducting a literature review on additive manufacturing (AM), which is a groundbreaking manufacturing technique that involves the successive layering of materials to create components. The use of AM not only reduces manufacturing waste but also saves time and simplifies assembly processes. The current research focused on exploring the advances of AM in fabricating self-lubricating components. By using specific keywords, relevant data sources were extracted from databases. The literature review highlights the extensive exploration of AM in tribological research, demonstrating its successful application in creating self-lubricating components that have yielded positive results.

Hierdie artikel bied 'n metodologiese benadering tot die uitvoer van 'n literatuuroorsig oor laag-op-laag vervaardiging, 'n baanbreker-vervaardigingstegniek waarin materiale in opeenvolgende lae neergelê word om komponente te vervaardig. Die gebruik van laag-op-laag vervaardiging verminder nie alleen vervaardigingsafval nie, maar spaar ook tyd en vereenvoudig samestellingsprosesse. Hierdie navorsing het gefokus op die ondersoek van vooruitgang in laag-op-laag vervaardiging in die maak van selfsmerende komponente. Deur spesifieke sleutelwoorde te gebruik, is relevante databronne verkry vanuit databasisse. Hierdie literatuuroorsig beklemtoon die uitgebreide verkenning van laag-op-laag vervaardiging in tribologiese navorsing, en demonstreer die suksesvolle toepassing daarvan in die maak van selfsmerende komponente wat positiewe resultate opgelewer het.

Resumen Introducción: La popularidad de la cirugía asistida con impresión 3D ha crecido en los últimos 10 años. El poco empleo en nuestro medio no permite aprovechar para el paciente todas las aplicaciones y los beneficios de esta herramienta. Materiales y Métodos: Estudio retrospectivo sobre enfermedad del miembro inferior en pacientes tratados en nuestra institución analizando cada etapa del proceso y su utilidad en la planificación, la ejecución quirúrgica y el desarrollo de implantes. Resultados: Se describen 12 casos en los que se utilizó la impresión 3D para tratar defectos acetabulares, resecciones tumorales óseas y secuelas en huesos largos. Conclusiones: Nuestra serie y la bibliografía revisada demuestran que la cirugía asistida con impresión 3D mejora la predictibilidad con lo planificado y reduce los tiempos quirúrgicos, el sangrado y la radiación intraoperatoria, a un costo accesible. Además, no se han comunicado complicaciones asociadas a esta tecnología.

Abstract Introduction: The popularity of 3D printing-assisted surgery has surged over the previous decade. The tool’s limited use in our context prevents us from taking advantage of all of its applications and benefits for the patient. Materials and Methods: A retrospective study on lower limb disease in patients treated at our institution, analyzing each stage of the procedure and its applicability in planning, surgical execution, and implant development. Results: We describe 12 cases in which 3D printing was used to treat acetabular defects, bone tumor resections, and long bone sequelae. Conclusions: Our series and the literature reviewed demonstrate that 3D printing-assisted surgery improves plan predictability while also reducing surgical times, bleeding, and intraoperative radiation at a reasonable cost. Furthermore, no complications from this technology have been reported.

Abstract Additive manufacturing has evolved from a rapid prototyping technology to a technology with the ability to produce highly complex parts with superior mechanical properties than those obtained conventionally. The processing of metallic powders by means of a laser makes it possible to process any type of alloy and even metal matrix composites. The present work analyzes the tensile and compressive response of 316L stainless steel processed by laser-based powder bed fusion. The resulting microstructure was evaluated by optical microscopy. Regarding the mechanical properties, the yield strength, ultimate tensile strength, percentage of elongation before breakage, compressive strength and microhardness were determined. The results show that the microstructure is constituted by stacked micro molten pools, within which cellular sub-grains are formed due to the high thermal gradient and solidification rate. The compressive strength (1511.88 ± 9.22 MPa) is higher than the tensile strength (634.80 ± 11.62 MPa). This difference is mainly associated with strain hardening and the presence of residual stresses. The initial microhardness was 206.24 ± 11.96 HV; after the compression test, the hardness increased by 23%.

