scholarly journals XPS and SEM characterization for powder recycling within 3d printing process

2021 ◽  
Author(s):  
Nima E. Gorji ◽  
Robert O'Connor ◽  
Dermot Brabazon

In recent years, recycling the powder leftover within the additive manufacturing process has been attractive for both research, development and industry production. Powder recycling can significantly enhance the sustainability of the manufacturing process, reduce the cost and avoid producing metallic waste as a potential environmental hazard. The first step in reusing the recycled powders in the 3D printing process is to characterize the microstructure and surface quality of the powder for oxidation and impurity analysis. Here, scanning electron microscopy (SEM) and x-ray photoelectron spectroscopy (XPS) have been used for the morphology and surface composition analysis of the 316L powders within the Aconity 3D printer. A new powder collection strategy has been introduced to collect powders from different locations in the powder bed: from the top most and surface of the parts and powder bed after the print terminated, from between the printed parts at different heights. The XPS measurements revealed that oxidation is a common in all the powders compared to virgin powder and more oxidation was detected from the powders collected on the very top of the leftover powder and from surface of the bed. The size of the particles does not change much but larger particles remained at the topmost surface. This finding would help in designing a protocol for collecting the recycled powder from the powder bed and it is suggested to follow a a procedure of collecting powders from the different sections of the powder bed in order to avoid mixing the most and least affected particles.

2018 ◽  
Vol 880 ◽  
pp. 297-302
Author(s):  
Gabriel Cătălin Marinescu ◽  
Ştefan Stamin ◽  
Bebe Tică ◽  
Alina Duță

The present paper approaches some of the main problems that appear during the 3D printing manufacturing process of polymer based objects. Printed parts are not always functional due to many possible faults that appear with the 3D printing process. The paper content briefly presents five of the most common problems noticed in polymer printing. The causes and eventual solutions are described based on several experimental tests. The purpose is to analyze the parameter changes that affect quality of printed parts and to give the solutions for avoiding losses during manufacturing.


Author(s):  
Rishi Thakkar ◽  
Yu Zhang ◽  
Jiaxiang Zhang ◽  
Mohammed Maniruzzaman

AbstractThis study demonstrated the first case of combining novel continuous granulation with powder-based pharmaceutical 3-dimensional (3D) printing processes to enhance the dissolution rate and physical properties of a poorly water-soluble drug. Powder bed fusion (PBF) and binder jetting 3D printing processes have gained much attention in pharmaceutical dosage form manufacturing in recent times. Although powder bed-based 3D printing platforms have been known to face printing and uniformity problems due to the inherent poor flow properties of the pharmaceutical physical mixtures (feedstock). Moreover, techniques such as binder jetting currently do not provide any solubility benefits to active pharmaceutical ingredients (APIs) with poor aqueous solubility (>40% of marketed drugs). For this study, a hot-melt extrusion-based versatile granulation process equipped with UV-Vis process analytical technology (PAT) tools for the in-line monitoring of critical quality attributes (i.e., solid-state) of indomethacin was developed. The collected granules with enhanced flow properties were mixed with vinylpyrrolidone-vinyl acetate copolymer and a conductive excipient for efficient sintering. These mixtures were further characterized for their bulk properties observing an excellent flow and later subjected to a PBF-3D printing process. The physical mixtures, processed granules, and printed tablets were characterized using conventional as well as advanced solid-state characterization. These characterizations revealed the amorphous nature of the drug in the processed granules and printed tablets. Further, the in vitro release testing of the tablets with produced granules as a reference standard depicted a notable solubility advantage (100% drug released in 5 minutes at >pH 6.8) over the pure drug and the physical mixture. Our developed system known as DosePlus combines innovative continuous granulation and PBF-3D printing process which can potentially improve the physical properties of the bulk drug and formulations in comparison to when used in isolation. This process can further find application in continuous manufacturing of granules and additive manufacturing of pharmaceuticals to produce dosage forms with excellent uniformity and solubility advantage.Abstract Figure


