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Article
Publication date: 27 February 2021

Martin Krčma, David Škaroupka, Petr Vosynek, Tomáš Zikmund, Jozef Kaiser and David Palousek

This paper aims to focus on the evaluation of a polymer concrete as a three-dimensional (3D) printing material. An associated company has developed plastic concrete made…

Abstract

Purpose

This paper aims to focus on the evaluation of a polymer concrete as a three-dimensional (3D) printing material. An associated company has developed plastic concrete made from reused unrecyclable plastic waste. Its intended use is as a construction material.

Design/methodology/approach

The concrete mix, called PolyBet, composed of polypropylene and glass sand, is printed by the fused deposition modelling process. The process of material and parameter selection is described. The mechanical properties of the filled material were compared to its cast state. Samples were made from castings and two different orientations of 3D-printed parts. Three-point flex tests were carried out, and the area of the break was examined. Computed tomography of the samples was carried out.

Findings

The influence of the 3D printing process on the material was evaluated. The mechanical performance of the longitudinal samples was close to the cast state. There was a difference in the failure mode between the states, with cast parts exhibiting a tougher behaviour, with fractures propagating in a stair-like manner. The 3D-printed samples exhibited high degrees of porosity.

Originality/value

The results suggest that the novel material is a good fit for 3D printing, with little to no degradation caused by the process. Layer adhesion was shown to be excellent, with negligible effect on the finished part for the longitudinal orientation. That means, if large-scale testing of buildability is successful, the material is a good fit for additive manufacturing of building components and other large-scale structures.

Details

Rapid Prototyping Journal, vol. 27 no. 3
Type: Research Article
ISSN: 1355-2546

Keywords

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Article
Publication date: 18 October 2018

David Palousek, Martin Kocica, Libor Pantelejev, Lenka Klakurkova, Ladislav Celko, Daniel Koutny and Jozef Kaiser

Materials with a high thermal conductivity, such as Cu-alloys hold the most interest to the plastic moulding industry. Additive manufacturing (AM), especially selective…

Abstract

Purpose

Materials with a high thermal conductivity, such as Cu-alloys hold the most interest to the plastic moulding industry. Additive manufacturing (AM), especially selective laser melting (SLM) of metals, allows the production of parts with complicated internal cooling and increased production efficiency. The portfolio of alloys for metal AM is limited and still missing process parameters for the processing of copper alloys. This paper aims to preview the process parameters of high-strength alloy Cu7.2Ni1.8Si1Cr processed by SLM.

Design/methodology/approach

An experimental approach is adopted to investigate porosity and mechanical properties of SLM specimens and its comparison with standard material AMPCOLOY 944. Optimization of porosity was performed using line and cube specimens; mechanical properties and microstructure were evaluated by tensile testing and metallography.

Findings

Optimum processing parameters for fabrication of Cu-alloy specimens with a relative density of 99.95 per cent were identified, and no cracks were detected. Mechanical testing of SLM specimens showed the ultimate tensile strength, proof stress of 0.2 and elongation of 380, 545 MPa and 16.9 per cent. The alloy is suitable for laser AM, thanks to its processability at a relatively high laser scanning speeds and thus its promising price of part/costs ratio.

Research limitations/implications

The paper describes the initial state of research – the follow-up tests focussed on mechanical testing, fatigue and statistical evaluation need to be conducted. The process parameters are developed only for bulk geometry – optimal setup for lattice structures and thin walls has not been explored yet.

Practical implications

The research findings in this work could be used for production of 3D printed parts and after the tuning of additional parameters, e.g. for up- and down-skin zones, could be used for special application such as energy exchange.

Originality/value

This work produces the processing of new material suitable for laser AM. Cu7.2Ni1.8Si1Cr alloy could be the prospective material from the group of Cu alloys suitable for moulds manufacturing and thermal applications.

Details

Rapid Prototyping Journal, vol. 25 no. 2
Type: Research Article
ISSN: 1355-2546

Keywords

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Article
Publication date: 30 September 2019

Ondřej Vaverka, Daniel Koutny and David Palousek

This paper aims to present the design process, manufacturing and testing of a prototype of an axle carrier for Formula Student race car. The axle carrier is topologically…

Abstract

Purpose

This paper aims to present the design process, manufacturing and testing of a prototype of an axle carrier for Formula Student race car. The axle carrier is topologically optimized and additively manufactured using selective laser melting (SLM).

Design/methodology/approach

The shape of the axle carrier was created in three design stages using topology optimization and four additional design stages based on finite element calculations and experimental testing. Topology optimization was performed on the basis of relevant load cases. The sixth design stage was manufactured by SLM and then tested on a loading device together with photogrammetry measurement to obtain the real deformation. Measured deformations were compared with deformation calculated by the finite element method (FEM), verified and experiences used in the last design stage.

Findings

An additively manufactured axle carrier has a minimal safety factor of 1.2 according to experimental testing. The weight and maximal deformations are comparable with the milled part, although the material has about 50 per cent worse yield strength. The topologically optimized axle carrier proved big potential in the effective distribution of material and the improvement of toughness.

Practical implications

This paper helps the Formula Student team to enhance the driving performance while keeping low weight. It also improves further development and upgrading of the race car.

Originality/value

The whole design of the topologically optimized part was investigated – from estimation of the loads to experimental verification of FEM analysis on real part.

Details

Rapid Prototyping Journal, vol. 25 no. 9
Type: Research Article
ISSN: 1355-2546

Keywords

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Article
Publication date: 14 January 2014

David Palousek, Jiri Rosicky, Daniel Koutny, Pavel Stoklásek and Tomas Navrat

– The purpose of this paper is to describe a manufacturing methodology for a wrist orthosis. The case study aims to offer new approaches in the area of human orthoses.

Abstract

Purpose

The purpose of this paper is to describe a manufacturing methodology for a wrist orthosis. The case study aims to offer new approaches in the area of human orthoses.

Design/methodology/approach

The article describes the utilization of rapid prototyping (RP), passive stereo photogrammetry and software tools for the orthosis design process. This study shows the key points of the design and manufacturing methodology. The approach uses specific technologies, such as 3D digitizing, reverse engineering and polygonal-surface software, FDM RP and 3D printing.

Findings

The results show that the used technologies reflect the patient's requirements and also they could be an alternative solution to the standard method of orthosis design.

Research limitations/implications

The methodology provides a good position for further development issues.

Practical implications

The methodology could be usable for clinical practice and allows the manufacturing of the perfect orthosis of the upper limb. The usage of this methodology depends on the RP system and type of material.

Originality/value

The article describes a particular topical problem and it is following previous publications in the field of human orthoses. The paper presents the methodology of wrist orthosis design and manufacturing. The paper presents an alternative approach applicable in clinical practice.

Details

Rapid Prototyping Journal, vol. 20 no. 1
Type: Research Article
ISSN: 1355-2546

Keywords

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