Solid State Additive Manufacturing of Acrylonitrile Butadiene Styrene with Silica Augmentative: Application of Friction Stir Processing

Additive manufacturing is an emerging method to produce customized parts with functional materials without big investments. As one of the common additive manufacturing methods, fused deposition modeling (FDM) uses thermoplastic-based feedstock. It has been recently adapted to fabricate composite materials too. Acrylonitrile butadiene styrene (ABS) is the most widely used material as FDM feedstock. However, it is an electrically insulating polymer. Carbon Nanotubes (CNTs) on the other hand are highly conductive. They are attractive fillers because of their high aspect ratio, and excellent mechanical and physical properties. Therefore, a nanocomposite of these two materials can give an electrically conductive material that is potentially compatible with FDM printing. This work focuses on the investigation of the relationships between the FDM process parameters and the electrical conductivity of the printed ABS/CNT nanocomposites. Nanocomposite filaments with CNT contents up to 10wt% were produced using a twin-screw extruder followed by 3D printing using FDM method. The starting material was pellets from a masterbatch containing 15 wt% CNT. Compression-molded samples of ABS/CNT were also prepared as the bulk baselines. The effects of CNT content and nozzle size on the through-layer and in-layer electrical conductivity of the printed nanocomposites were analyzed. Overall, a higher percolation threshold was observed in the printed samples, compared to that of the compression-molded counterparts. This resulted in the conductivity of the printed samples that is at least one order of magnitude lower. Moreover, at CNT contents up to 5 wt%, the in-layer conductivity of the printed samples was almost two orders of magnitudes higher than that in the through-layer direction. In ABS/3 wt% CNT samples, the through-layer conductivity continuously decreased as the nozzle diameter was decreased from 0.8 mm to 0.35 mm. These variations in the electrical conductivity were explained in terms of the CNT alignment, caused by the extrusion process during the print, quality of interlayer bonding during deposition, and the voids created due to the discrete nature of the printing process.

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Microstructural and Mechanical Properties of a Solid-State Additive Manufactured Magnesium Alloy

Journal of Manufacturing Science and Engineering ◽

10.1115/1.4052968 ◽

2021 ◽

pp. 1-21

Author(s):

Thomas Robinson ◽

Malcolm Williams ◽

Harish Rao ◽

Ryan P. Kinser ◽

Paul Allison ◽

...

Keyword(s):

Mechanical Properties ◽

Additive Manufacturing ◽

Solid State ◽

Magnesium Alloy ◽

Magnesium Alloys ◽

Process Parameters ◽

Weight Ratio ◽

Structural Components ◽

Friction Stir ◽

Magnesium Alloy Az31b

Abstract In recent years, additive manufacturing (AM) has gained prominence in rapid prototyping and production of structural components with complex geometries. Magnesium alloys, whose strength-to-weight ratio is superior compared to steel and aluminum alloys, have shown potential in lightweighting applications. However, commercial beam-based AM technologies have limited success with magnesium alloys due to vaporization and hot cracking. Therefore, as an alternative approach, we propose the use of a near net-shape solid-state additive manufacturing process, Additive Friction Stir Deposition (AFSD), to fabricate magnesium alloys in bulk. In this study, a parametric investigation was performed to quantify the effect of process parameters on AFSD build quality including volumetric defects and surface quality in magnesium alloy AZ31B. In order to understand the effect of the AFSD process on structural integrity in the magnesium alloy AZ31B, in-depth microstructure and mechanical property characterization was conducted on a bulk AFSD build fabricated with a set of acceptable process parameters. Results of the microstructure analysis of the as-deposited AFSD build revealed bulk microstructure similar to wrought magnesium alloy AZ31 plate. Additionally, similar hardness measurements were found in AFSD build compared to control wrought specimens. While tensile test results of the as-deposited AFSD build exhibited a 20 percent drop in yield strength, nearly identical ultimate strength was observed compared to the wrought control. The experimental results of this study illustrate the potential of using the AFSD process to additively manufacture Mg alloys for load bearing structural components with achieving wrought-like microstructure and mechanical properties.

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Morphological and microstructural investigation of the non-planar interface formed in solid-state metal additive manufacturing by additive friction stir deposition

Additive Manufacturing ◽

10.1016/j.addma.2020.101293 ◽

2020 ◽

Vol 35 ◽

pp. 101293 ◽

Cited By ~ 2

Author(s):

Mackenzie E.J. Perry ◽

R. Joey Griffiths ◽

David Garcia ◽

Jennifer M. Sietins ◽

Yunhui Zhu ◽

...

Keyword(s):

Additive Manufacturing ◽

Solid State ◽

Planar Interface ◽

Microstructural Investigation ◽

Metal Additive Manufacturing ◽

Friction Stir ◽

Metal Additive

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Sustainable Additive Manufacturing: Mechanical Response of Acrylonitrile-Butadiene-Styrene over Multiple Recycling Processes

Sustainability ◽

10.3390/su12093568 ◽

2020 ◽

Vol 12 (9) ◽

pp. 3568 ◽

Cited By ~ 7

Author(s):

Nectarios Vidakis ◽

Markos Petousis ◽

Athena Maniadi ◽

Emmanuel Koudoumas ◽

Achilles Vairis ◽

...

