Matching Items (43)

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An Examination of the Impact of Support Design on 316 Stainless Steel Supports

Description

The removal of support material from metal 3D printed objects is a laborious necessity for the post-processing of powder bed fusion printing (PBF). Supports are typically mechanically removed by machining techniques. Sacrificial supports are necessary in PBF printing to relieve

The removal of support material from metal 3D printed objects is a laborious necessity for the post-processing of powder bed fusion printing (PBF). Supports are typically mechanically removed by machining techniques. Sacrificial supports are necessary in PBF printing to relieve thermal stresses and support overhanging parts often resulting in the inclusion of supports in regions of the part that are not easily accessed by mechanical removal methods. Recent innovations in PBF support removal include dissolvable metal supports through an electrochemical etching process. Dissolvable PBF supports have the potential to significantly reduce the costs and time associated with traditional support removal. However, the speed and effectiveness of this approach is inhibited by numerous factors such as support geometry and metal powder entrapment within supports. To fully realize this innovative approach, it is necessary to model and understand the design parameters necessary to optimize support structures applicable to an electrochemical etching process. The objective of this study was to evaluate the impact of block additive manufacturing support parameters on key process outcomes of the dissolution of 316 stainless steel support structures. The parameters investigated included hatch spacing and perforation, and the outcomes of interests included time required for completion, surface roughness, and effectiveness of the etching process. Electrical current was also evaluated as an indicator of process completion. Analysis of the electrical current throughout the etching process showed that the dissolution is diffusion limited to varying degrees, and is dependent on support structure parameters. Activation and passivation behavior was observed during current leveling, and appeared to be more pronounced in non-perforated samples with less dense hatch spacing. The correlation between electrical current and completion of the etching process was unclear, as the support structures became mechanically removable well before the current leveled. The etching process was shown to improve surface finish on unsupported surfaces, but support was shown to negatively impact surface finish. Tighter hatch spacing was shown to correlate to larger variation in surface finish, due to ridges left behind by the support structures. In future studies, it is recommended current be more closely correlated to process completion and more roughness data be collected to identify a trend between hatch spacing and surface roughness.

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2018-05

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Anisotropic Effects on the Mechanical Properties of Additively Manufactured Plastics

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This study analyzes mechanical properties of additively manufactured plastic materials produced in a conventional 3D printer. This topic has generally been studied in controlled scenarios, and this study aims to reflect the properties seen by consumers. Layered prints are inherently

This study analyzes mechanical properties of additively manufactured plastic materials produced in a conventional 3D printer. This topic has generally been studied in controlled scenarios, and this study aims to reflect the properties seen by consumers. Layered prints are inherently anisotropic due to the direction of the layers and associated weaknesses or stress concentrators. Thus, the ultimate strength and elastic modulus of plastic specimens produced using default settings are compared based on print orientation angle, and trends are observed. When a specimen is parallel to the build plate, it tends to have ultimate strength and elastic modulus near the published bulk values of 13.2MPa and 404-710MPa, but these values tend to decrease as the print angle increases.

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2018-05

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A Study of Metal Additive Manufacturing: DMLS Design for Optimizing Automobile Components

Description

Automobiles can advance greatly with the introduction of metal additive manufactured components. Additive tooling is slowly becoming additive manufacturing and someday the technology will be advanced enough that high volume can be supported. This research was conducted in order to

Automobiles can advance greatly with the introduction of metal additive manufactured components. Additive tooling is slowly becoming additive manufacturing and someday the technology will be advanced enough that high volume can be supported. This research was conducted in order to show the advantages metal additive manufacturing has in the automobile industry. One large advantage to metal additive manufacturing is mass reduction. Components can be designed for production with different geometries than other manufacturing methods. The change in geometry can significantly reduce the product volume and therefore mass. Overall, mass reduction in the automotive industry is beneficial. Mass reduction can increase performance and fuel economy of the car. Once metal additive manufacturing becomes capable of higher production, metal additive manufacturing will play a major role in automobile manufacturing. Research was conducted to design and produce an optimized AC compressor bracket. The bracket was designed to the specifications of the OEM component, and the mass was reduced by more than half.

