Authors: Damjan Klobcar, Sebastian Balos, Matija Busic, Aleksija Duricd, Maja Lindic, Aljaz Scetinec

Abstract

The paper presents an overview of metal additive manufacturing technologies. The emphasis is on unconventional emerging technologies with firm background on welding technologies such as Ultrasonic Additive Manufacturing, Friction Additive Manufacturing, Thermal Spray Additive Manufacturing, Resistance Additive Manufacturing and Wire and Arc Additive Manufacturing. The particular processes are explained in detail and their advantages and drawbacks are presented. Attention is made on materials used, possibilities to produce multi-material products and functionally graded materials, and typical applications of currently developed technologies. The state-of-the-art on the Wire and Arc Additive Manufacturing is presented in more detail due to high research interests, it’s potential and widespread. The main differences between different arc additive manufacturing technologies are shown. An influence of processing parameters is discussed with respect to process stability and process control. The challenges related to path planning are shown together with the importance of post-processing. The main advantage of presented technologies is their ability of making larger and multi-material parts, with high deposition rate, which is difficult to achieve using conventional additive technologies.

Key words: Wire arc additive manufacturing; Ultrasonic additive manufacturing; Friction additive manufacturing; Thermal spray additive manufacturing; Resistance additive manufacturing

DOI: 10.24867/ATM-2020-2-001

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Authors: Oladele Isiaka Oluwole, Babarinde Opeyemi Emmanuel, Agbabiaka Okikiola Ganiu, Adegun Micheal Hope, Adelani Samson Oluwagbenga, Balogun Oluwayomi Peter

Abstract

The development of hybrid cellulosic-keratinous fibers reinforced epoxy composites was investigated in this study. Hybrid composites were fabricated by mixing coir fiber (CF) and chicken feather fiber (CFF) with the epoxy matrix in a randomly dispersed approach. The mechanical properties such as tensile, flexural and hardness properties were determined. Also, wear property, thermal conductivity and moisture absorption potentials of the developed composites were studied while the surface morphology of the composite fracture surface was examined using scanning electron microscopy (SEM). The results revealed that all the selected properties were improved compared to the unreinforced epoxy matrix. Sample with 1% CF and 2% CFF gave the optimum results and the combination of good mechanical, wear, thermal insulating and moisture resistance properties. It was discovered that higher volume of CFF in synergy with low volume of CF was responsible for performance. The results revealed that the materials can be used in automobile due to the inclusion of light-weight bio-fibers that gave good insulating properties in epoxy composites in conjunction with good mechanical, wear and moisture resistance.

Key words: Bio-fiber; ecofriendly materials; green composites; agro-wastes; pollution control

DOI: 10.24867/ATM-2020-2-002

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Authors: Miloš Pjević, Mihajlo Popović, Ljubodrag Tanović, Goran Mladenović

Abstract

With fast growing industry in the field of additive technology, possibilities of DIY (Do It Yourself) projects grow as well. This also gives the opportunity for non-expert's users to project and develop some complex products on their own. The reaction was global overflow of the 3D printer's sale worldwide. If we look in the long term, environmental pollution caused by their disposed polymer is their biggest flaw. Recycling process sometimes can be very expensive, and in certain cases unavailable for some users. In this paper, low-cost recycling system for materials that are most commonly used for FDM/FFF method is presented. The main goal was to reduce environmental pollution and 3D printing costs by presenting the possibility of making its own polymer made of scrape plastic. Moreover, this allows users to make their own recipe by mixing different types of scrape polymer, or adding reinforcing material such as chopped dry fibre, metal powder, etc.

Key words: Recycling, Environmental Pollution, Additive Technology, FDM/FFF, Filament Extruder

DOI: 10.24867/ATM-2020-2-003

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Authors: Kayode I. Fesomade, Damilola D. Alewi, Saliu O. Seidu, Sheriff O. Saka, Bonaventure I. Osuide, Godwin C. Ebidame, Marybeth C. Ugoh, Damilola O. Animasaun

Abstract

This study investigates the influence of palm kernel shell ash (PKSA) on mechanical and wear properties of white cast iron (WCI) particularly its influence on its microstructure, elemental composition, hardness and wear resistance. The PKSA was characterized to determine its elemental composition, and it was found to contain high amount of silicon (Si) and iron (Fe) followed by calcium (Ca) and other trace elements. The cast iron was cast into rods of specific dimension with sand casting method using rotary furnace to re-melt cast iron scrap. The WCI rods were then cut into bits for the various test. Heat treatment operation was carried out to determine its properties. Upon completion of the examinations, it was found that the PKSA increased the cementite phase within the matrix of the cast iron, and reduced the pearlitic phase and graphite formation, which gave it increased hardness, and perfect wear resistance due to the increment in carbon content and reduction in silicon content. Also, upon heat treatment, it was found that the PKSA reduced the pearlitic phase within the matrix of the cast iron, increases the formation of transformed ledeburites, austenitic dendrites and tempered graphite, which lead to increased machinability and ductility as well as to reduced hardness, and wear resistance when compared to non-heat treated samples.

Key words: Microstructure; Heat treatment; Wear Resistance; Hardness; palm kernel shell ash (PKSA)

DOI: 10.24867/ATM-2020-2-004

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Authors: Svetomir Simonović

Abstract

The work deals with possibilities of molecular level device production for use in binary data storage and in performing basic logical operations needed for binary data processing. Method of obtaining molecular logic gates through bottom-up production approach, that is, the method of transition from liquid state to solid state nanodevices, has been outlined. In addition, methods of obtaining some devices through combination of top-down and bottom-up production methods, that is the methods of building single nano particle transistors, have been depicted. The devices production justification has been considered through their characteristics such as the devices packing density, switching speed, device ease of addressing, device ease of production, and device concatenability

DOI: 10.24867/ATM-2020-2-005

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