Keyword(s):

Additive Manufacturing ◽

Mechanical Behavior ◽

Mechanical Response ◽

Positive Impact ◽

Research Work ◽

Acrylonitrile Butadiene Styrene ◽

Experimental Simulation ◽

Recycling Rate ◽

Fused Filament Fabrication ◽

Butadiene Styrene

Sustainability in additive manufacturing refers mainly to the recycling rate of polymers and composites used in fused filament fabrication (FFF), which nowadays are rapidly increasing in volume and value. Recycling of such materials is mostly a thermomechanical process that modifies their overall mechanical behavior. The present research work focuses on the acrylonitrile-butadiene-styrene (ABS) polymer, which is the second most popular material used in FFF-3D printing. In order to investigate the effect of the recycling courses on the mechanical response of the ABS polymer, an experimental simulation of the recycling process that isolates the thermomechanical treatment from other parameters (i.e., contamination, ageing, etc.) has been performed. To quantify the effect of repeated recycling processes on the mechanic response of the ABS polymer, a wide variety of mechanical tests were conducted on FFF-printed specimens. Regarding this, standard tensile, compression, flexion, impact and micro-hardness tests were performed per recycle repetition. The findings prove that the mechanical response of the recycled ABS polymer is generally improved over the recycling repetitions for a certain number of repetitions. An optimum overall mechanical behavior is found between the third and the fifth repetition, indicating a significant positive impact of the ABS polymer recycling, besides the environmental one.

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Additive Friction Stir-Enabled Solid-State Additive Manufacturing for the Repair of 7075 Aluminum Alloy

Applied Sciences ◽

10.3390/app9173486 ◽

2019 ◽

Vol 9 (17) ◽

pp. 3486 ◽

Cited By ~ 5

Author(s):

R. Joey Griffiths ◽

Dylan T. Petersen ◽

David Garcia ◽

Hang Z. Yu

Keyword(s):

Aluminum Alloy ◽

Additive Manufacturing ◽

Solid State ◽

Side Wall ◽

Fusion Welding ◽

7075 Aluminum Alloy ◽

Hole Filling ◽

Friction Stir ◽

Advantages And Disadvantages ◽

Through Hole

The repair of high strength, high performance 7075 aluminum alloy is essential for a broad range of aerospace and defense applications. However, it is challenging to implement it using traditional fusion welding-based approaches, owing to hot cracking and void formation during solidification. Here, the use of an emerging solid-state additive manufacturing technology, additive friction stir deposition, is explored for the repair of volume damages such as through -holes and grooves in 7075 aluminum alloy. Three repair experiments have been conducted: double through-hole filling, single through-hole filling, and long, wide-groove filling. In all experiments, additive friction stir deposition proves to be effective at filling the entire volume. Additionally, sufficient mixing between the deposited material and the side wall of the feature is always observed in the upper portions of the repair. Poor mixing and inadequate repair quality have been observed in deeper portions of the filling in some scenarios. Based on these observations, the advantages and disadvantages of using additive friction stir deposition for repairing volume damages are discussed. High quality and highly flexible repairs are expected with systematic optimization work on process control and repair strategy development in the future.

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Development of a gripper for garment handling designed for additive manufacturing

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406219857763 ◽

2019 ◽

pp. 095440621985776

Author(s):

Michal Jilich ◽

Mattia Frascio ◽

Massimiliano Avalle ◽

Matteo Zoppi

Keyword(s):

Mechanical Properties ◽

Additive Manufacturing ◽

Acrylonitrile Butadiene Styrene ◽

Cost Effective ◽

Lower Number ◽

Polybutylene Terephthalate ◽

Design Validation ◽

Polymeric Additive ◽

Lower Complexity ◽

Butadiene Styrene

The paper presents how a robotic gripper specific for grasping and handling of textiles and soft flexible layers can be miniaturized and improved by polymeric additive manufacturing-oriented re-design. Advantages of polymeric additive manufacturing are to allow a re-design of components with integrated functions, to be cost-effective equipment for small batches production and the availability of suitable materials for many applications. The drawback is that for design validation extended testing is still necessary because of lacks in standardization and that the mechanical properties are building parameters dependent. The outcomes are a lower complexity of the design overall and lower number of components. These are pursued taking advantage of the anisotropy of the additive manufacturing processed polymer and assigning appropriate shapes and linkages in the mechanisms. Set of common materials (polylactide, polyethylene terephthalate, acrylonitrile butadiene styrene) and technical (acrylonitrile styrene acrylate, polycarbonate/polybutylene terephthalate blend) are tested to obtain data for the modelling.

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