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2017-05

Metallurgical Test Comparison of Aerospace Material using Additive Manufacturing Technologies vs. Wrought Technologies

Description

The aerospace industry has been conducting research on the additive manufacturing (AM) process since the 1980's, but companies have recently just begun to apply AM in hopes that this new technology will meet or exceed the requirements met by previous

The aerospace industry has been conducting research on the additive manufacturing (AM) process since the 1980's, but companies have recently just begun to apply AM in hopes that this new technology will meet or exceed the requirements met by previous manufacturing methods, as well as producing more cost effective, geometrically-complex products. This investigation evaluated the performance of 3D-printed aerospace test specimens made by Powder Bed Fusion Technologies, and compared them to forged specimens. A design of experiments varying build parameters was conducted in order to determine AM component porosity. Factors such as powder post-processing, directionality of the build, and fractology of the samples were evaluated through tensile strength testing and hardness testing of Inconel 718 wrought and EBM printed materials. Using electron microsopy, the responses to these factors were analyzed for stress fractures, grain boundaries, and other defects that occurred in the testing process. The comparison determined which metallurgical process provides the most effective material for aircraft usage.

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2017-05

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Effect of Powder Re-use on DMLS Product Integrity

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The purpose of this honors project is to analyze the difference between different powder separation techniques, and their suitability for my capstone project – ‘Effect of Powder Reuse on DMLS (Direct Metal Laser Sintering) Product Integrity’. Due to the nature

The purpose of this honors project is to analyze the difference between different powder separation techniques, and their suitability for my capstone project – ‘Effect of Powder Reuse on DMLS (Direct Metal Laser Sintering) Product Integrity’. Due to the nature of my capstone project, my group needs to characterize foreign contaminants in IN 718 (Ni-based superalloy) powder with a mean diameter around 40um. In order to clearly analyze the contaminants and recycle useful IN 718 powders, powder separation is favorable since the filtered samples will be much easier to characterize rather than inspect all the powders at once under microscope. By conducting literature review, I found that powder separation is commonly used in Geology, and Chemistry department. To screen which combination of techniques could be the best for my project, I have consulted several research specialists, obtained adequate knowledge about powder separation. Accordingly, I will summarize the pros and cons of each method with regard the specific project that I am working on, and further explore the impacts of each method under economical, societal, and environmental considerations. Several powder separation techniques will be discussed in details in the following sections, including water elutriation, settling column, magnetic separation and centrifugation. In addition to these methods, sieving, water tabling and panning will be briefly introduced. After detailed comparison, I found that water elutriation is the most efficient way to purity IN718 powder for reuse purpose, and recovery rate is as high as 70%, which could result in a significant reduction in the manufacturing cost for Honeywell since currently Honeywell only use virgin powders to build parts, and 90% of the leftover powders are discarded.

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2016-05

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Effect of Powder Reuse on DMLS (Direct Metal Laser Sintering) Product Integrity: Why Honeywell Believes the Future is Additive Manufacturing

Description

Honeywell is currently extending the reach of additive manufacturing (AM) in its product line and expects to produce as much as 40% of its inventory through AM in five years. Additive manufacturing itself is expected to grow into a $3.1

Honeywell is currently extending the reach of additive manufacturing (AM) in its product line and expects to produce as much as 40% of its inventory through AM in five years. Additive manufacturing itself is expected to grow into a $3.1 billion dollar industry in the next 5 to 10 years. Reusing IN 718 powder, a nickel-based super alloy metal powder, is an ideal option to reduce costs as well as reduce waste because it can be used with additive manufacturing, but the main obstacles are lack of procedure standardization and product quality assurances from this process. The goal of the capstone project, "Effect of Powder Reuse on DMLS (Direct Metal Laser Sintering) Product Integrity," is to create a powder characterization protocol in order to determine if the IN 718 powder can be reused and what effect the IN 718 reused powder has on the mechanical properties of the products Honeywell fabricates. To provide context and impact of this capstone project, this paper serves to identify the benefits of AM for Honeywell and the cost effectiveness of reusing the powder versus using virgin powder every time. It was found that Honeywell's investment in AM is due to the cost effectiveness of AM, versatility in product design, and to ensure Honeywell remains competitive in the future. In terms of reducing expenses, reusing powder enables costs to be approximately 45% less than using virgin powder. With these key pieces of information, the motivations for this capstone project are understood to a fuller and more profound degree.