Resumen La fabricación aditiva ha evolucionado desde una tecnología de prototipado rápido hasta una con la capacidad de producir piezas altamente complejas con propiedades mecánicas que superan las logradas de manera convencional. El procesamiento de polvos metálicos mediante tecnología láser permite el tratamiento de una amplia gama de aleaciones e incluso materiales compuestos. Este estudio analiza la respuesta a tracción y compresión del acero inoxidable 316L fusionado mediante fusión selectiva láser. La microestructura resultante fue analizada mediante microscopía óptica. En cuanto a las propiedades mecánicas, se determinaron la resistencia a la fluencia, la resistencia última a la tracción, el porcentaje de elongación antes de la fractura, la resistencia a la compresión y la microdureza. Los resultados muestran que la microestructura está compuesta por micropiletas fundidas apiladas, dentro de las cuales se generan subgranos celulares debido al alto gradiente térmico y la alta velocidad de solidificación. La resistencia a la compresión (1511.88 ± 9.22 MPa) es superior a la resistencia a tracción (634.80 ± 11.62 MPa). Esta diferencia está principalmente asociada con el endurecimiento por deformación y las tensiones residuales. La microdureza inicial fue de 206.24 ± 11.96 HV, y después de la prueba de compresión, la dureza aumentó en un 23 %.

Abstract The use of polylactic acid scaffolds has been gaining ground in bone regeneration due to its ability to biodegrade. However, its use in clinical practice is limited, among other aspects, by its low bioactivity. The objective of this work is to evaluate two schemes for the deposition of calcium phosphate coatings on polylactic acid scaffolds made by the Fused Deposition Modeling method. The scaffold surfaces were activated by alkaline treatment in a 0.1M aqueous NaOH solution for 24 h at room temperature. In the deposition of the coatings, a solution supersaturated in calcium ions was used. The two deposition schemes were differentiated by the pH value presented by the solution after the precipitation stage. Nanostructured calcium phosphate deposits of the brushite (scheme 1) and apatite (scheme 2) type were obtained. Deposition scheme 2 generated a greater covered area on the surface of the scaffolds, higher calcium and phosphorus contents and a Ca/P ratio of 1.71 in their agglomerates.

Resumen El uso de andamios de ácido poli láctico ha venido ganando espacio en la regeneración ósea debido a su capacidad de biodegradarse. No obstante, su empleo en la práctica clínica se encuentra limitado, entre otros aspectos, por su escasa bioactividad. El presente trabajo tuvo como objetivo evaluar dos esquemas de deposición de recubrimientos de fosfato de calcio sobre andamios de ácido poliláctico elaborados mediante el método de Modelado por Deposición Fundida. Las superficies de los andamios fueron activadas mediante un tratamiento alcalino en una disolución acuosa al 0,1M de NaOH durante 24 h a temperatura ambiente. En la deposición de los recubrimientos se utilizó una disolución sobresaturada en iones calcio. Los dos esquemas de deposición se diferenciaron por el valor del pH presentado por la disolución después de la etapa de precipitación. Se obtuvieron depósitos de fosfatos de calcio nanoestructurados del tipo brushita (esquema 1) y apatita (esquema 2). El esquema de deposición 2 generó en la superficie de los andamios mayor área recubierta, superiores contenidos de calcio y fósforo y una relación Ca/P de 1,71 en sus aglomerados.

Abstract Worldwide more than 7 billion tons of lignocellulosic biomass will be produced by 2025. In Colombia, these residues are mainly disposed of in rivers and open fields, and only 10% is reused and recycled. Non-centrifugal sugarcane bagasse (SCB) is a residue obtained after sugarcane juice extraction during the manufacturing process of panela and is mostly used as fuel for boilers at sugar mills. Wheat bran (WB) is the main waste from wheat flour production. Nonetheless, the chemical composition of these by-products makes them suitable for use as substrates for hemicellulolytic enzyme production from fungi. Here, a whole process for production in a solid-state fermentation system, recovery, and ultrafiltration process for concentration of xylanases by Penicillium sp. Pn004 is presented. The higher productivity (26.7 ± 1.59 U gds-1 day-1) was reached on the fifth day of fermentation with an enzyme activity of 130.0 ± 7.95 U gds-1. The batch ultrafiltration process allowed increasing the xylanase activity up to 19-fold in the retentate, from 66.47 U mL-1 to 1486.83 U mL-1, without reaching a steady state flux through the membrane. Finally, the enzymatic extract achieved a 43% release of sugar from kikuyu grass (Cenchrus clandestinus), showing its potential to be used as an additive for silage or for enzymatic saccharification of lignocellulosic materials for sugar production.

