1,154 research outputs found

    Open source arc analyzer: Multi-sensor monitoring of wire arc additive manufacturing

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    Low-cost high-resolution metal 3-D printing remains elusive for the scientific community. Low-cost gas metal arc wire (GMAW)-based 3-D printing enables wire arc additive manufacturing (WAAM) for near net shape applications, but has limited resolution due to the complexities of the arcing process. To begin to monitor and thus control these complexities, the initial designs of the open source GMAW 3-D printer have evolved to include current and voltage monitoring. Building on this prior work, in this study, the design, fabrication and use of the open source arc analyzer is described. The arc analyzer is a multi-sensor monitoring system for quantifying the processing during WAAM, which includes voltage, current, sound, light intensity, radio frequency, and temperature data outputs. The open source arc analyzer is tested here on aluminum WAAM by varying wire feed rate and measuring the resultant changes in the sensor data. Visual inspection and microstructural analysis of the printed samples looking for the presence of porosity are used as the physical indicators of quality. The value of the sensors was assessed and the most impactful sensors were found to be the light and radio frequency sensors, which showed arc extinction events and a characteristic ā€œgood weldā€ peak frequency

    Integrated voltageā€”current monitoring and control of gas metal arc weld magnetic ball-jointed open source 3-D printer

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    To provide process optimization of metal fabricating self-replicating rapid prototyper (RepRap) 3-D printers requires a low-cost sensor and data logger system to measure current (I) and voltage (V) of the gas metal arc welders (GMAW). This paper builds on previous open-source hardware development to provide a real-time measurement of welder I-V where the measuring circuit is connected to two analog inputs of the Arduino that is used to control the 3-D printer itself. Franklin firmware accessed through a web interface that is used to control the printer allows storing the measured values and downloading those stored readings to the userā€™s computer. To test this custom current and voltage monitoring device this study reports on its use on an upgraded all metal RepRap during the printing of aluminum alloy (ER1100, ER4043, ER4943, ER4047, and ER5356). The voltage and current data were analyzed on a per alloy basis and also layer-by-layer in order to evaluate the deviceā€™s efficacy as a monitoring device for 3-D printing and the results of the integrated design are discussed

    Open-Source TIG-Based Metal 3D-Printing

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    Metal 3-D printing has been relegated to high-cost proprietary high-resolution systems and low-resolution low-cost metal inert gas (MIG) systems. In order to provide a path to high-resolution, low-cost, metal 3-D printing, this manuscript proposes a new open source metal 3-D printer design based around a low-cost tungsten inert gas (TIG) welder coupled to a commercial open source self replicating rapid prototyper. Optimal printing parameters for the machine are acquired using a novel computational intelligence software. TIG has many advantages over MIG, such as having a low heat input, clean beads, and the potential for both high-resolution prints as well as insitu alloying of complex geometries. The design can be adapted to most RepRap-class systems and has a basic yet powerful free and open source software (FOSS) package for the characterization of the 3-D printer. This system can be used for fabricating custom metal scientific components and tools, near net-shape structural metal component rapid prototyping, adapting and depositing on existing metal structures, and is deployable for in-field prototyping for appropriate technology applications

    LOW-COST OPEN-SOURCE GMAW-BASED METAL 3-D PRINTING: MONITORING, SLICER, OPTIMIZATION, AND APPLICATIONS

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    Low-cost and open-source gas metal arc welding (GMAW)-based 3-D printing has been demonstrated yet the electrical design and software was not developed enough to enable wide-spread adoption. This thesis provides three novel technical improvements based on the application of mechatronic and software theory that when combined demonstrate the ability for distributed digital manufacturing at the small and medium enterprise scale of steel and aluminum parts. First, low cost metal inert gas welders contain no power monitoring needed to tune GMAW 3-D printers. To obtain this data about power and energy usage during the printing, an integrated monitoring system was developed to measure current (I) and voltage (V) in real-time. The new design of this monitoring system integrates an open source microcontroller and free and open source software on the open-source metal 3-D printer to record the data. Second, the primary obstacle to the diffusion of this technology was that existing slicing software, which determines the toolpath of the printhead was optimized for polymer 3-D printing and inappropriate for printed parts made from metal due to their mechanical strength. Previous prints were accomplished by manually designing the toolpath, which was not practical for real use by an extended userbase. To overcome the problem, the free and open-source slicing software, CuraEngine, was forked to MOSTMetalCura, which supports the needs of GMAW-based metal 3-D printing. The optimized setting for wire feed rate is calculated by the new slicer based on printing speed, bead width, layer height, and material diameter. Previous studies have shown that GMAW-based metal 3-D printing is capable of fabricating parts with good layer adhesion and porosity. However, this preliminary work lacked demonstrations of real-world applications. Finally, in this work, the practical applications of open-source GMAW-based metal 3-D printing are well demonstrated for both developing world and developed world applications including: 1) fixing an existing part by adding on a 3-D metal feature, 2) creating a product using the substrate as part of the component, 3) 3-D printing useful objects in high resolution, 4) near net shape objects and 5) making an integrated product using a combination of steel and polymer 3-D printing. The results prove that low-cost and open-source GMAW-based metal 3-D printing is ready for distributed manufacturing by SMEs and adequate for a wide range of applications

