Evaluation of tensile strength of 3D printed objects with FDM process on RepRap platform

The manufacture of polyetheretherketone/hydroxyapatite (PEEK/HA) composites is seen as a viable approach to help enhance direct bone apposition in orthopaedic implants. A range of methods have been used to produce composites, including Selective Laser Sintering and injection moulding. Such techniques have drawbacks and lack flexibility to manufacture complex, custom-designed implants. 3D printing gets around many of the restraints and provides new opportunities for innovative solutions that are structurally suited to meet the needs of the patient. This work reports the direct 3D printing of extruded PEEK/HA composite filaments via a Fused Filament Fabrication (FFF) approach. In this work samples are 3D printed by a custom modified commercial printer Ultimaker 2+ (UM2+). SEM-EDX and µCT analyses show that HA particles are evenly distributed throughout the bulk and across the surface of the native 3D printed samples, with XRD highlighting up to 50% crystallinity and crystalline domains clearly observed in SEM and HR-TEM analyses. This highlights the favourable temperature conditions during 3D printing. The yield stress and ultimate tensile strength obtained for all the samples are comparable to human femoral cortical bone. The results show how FFF 3D printing of PEEK/HA composites up to 30 wt% HA can be achieved.

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The Impact of Slicing Softwares on the Mechanical Properties of 3D Printed Parts

International Journal of Recent Technology and Engineering - 2 ◽

10.35940/ijrte.b3668.079220 ◽

2020 ◽

Vol 9 (2) ◽

pp. 487-494

Keyword(s):

Mechanical Properties ◽

Surface Roughness ◽

Tensile Strength ◽

Ultimate Tensile Strength ◽

3D Printer ◽

Stl File ◽

3D Printed ◽

Intersection Curves ◽

The Impact

“Slicing tool” or “Slicing Software” computes the intersection curves of models and slicing planes. They improve the quality of the model being printed when given in the form of STL file. Upon analyzing a specimen that has been printed using two different slicing tools, there was a drastic variation on account of the mechanical properties of the specimen. The ultimate tensile strength and the surface roughness of the material vary from one tool to another. This paper reports an investigation and analysis of the variation in the ultimate tensile strength and the surface roughness of the specimen, given that the 3D printer and the model being printed is the same, with a variation of usage of slicing software. This analysis includes ReplicatorG, Flashprint as the two different slicing tools that are used for slicing of the model. The variation in the ultimate tensile strength and the surface roughness are measured and represented statistically through graphs. An appropriate decisive conclusion was drawn on the basis of the observations and analysis of the experiment on relevance to the behavior and mechanical properties of the specimen.

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Investigation on the Effect of Build Orientation and Heat Treatment on Tensile Strength and Fracture Mechanism of FDM 3D Printed PLA

Lecture Notes in Mechanical Engineering - iMEC-APCOMS 2019 ◽

10.1007/978-981-15-0950-6_70 ◽

2019 ◽

pp. 461-465

Author(s):

Nanang Fatchurrohman ◽

Nurul Najihah Najlaa Noor Hamdan ◽

Mebrahitom Asmelash Gebremariam ◽

Kushendarsyah Saptaji

Keyword(s):

Heat Treatment ◽

Tensile Strength ◽

Fracture Mechanism ◽

Build Orientation ◽

3D Printed

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Superior Mechanical Behavior and Fretting Wear Resistance of 3D-Printed Inconel 625 Superalloy

Applied Sciences ◽

10.3390/app8122439 ◽

2018 ◽

Vol 8 (12) ◽

pp. 2439 ◽

Cited By ~ 8

Author(s):

Yong Gao ◽

Mingzhuo Zhou

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Wear Resistance ◽

Additive Manufacturing ◽

High Hardness ◽

Fretting Wear ◽

Inconel 625 ◽

3D Printed ◽

Inconel 625 Superalloy ◽

Electron Beam Selective Melting

Additive manufacturing (AM) nickel-based superalloys have been demonstrated to equate or exceed mechanical properties of cast and wrought counterparts but their tribological potentials have not been fully realized. This study investigates fretting wear behaviors of Inconel 625 against the 42 CrMo4 stainless steel under flat-on-flat contacts. Inconel 625 is prepared by additive manufacturing (AM) using the electron beam selective melting. Results show that it has a high hardness (335 HV), superior tensile strength (952 MPa) and yield strength (793 MPa). Tribological tests indicate that the AM-Inconel 625 can suppress wear of the surface within a depth of only ~2.4 μm at a contact load of 106 N after 2 × 104 cycles. The excellent wear resistance is attributed to the improved strength and the formation of continuous tribo-layers containing a mixture of Fe2O3, Fe3O4, Cr2O3 and Mn2O3.