Abstract. One of the key features of mechanical seals is to achieve effective sealing between two mechanical parts to prevent displacement and coolant leakage in industrial applications. Currently most of these elements are produced using neoprene, compressed cardboard, tar paper, laminated graphite, so we sought to produce them using ABS and PLA materials. For the design we used CAD software with educational license intended for educators and researchers, then a finite element analysis is performed according to the specifications of the product. In this sense, the importance of FEM as an evaluation tool has been identified in the context of this trend of using innovative technologies for research. As part of the results, the data obtained allow the selection of both variables and physical properties of the connecting rod and can be used to develop projects and studies of this nature applicable in case studies related to mechanical, mechatronic, industrial and electronic engineering. Finally, the variables Factor of Safety (FS), Von Mises Stress (VM) and YZ Stress, are analyzed after simulation by FEM, providing a range of values for use in engineering applications with different techniques in which connecting rods are used, FS [ 0.55, 12.26], VM [1.63, 36.45], YZ [-1.36, 10.13]. As for the other results presented in this study, the correlation coefficient is used as a statistical part with graphs to evaluate the simulation, the dependence of variables and parameters relevant to the case study, so a strong relationship was observed between the variables; plane stress, deformation, displacement and Von Mises stress, whose values range between 0.87 and 0.99, showing a strong relationship between these variables and, for the others, it should be considered to improve the relationship and increase the coefficient.

Resumen. - Una de las características clave de los sellos mecánicos es lograr una estanqueidad efectiva entre dos piezas mecánicas para evitar el desplazamiento y las fugas de refrigerante en aplicaciones industriales. Actualmente la mayoría de estos elementos se producen utilizando neopreno, cartón comprimido, papel alquitranado, grafito laminado, por lo que buscamos producirlos utilizando materiales ABS y PLA. Para el diseño se utilizó software CAD con licencia educativa destinada a educadores e investigadores, posteriormente se realiza un análisis de elementos finitos según las especificaciones del producto. En este sentido, se ha identificado la importancia del FEM como herramienta de evaluación en el contexto de esta tendencia de utilizar tecnologías innovadoras para la investigación. Como parte de los resultados, los datos obtenidos permiten seleccionar tanto las variables como las propiedades físicas de la biela y pueden ser utilizados para desarrollar proyectos y estudios de esta naturaleza aplicables en casos de estudio relacionados con la Ingeniería mecánica, mecatrónica, industrial y electrónica. Finalmente, las variables Factor de Seguridad (FS), Von Mises Stress (VM) y YZ Stress, se analizan después de la simulación mediante FEM, proporcionando un rango de valores para su uso en aplicaciones de ingeniería con diferentes técnicas en las que se utilizan bielas, FS [ 0,55, 12,26], VM [1,63, 36,45], YZ [-1,36, 10,13]. En cuanto a los demás resultados presentados en este estudio, el coeficiente de correlación se utiliza como parte estadística con gráficos para evaluar la simulación, la dependencia de variables y parámetros relevantes para el estudio de caso, por lo que se observó una fuerte relación entre las variables; esfuerzo plano, deformación, desplazamiento y el esfuerzo de Von Mises, cuyos valores oscilan entre 0,87 y 0,99, mostrando una fuerte relación entre estas variables y, para las demás, se debe considerar mejorar la relación y aumentar el coeficiente.

Additive manufacturing (AM) technology depends on the implemented selective laser melting (SLM) process. A good comprehension of its parameters is required to perform an efficient SLM process. Therefore, this study develops a computational fluid dynamic (CFD) model to simulate the SLM process based on a novel approach (particle by particle) and analyze its operating parameters. The model is based on the classical physics laws to formulate the governing equations and solve them in the ANSYS FLUENT software WORKBENCH R19.1. Melting of stainless steel 316L powder particles was considered a case study where laser power, scanning speed, and spot diameter were considered steady parameters. A User Define Function (UDF) is written in C-language to define the heat source and its parameters, and then it is run over the cell face center in every time step. A parametric study was conducted for three of the SLM main parameters; laser power, spot diameter, and scanning speed. The model was verified through the validation process, which confirmed the model's accuracy and reliability. The model outcomes revealed a proportional relationship between the laser power and each melting temperature and liquid mass fraction for a fixed spot diameter and scanning speed. Moreover, a higher energy density is achieved for a smaller laser spot diameter, which yields a higher liquid fraction and melt temperature. AM (AM (SLM Therefore CFD (CFD particle R191 R R19 1 R19.1 L speed UDF (UDF Clanguage C language step models s reliability Moreover R1 R19.