Author(s):  
Yaqi Zhang ◽  
Vadim Shapiro ◽  
Paul Witherell

Abstract Powder bed fusion (PBF) is a widely used additive manufacturing (AM) technology to produce metallic parts. Understanding the relationships between process parameter settings and the quality of finished parts remains a critical research question. Developing this understating involves an intermediate step: Process parameters, such as laser power and scan speed, influence the ongoing process characteristics, which then affect the final quality of the finished parts. Conventional approaches to addressing those challenges such as powder-based simulations (e.g., discrete element method (DEM)) and voxel-based simulations (e.g., finite element method (FEM)) can provide valuable insight into process physics. Those types of simulations, however, are not well-suited to handle realistic manufacturing plans due to their high computational complexity. Thermal simulations of the PBF process have the potential to implement that intermediate step. Developing accurate thermal simulations, however, is difficult due to the physical and geometric complexities of the manufacturing process. We propose a new, meso-scale, thermal-simulation, which is built on the path-level interactions described by a typical process plan. Since our model is rooted in manufactured geometry, it has the ability to produce scalable, thermal simulations for evaluating realistic process plans. The proof-of-concept simulation result is validated against experimental results in the literature and experimental results from National Institute of Standards and Technology (NIST). In our model, the laser-scan path is discretized into elements, and each element represents the newly melted material. An element-growth mechanism is introduced to simulate the evolution of the melt pool and its thermal characteristics during the manufacturing process. The proposed simulation reduces computational demands by attempting to capture the most important thermal effects developed during the manufacturing process. Those effects include laser-energy absorption, thermal interaction between adjacent elements and elements within the underneath substrate, thermal convection and radiation, and powder melting.


1991 ◽  
Vol 48-49 ◽  
pp. 178-184 ◽  
Author(s):  
A. Ermolieff ◽  
F. Martin ◽  
A. Amouroux ◽  
S. Marthon ◽  
J.F.M. Westendorp

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1391
Author(s):  
Leila Ladani ◽  
Maryam Sadeghilaridjani

Additive manufacturing (AM) as a disruptive technology has received much attention in recent years. In practice, however, much effort is focused on the AM of polymers. It is comparatively more expensive and more challenging to additively manufacture metallic parts due to their high temperature, the cost of producing powders, and capital outlays for metal additive manufacturing equipment. The main technology currently used by numerous companies in the aerospace and biomedical sectors to fabricate metallic parts is powder bed technology, in which either electron or laser beams are used to melt and fuse the powder particles line by line to make a three-dimensional part. Since this technology is new and also sought by manufacturers, many scientific questions have arisen that need to be answered. This manuscript gives an introduction to the technology and common materials and applications. Furthermore, the microstructure and quality of parts made using powder bed technology for several materials that are commonly fabricated using this technology are reviewed and the effects of several process parameters investigated in the literature are examined. New advances in fabricating highly conductive metals such as copper and aluminum are discussed and potential for future improvements is explored.


1990 ◽  
Author(s):  
Anne ERMOLIEFF ◽  
F. MARTIN ◽  
A. AMOUROUX ◽  
S. MARTHON ◽  
J. F. M WESTENDORP

2004 ◽  
Vol 810 ◽  
Author(s):  
Janadass Shanmugam ◽  
Michael Coviello ◽  
Darshak Udeshi ◽  
Wiley P. Kirk ◽  
Meng Tao Nano