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2016-05

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Effect of Powder Recycling on Direct-Metal-Laser-Sintered Aerospace Alloy

Description

This project sought to analyze the effects of recycling Inconel 718 powder for Direct Metal Laser Sintering (DMSL) for additive manufacturing by testing low cycle fatigue tensile samples ranging from virgin to ten times recycled. Fracture generally occurs at the

This project sought to analyze the effects of recycling Inconel 718 powder for Direct Metal Laser Sintering (DMSL) for additive manufacturing by testing low cycle fatigue tensile samples ranging from virgin to ten times recycled. Fracture generally occurs at the sample surface where persistent slip planes form and accumulate to cause a sudden fracture leading to signature markings for various phases of crack growth. Effects caused by contamination would be found in the first region of crack growth at the initiation site as the cause stress concentration. Tensile strength and fatigue life were compared to initiation site size found from fracture images obtained using scanning electron microscope imaging which found no significant deviations from the expected surface cracking and LCF region of slip plane buildups. Contamination was not found at any initiation site indicating that fracture life was not impacted by the amount of powder recycling. LCF life ranged from 60,000 to 250,000 which the majority experiencing fractures near 120,000 cyclic loadings. If defect effects were to be found than the low fatigue life sample would exhibit them however its fracture surface did not exhibit contamination but a slight increase in porosity found in the phase III cracking region. The In 718 powders were also analyzed to determine that the primary powder contaminates were brush fibers used to sweep away unused powders during processing however these were not seen in the final DMLS samples.

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2016-05

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Large-Scale Rapid Prototyping Utilizing Adaptive Slicing Techniques

Description

A method has been developed that employs both procedural and optimization algorithms to adaptively slice CAD models for large-scale additive manufacturing (AM) applications. AM, the process of joining material layer by layer to create parts based on 3D model data,

A method has been developed that employs both procedural and optimization algorithms to adaptively slice CAD models for large-scale additive manufacturing (AM) applications. AM, the process of joining material layer by layer to create parts based on 3D model data, has been shown to be an effective method for quickly producing parts of a high geometric complexity in small quantities. 3D printing, a popular and successful implementation of this method, is well-suited to creating small-scale parts that require a fine layer resolution. However, it starts to become impractical for large-scale objects due to build volume and print speed limitations. The proposed layered manufacturing technique builds up models from layers of much thicker sheets of material that can be cut on three-axis CNC machines and assembled manually. Adaptive slicing techniques were utilized to vary layer thickness based on surface complexity to minimize both the cost and error of the layered model. This was realized as a multi-objective optimization problem where the number of layers used represented the cost and the geometric difference between the sliced model and the CAD model defined the error. This problem was approached with two different methods, one of which was a procedural process of placing layers from a set of discrete thicknesses based on the Boolean Exclusive OR (XOR) area difference between adjacent layers. The other method implemented an optimization solver to calculate the precise thickness of each layer to minimize the overall volumetric XOR difference between the sliced and original models. Both methods produced results that help validate the efficiency and practicality of the proposed layered manufacturing technique over existing AM technologies for large-scale applications.

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Date Created
2016-05

Additive Manufacturing: The Effect of a Technology Shift on the Economy

Description

A look at current 3D printing capabilities, and exploring the potential for additive manufacturing to transform the economy in the future.

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2013-05

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Capillary Action in Additive Manufactured Channels for Thermal Management

Description

Due to the vast increase in processing power and energy usage in computing, a need for greater heat dissipation is prevalent. With numerous applications demanding cheaper and more efficient options for thermal management, new technology must be employed. Through the

Due to the vast increase in processing power and energy usage in computing, a need for greater heat dissipation is prevalent. With numerous applications demanding cheaper and more efficient options for thermal management, new technology must be employed. Through the use of additive manufacturing, designs and structures can be created that were not physically possible before without extensive costs. The goal is to design a system that utilizes capillary action, which is the ability for liquids to flow through narrow spaces unassisted. The level of detail required may be achieved with direct metal laser sintering (DMLS) and stereolithography (SLA) 3D printing.

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2021-05