Abstract This research characterized the morphological and chemical characteristics, as well as the biocidal effectiveness of polylactic acid (PLA) plate surfaces, created through additive manufacturing, both with and without an additional sealing coating of a polymer infused with silver nitrate crystals. In acknowledgement of the well-accepted principle of silver-based materials as antibacterial agents, this study delves deeper into the underlying mechanism responsible for the bactericidal effect of the sealant, offering a thorough characterization of the system and its behavior. To assess the bactericidal effect of the system, a suite of techniques including visual examination, optical microscopy (OM), digital image processing (DIP), scanning electron microscopy (SEM), semi-quantitative chemical analyses using energy dispersive spectroscopy (EDS), average roughness (Ra) computations, and in vitro tests were employed. The goal was to assess the impact of the presence or absence of the sealant on the proliferation of Escherichia coli American Type Culture Collection (ATCC) 11229 and Staphylococcus aureus ATCC 25923 bacteria. Results showed that the sealant had a significant antimicrobial effect, reducing the number of bacteria on the coated surfaces by at least 64 times within 30 minutes, in comparison with uncoated surfaces. This study also revealed the presence of micropores in the cross-section of the sealant layer. The microporous structure likely served as a conduit for silver ions from the encapsulated silver nitrate to exert their bactericidal effect on bacterial colonies. Whilst reinforcing the well-known bactericidal efficacy of silver, this investigation underscores the potential applicability of the proposed sealant in various fields requiring antimicrobial protection. characteristics PLA (PLA manufacturing crystals wellaccepted accepted silverbased based agents behavior examination OM, OM , (OM) DIP, DIP (DIP) SEM, SEM (SEM) semiquantitative semi quantitative EDS, EDS (EDS) Ra (Ra computations employed (ATCC 1122 2592 6 3 minutes crosssection cross section layer colonies wellknown known protection (OM (DIP (SEM (EDS 112 259 11 25 1 2

Abstract The wire arc additive manufacturing process or WAAM (Wire Additive Arc Welding) is recognized as a process able of making pieces of high geometric complexity, with mechanical properties comparable to those of the cast material. However, there are significant challenges associated with WAAM, such as undesirable microstructures and mechanical properties, high residual stresses and geometric distortion. This study aims to contribute to the selection of deposition parameters for VP50IM steel using WAAM via pulsed TIG (Tungsten Inert Gas) and characterization of the generated stacking, using the Central Composite Complete methodology, CCC. In this study, the peak (Cp) and base (Cb) current, wire feed speed during peak (Vap), base (Vab) and welding speed (Vs) were varied. The ideal parameter presented was Cp=200A, Cb=100A, Vap=2.9cm/min, Vab=1.2cm/min and Vs=20cm/min. Tensile tests showed up to 15% greater resistance in the samples in the longitudinal section in the welding direction compared to the transverse direction. Hardness tests demonstrated up to 9% less hardness at the center of the stack compared to the top and bottom. The fracture analysis of the specimens showed ductile fracture. Wire Welding complexity material However distortion VPIM VP IM Tungsten Gas stacking methodology CCC Cp (Cp Cb (Cb current Vap, Vap , (Vap) Vab (Vab Vs (Vs varied Cp200A CpA 200A A Cp=200A Cb100A CbA 100A Cb=100A Vap29cmmin Vapcmmin 2 9cm min cm Vap=2.9cm/min Vab12cmmin Vabcmmin 1 2cm Vs20cmmin Vscmmin 20cm Vs=20cm/min 15 9 bottom (Vap cmmin