ABSTRACTValence mending of a semiconductor surface, such as the Se-passivated Si(001) surface, improves the chemical and thermal stability of the surface as compared to the bare Si(001) surface. In this paper, we report the suppression of Ni silicide formation between Ni and Si(001) through monolayer passivation of Si(001) by Se. Ni was deposited on both Se-passivated and bare Si(001) surfaces. The samples were annealed at temperatures from 400°C to 700°C. Cross-sectional TEM (Transmission Electron Microscopy) revealed that Ni on bare samples reacted with Si at 400°C and formed silicide, whereas Ni on Se-passivated samples did not react with Si at 500°C. Surface composition analysis by XPS (X-Ray Photoelectron Spectroscopy) showed pure Ni surface on Se-passivated samples annealed at 400°C and 500°C, but silicide surface on bare samples annealed at the same temperatures. Hence, Se passivation suppresses the formation of Ni silicide on the Si(001) surface by over 100°C as compared to the bare Si(001) surface. These results may have important implications in source/drain engineering in sub-100 nm Si CMOS (Complementary Metal Oxide Semiconductor) devices.


2021 ◽  
Vol 249 ◽  
pp. 14012
Author(s):  
Koyel Sen ◽  
Tanu Mehta ◽  
Anson W.K.Ma ◽  
Bodhisattwa Chaudhuri

3D printing is emerging as one of the most promising methods to manufacture Pharmaceutical dosage forms as it offers multiple advantages such as personalization of dosage forms, polypill, fabrication of complex dosage forms etc. 3D printing came into existence in 1980s but its use was extended recently to pharmaceutical industry along with the approval of first 3D printed tablet Spritam by FDA in 2015. Spritam was manufactured by Aprecia pharmaceuticals using binder jetting technology. Binder jet 3D printing involves a hopper for powder discharge and printheads for ink jetting. The properties of tablets are highly dependent upon the discharge quality of powder mixture from the hopper and jetting of the ink/binder solution from the printhead nozzle. In this study, numerical models were developed using Discrete element method (DEM) to gain better understanding of the binder jet 3D printing process. The DEM modeling of hopper discharge was performed using in-house DEM code to study the effect of raw material attributes such as powder bed packing density (i.e. particle size, particle density etc) on the printing process, especially during powder bed preparation. This DEM model was further validated experimentally, and the model demonstrated good agreement with experimental results.


Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1544
Author(s):  
Yangyang Zhang ◽  
Na Liu ◽  
Haipeng Xie ◽  
Jia Liu ◽  
Pan Yuan ◽  
...  

The surface composition and morphology of FA0.85MA0.15Pb(I0.85Br0.15)3 films fabricated by the spin-coating method with different concentrations of NH2-POSS were investigated with atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), angle-resolved X-ray photoelectron spectroscopy (AR-XPS), and Fourier transform infrared spectroscopy (FTIR). It was found that the surface composition of the FA0.85MA0.15Pb(I0.85Br0.15)3 films was changed regularly through the interaction between NH2-POSS and the perovskite film. The corresponding surface morphological changes were also observed. When the concentration of NH2-POSS exceeded 10 mg/mL, a lot of cracks on the surface of the perovskite film were observed and the surface morphology was damaged. The surface composition and its distribution can be adjusted by changing the concentration of NH2-POSS and the proper concentration of NH2-POSS can substantially improve the quality of perovskite film.


2017 ◽  
Vol 37 (2) ◽  
pp. 162-169 ◽  
Author(s):  
Julien Gardan

Purpose This paper aims to present a technical approach to evaluate the quality of textures obtained by an inkjet during binder jetting in 3D printing on a powder bed through contours detection to improve the quality of the surface printed according to the result of the assembly between the inkjet and a granular product. Design/methodology/approach The manufacturing process is based on the use of computer-aided design and a 3D printer via binder jetting. Image processing measures the edge deviation of a texture on the granular surface with the possibility of implementing a correction in an active assembly through a “design for manufacturing” (DFM) approach. Example application is presented through first tests. Findings This approach observes a shape alteration of the printed image on a 3D printed product, and the work used the image processing method to improve the model according to the DFM approach. Originality/value This paper introduces a solution for improving the texture quality on 3D printed products realized via binder jetting. The DFM approach proposes an active assembly by compensating the print errors in upstream of a product life cycle.


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