    Material Analysis of 3D Welded 5356 Aluminum Alloy

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    Metal 3D printing has been reserved for aerospace and high-end automotive industries because of its cost. A gas metal arc welder (GMAW) on a rugged 3D printer frame could make metal additive manufacturing an option for more industries and consumers. 3D welded aluminum has not been examined in depth as an option for additive manufacturing (AM). Extensive tests are necessary to determine the correct settings to use a metal inert gas (MIG) welder for AM. Porosity within the welded material must be evaluated to better understand the additive process. The material properties of 3D welded aluminum will be tested and compared to existing additive and traditional manufacturing methods. If strong enough this could reduce the cost of aerospace expeditions making tools like CubeSats more accessible to lower budget entities. Additionally, metal additive manufacturing could become more available and cost effective to use in any industry that requires manufacturing

    Design for Low-Cost Gas Metal Arc Weld-Based Aluminum 3-D Printing

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    Additive manufacturing, commonly known as 3-D printing, has the potential to change the state of manufacturing across the globe. Parts are made, or printed, layer by layer using only the materials required to form the part, resulting in much less waste than traditional manufacturing methods. Additive manufacturing has been implemented in a wide variety of industries including aerospace, medical, consumer products, and fashion, using metals, ceramics, polymers, composites, and even organic tissues. However, traditional 3-D printing technologies, particularly those used to print metals, can be prohibitively expensive for small enterprises and the average consumer. A low-cost open-source metal 3-D printer has been developed based upon gas metal arc weld (GMAW) technology. Using this technology, substrate release mechanisms have been developed, allowing the user to remove a printed metal part from a metal substrate by hand. The mechanical and microstructural properties of commercially available weld alloys were characterized and used to guide alloy development in 4000 series aluminum-silicon alloys. Wedge casting experiments were performed to screen magnesium, strontium, and titanium boride alloying additions in hypoeutectic aluminum-silicon alloys for their properties and the ease with which they could be printed. Finally, the top performing alloys, which were approximately 11.6% Si modified with strontium and titanium boride were cast, extruded, and drawn into wire. These wires were printed and the mechanical and microstructural properties were compared with those of commercially available alloys. This work resulted in an easier-to-print aluminum-silicon-strontium alloy that exhibited lower porosity, equivalent yield and tensile strengths, yet nearly twice the ductility compared to commercial alloys

    Realization of the true 3D printing using multi directional wire and arc additive manufacturing

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    Robotic wire and arc based additive manufacturing has been used in fabricating of metallic parts owing to its advantages of lower capital investment, higher deposition rates, and better material properties. Although many achievements have been made, the build direction of Wire Arc Additive Manufacturing (WAAM) is still limited in the vertical up direction, resulting in extra supporting structure usage while fabricating metallic parts with overhanging features. Thus, the current WAAM technology should be also called 2.5D printing rather than 3D printing. In order to simplify the deposition set up and increase the flexibility of the WAAM process, it is necessary to find an alternative approach for the deposition of ā€˜overhangsā€™ in a true 3D space. This dissertation attempts to realize true 3D printing by developing a novel multi directional WAAM system using robotic Gas Metal Arc Welding (GMAW) to additively manufacture metal components in multiple directions. Several key steps including process development, welding defect investigation and avoidance, and robot path generation are presented in this study

    Near Infrared Thermal Imaging for Process Monitoring in Additive Manufacturing

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    This work presents the design and development of a near infrared thermal imaging system specifically designed for process monitoring of additive manufacturing. The overall aims of the work were to use in situ thermal imaging to develop methods for monitoring process parameters of additive manufacturing processes. The main motivations are the recent growth in use of additive manufacturing and the underutilisation of near infrared camera technology in thermal imaging. The combination of these two technologies presents opportunities for unique process monitoring methods which are demonstrated here. A thermal imaging system was designed for monitoring the electron beam melting process of an Arcam S12. With this system a new method of dynamic emissivity correction based on tracking the melted material is shown. This allows for the automatic application of emissivity values to previously melted areas of a layer image. This reduces the potential temperature error in the thermal image caused by incorrect emissivity values or the assumption of a single value for a whole image. Methods for determining materials properties such as porosity and tensile strength from the in situ thermal imaging are also shown. This kind of analysis from in situ images is the groundwork for allowing part properties to be tuned at build time and could remove the need for post build testing that would determine if it is suitable for use. The system was also used to image electron beam welding and gas tungsten arc welding. With the electron beam welding of dissimilar metals, the thermal images were able to show the preheating effect that the melt pool had on the materials, the suspected reason for the processā€™s success. For the gas tungsten arc welding process analysis methods that would predict weld quality were developed, with the aim of later integrating these into the robotic welding process. Methods for detecting the freezing point of the weld bead and tracking slag spots were developed, both of which could be used as indicators of weld quality or defects. A machine learning algorithm was also applied to images of pipe welding on this process. The aim of this was to develop an image segmentation algorithm that could be used to measure parts of the weld in process and inform other analysis, like those above
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