Resumo O processo de manufatura aditiva a arco arame ou WAAM (Wire Additive Arc Welding) é reconhecido como um processo capaz de confeccionar peças de elevada complexidade geométrica, com propriedades mecânicas comparáveis às do material fundido. Entretanto, existem desafios significativos associados ao WAAM, como microestruturas e propriedades mecânicas indesejáveis, elevadas tensões residuais e distorção geométrica. Este estudo visa contribuir com a seleção de parâmetros de deposição do aço VP50IM utilizando WAAM via TIG (Tungsten Inert Gas) pulsado e caracterização do empilhamento gerado, utilizando a metodologia Central Composto Completo, CCC. Neste estudo variou-se a corrente de pico (Cp) e de base (Cb), velocidade de alimentação de arame durante pico (Vap), base (Vab) e velocidade de soldagem (Vs). O parâmetro ideal apresentado foi Cp=200A, Cb=100A, Vap=2,9cm/min, Vab=1,2cm/min e Vs=20cm/min. Ensaios de tração mostraram uma resistência até 15% maior nas amostras na seção longitudinal ao sentido de soldagem em comparação ao sentido transversal. Ensaios de dureza demonstraram uma dureza até 9% menor no centro do empilhamento em comparação ao topo e base. A análise de fratura dos corpos de prova evidenciou fratura dúctil. Wire Welding geométrica fundido Entretanto indesejáveis VPIM VP IM Tungsten Gas gerado Completo CCC variouse variou se Cp (Cp Cb, Cb , (Cb) Vap, Vap (Vap) Vab (Vab Vs. Vs . (Vs) Cp200A CpA 200A Cp=200A Cb100A CbA 100A Cb=100A Vap29cmmin Vapcmmin 2 9cm min cm Vap=2,9cm/min Vab12cmmin Vabcmmin 1 2cm Vs20cmmin Vscmmin 20cm Vs=20cm/min 15 transversal 9 dúctil (Cb (Vap (Vs cmmin

The integration of Inconel 718 (IN718) and Cold Metal Transfer (CMT) based wire + arc additive manufacturing (WAAM) for wall fabrication with a near-net shape and low buy-to-fly ratio presents a novel and promising approach with potential applications in various industrial sectors, including aerospace and automotive industries. This research aims to investigate the microstructure and mechanical anisotropy of thin-walled IN718 components that were produced using CMT based WAAM, and to compare the properties of as-deposited and heat-treated samples that underwent aerospace (AMS5663) procedures. To characterize the microstructure of the specimens, we employed optical microscopy and scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) and an element probe microanalyzer (EPMA). Tensile and hardness tests were conducted to evaluate the mechanical properties of the specimens. Our results revealed that the as-deposited samples exhibited a dendritic microstructure with a high degree of segregation, leading to lower mechanical strength than that of the heat-treated specimens. Precipitated heat treatment promoted the precipitation of strengthening phases, such as gamma prime and carbides, improving the mechanical properties. In contrast, the precipitated heat-treated specimens exhibited a more refined microstructure with equiaxed grains and a significantly enhanced mechanical strength. This study provides critical insights into optimizing the material for different applications, leading to the development of more efficient and effective parts. 71 IN (IN718 (CMT WAAM (WAAM nearnet near net buytofly buy fly sectors industries thinwalled thin walled IN71 asdeposited deposited heattreated treated AMS5663 AMS (AMS5663 procedures SEM (SEM EDS (EDS EPMA. EPMA . (EPMA) segregation phases carbides contrast parts 7 (IN71 IN7 AMS566 (AMS566 (EPMA (IN7 AMS56 (AMS56 (IN AMS5 (AMS5 (AMS

ABSTRACT Introduction: 3-dimensional printing has enabled the development of unique and affordable additive manufacturing, including the prototyping and production of surgical forceps. Objective: demonstrate the development, 3D printing and mechanical-functional validation of a laparoscopic grasping forceps. Methods: the clamp was designed using a computer program and printed in 3 dimensions with polylactic acid (PLA) filament and added 5 screws for better leverage. Size and weight measurements were carried out, as well as mechanicalfunctional grip and rotation tests in the laboratory with a validated simulator. Results: Called “Easylap”, the clamp weighed 48 grams, measured 43cm and was printed in 8 pieces, taking an average of 12 hours to produce. It allowed the simulation of the functional characteristics of laparoscopic pressure forceps, in addition to the rotation and rack locking mechanism. However, its strength is reduced due to the material used. Conclusion: It is possible to develop plastic laparoscopic grasping forceps through 3-dimensional printing. Introduction 3dimensional dimensional manufacturing Objective D mechanical Methods PLA (PLA leverage out simulator Results Easylap, Easylap , “Easylap” 4 grams cm pieces 1 produce mechanism However used Conclusion “Easylap

RESUMO Introdução: a impressão em 3 dimensões permitiu o desenvolvimento de manufaturas aditivas únicas e acessíveis, inclusive na prototipagem e produção de pinças cirúrgicas. Objetivo: Demonstrar o desenvolvimento, a impressão em 3D e a validação mecânico-funcional de pinça laparoscópica do tipo apreensão. Métodos: a pinça foi desenhada em programa de computador e impressa em 3 dimensões com filamento de ácido poliláctico (PLA) e acrescida de 5 parafusos para melhor efeito de alavanca. Foram realizadas aferições de tamanho e peso, bem como testes mecânicos-funcionais de preensão e rotação em laboratório com simulador validado. Resultados: denominada “Easylap”, a pinça pesou 48 gramas, mediu 43 cm e foi impressa em 8 peças, levando em média 12 horas para sua produção. Ela permitiu a simulação das características funcionais de pinça laparoscópicas de apreensão, além de mecanismo de rotação e travamento por cremalheira. Porém sua força é reduzida devido ao material utilizado. Conclusão: é possível desenvolver pinça laparoscópica plástica de apreensão através de impressão em 3 dimensões. Introdução acessíveis cirúrgicas Objetivo D mecânicofuncional mecânico funcional Métodos PLA (PLA alavanca peso mecânicosfuncionais mecânicos validado Resultados Easylap, Easylap , “Easylap” 4 gramas peças 1 cremalheira utilizado Conclusão “Easylap

This study explores the behavior of aluminum powder in laser powder bed fusion (LPBF) for additive manufacturing. Focusing on AlSi10Mg powders, the research investigates the effects of environmental conditions, such as temperature and humidity, on crucial properties like moisture content, fluidity, density, and agglomeration. Comprehensive tests, including particle size analysis and fluidity assessments, were conducted. Results showed increased flow time in the Carney funnel fluidity test after storage, but flow properties were maintained under high-temperature, low-humidity conditions. High humidity led to recurrent agglomerate formation. Moisture content analysis aligned with literature findings. Conclusively, these tests provide a reference for material acceptance and aid in supplier comparison for improved machine fluidity. While temperature and humidity impact aluminum oxide formation, humidity's greater relevance affects powder fluidity and quality. Other factors mentioned may cause permanent damage to the aluminum powder. LPBF (LPBF manufacturing AlSiMg AlSi Mg powders conditions density agglomeration assessments conducted storage hightemperature, hightemperature high temperature, high-temperature lowhumidity low formation findings Conclusively humiditys s quality

ABSTRACT Additive manufacturing opens new possibilities for new designs and manufacture of architected metamaterials and nanocomposites. Among the 3D printing technology, vat polymerization is highlighted due its higher resolution, smother surface and printing speed. In spite of the growing interest in the Additive Manufacturing technologies and the potential benefits of graphene reinforcement to improve the properties of parts produced by vat polymerization-based 3D Printing; there is a lack in understanding of the effects of adding graphene to photosensitive vat resin. Therefore, in this study the effect of adding graphene (0.3 and 0.5%) on the chemical, thermal and mechanical properties of parts fabricated by vat polymerization of a standard photosensitive acrylic resin was determined. Graphene addition resulted in a minimal modification of polymeric structure; however, it had a significant impact in the UV curing. The addition of graphene nanoplatelets hindered the photopolymerization of standard acrylic resin as consequence a higher amount of unpolymerized monomers are found after printing. Regarding the mechanical properties, graphene addition promoted a slight improvement in the Elastic Modulus while decreased tensile and flexural strength and it had no significative impact in toughness. An additional thermal curing step can be an alternative to improve polymerization and mechanical strength. These findings contribute to a deeper understanding of the effects of adding graphene to vat polymerization and its potential and limitations. nanocomposites D technology resolution speed polymerizationbased based Printing Therefore 0.3 03 0 3 (0. 0.5% 05 5 chemical determined structure however toughness limitations 0. (0 0.5 (

Abstract This paper investigates mold materials for polypropylene (PP) injection molding, including CuBe alloy (high thermal conductivity), AISI P20 mold steel (the conventional material for injection molds), and polyurethane resin (rapid tooling). Characterization of molded parts involved microstructural analysis, tensile tests, warping, and degree of crystallinity assessments. The results show that the higher thermal conductivity of the mold’s inserts reduced the injection molding cycle time and produced thicker skins, which resulted in smaller spherulite sizes in the core of the samples, reduced the crystallinity degree, and consequently reduced the maximum strain property. The thermal conductivity of the molds’ inserts was shown to be more significative than the skin thickness and mold temperature for the size of the spherulites when they are formed. In addition, CuBe alloys showed to be a strong competitor with additive manufacturing-produced molds with conformal cooling channels to reduce injection molding cycle time. PP (PP high conductivity, , conductivity) P P2 molds, molds) rapid tooling. tooling . tooling) analysis tests warping assessments s skins samples property formed addition manufacturingproduced manufacturing