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Influence of Filling Strategies on the Tensile Strength and Anisotropic Properties of Droplet-Based 3D-Printed Parts

2018 IEEE International Conference on Robotics and Biomimetics (ROBIO) ◽

10.1109/robio.2018.8665190 ◽

2018 ◽

Cited By ~ 1

Author(s):

Konstantin Struebig ◽

Felix Diller ◽

Tim C. Lueth

Keyword(s):

Tensile Strength ◽

Anisotropic Properties ◽

3D Printed

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Anisotropy Evaluation of Different Raster Directions, Spatial Orientations, and Fill Percentage of 3D Printed PETG Tensile Test Specimens

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.821.167 ◽

2019 ◽

Vol 821 ◽

pp. 167-173 ◽

Cited By ~ 5

Author(s):

Muammel M. Hanon ◽

Róbert Marczis ◽

László Zsidai

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Tensile Test ◽

Fused Deposition Modelling ◽

Elongation At Break ◽

Know How ◽

Fused Deposition ◽

Test Pieces ◽

3D Printed ◽

Fill Percentage

In this paper, the mechanical properties of Polyethylene terephthalate-glycol (PETG) tensile test specimens have been investigated. The test pieces were prepared using fused deposition modelling (FDM) 3D printing technology. Three print settings were examined which are: raster direction angles, print orientations, and infill percentage and patterns in order to evaluate the anisotropy of objects when employing FDM print method. The variations in stress-strain curves, tensile strength values and elongation at break among the tested samples were studied and compared. Illustration for the broken specimens after the tensile test was accomplished to know how the test pieces printed with various parameters were fractured. A comparison with some previous results regarding the elongation at break has been carried out.

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Development and Characterization of a 3D Printed Cocoa Bean Shell Filled Recycled Polypropylene for Sustainable Composites

Polymers ◽

10.3390/polym13183162 ◽

2021 ◽

Vol 13 (18) ◽

pp. 3162

Author(s):

Maria A. Morales ◽

Alejandro Maranon ◽

Camilo Hernandez ◽

Alicia Porras

Keyword(s):

Tensile Strength ◽

3D Printing ◽

Failure Mechanisms ◽

Industrial Wastes ◽

Cocoa Bean ◽

Recycled Polypropylene ◽

Raster Angle ◽

3D Printed ◽

Natural Filler

Natural filler-based composites are an environmentally friendly and potentially sustainable alternative to synthetic or plastic counterparts. Recycling polymers and using agro-industrial wastes are measures that help to achieve a circular economy. Thus, this work presents the development and characterization of a 3D printing filament based on recycled polypropylene and cocoa bean shells, which has not been explored yet. The obtained composites were thermally and physically characterized. In addition, the warping effect, mechanical, and morphological analyses were performed on 3D printed specimens. Thermal analysis exhibited decreased thermal stability when cacao bean shell (CBS) particles were added due to their lignocellulosic content. A reduction in both melting enthalpy and crystallinity percentage was identified. This is caused by the increase in the amorphous structures present in the hemicellulose and lignin of the CBS. Mechanical tests showed high dependence of the mechanical properties on the 3D printing raster angle. Tensile strength increased when a raster angle of 0° was used, compared to specimens printed at 90°, due to the load direction. Tensile strength and fracture strain were improved with CBS addition in specimens printed at 90°, and better bonding between adjacent layers was achieved. Electron microscope images identified particle fracture, filler-matrix debonding, and matrix breakage as the central failure mechanisms. These failure mechanisms are attributed to the poor interfacial bonding between the CBS particles and the matrix, which reduced the tensile properties of specimens printed at 0°. On the other hand, the printing process showed that cocoa bean shell particles reduced by 67% the characteristic warping effect of recycled polypropylene during 3D printing, which is advantageous for 3D printing applications of the rPP. Thereby, potential sustainable natural filler composite filaments for 3D printing applications with low density and low cost can be developed, adding value to agro-industrial and plastic wastes.

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Cracking Patterns of Brittle Hemispherical Domes: an Experimental Study

Frattura ed Integrità Strutturale ◽

10.3221/igf-esis.59.20 ◽

2021 ◽

Vol 16 (59) ◽

pp. 265-310

Author(s):

Siwen Cao ◽

Andras A. Sipos

Keyword(s):

Experimental Study ◽

Tensile Strength ◽

Size Distribution ◽

Crack Formation ◽

Fragmentation Model ◽

Track Record ◽

Hemispherical Dome ◽

3D Printed ◽

Loading Tests ◽

Cracking Pattern

Crack formation in hemispherical domes is a distinguished problem in structural mechanics. The safety of cracked domes has a long track record; the evolution of the cracking pattern received less attention. Here, we report displacement-controlled loading tests of brittle hemispherical dome specimens, including the evolution of the meridional cracking pattern. The 27 investigated specimens, 20 cm in diameter, were prepared in 3D printed molds, and their material is one of the three mixtures of gypsum and cement. We find that neither the (limited) tensile strength nor the exact value of the thickness significantly affects the statistical description of the cracking pattern, i.e., the cracking phenomenon is robust. The maximal number of the meridional cracks never exceeds seven before the fragments’ disintegration (collapse). We find that the size distribution of the fragments exhibits a lognormal distribution. The evolution is reflected in the load-displacement diagrams recorded in the test, too, as significant drops in the force are accompanied by an emergence of one or more new cracks, reflecting the brittle nature of the phenomenon. A simple, stochastic fragmentation model, in which a segment is fragmented at either in the middle or at the fourth point, fairly recovers the observed size distribution.

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Investigating mechanical properties of 3D printed parts manufactured in different orientations on Multijet printer

10.21203/rs.3.rs-247844/v1 ◽

2021 ◽

Author(s):

Ramesh Chand ◽

Vishal S Sharma ◽

Trehan Rajeev

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Mechanical Behavior ◽

Polymer Material ◽

Polymeric Materials ◽

Tensile Behavior ◽

Jet Printing ◽

3D Printed

Abstract Polymer material based products in the engineering field are most widely produced by the multi jet printing (MJP). These products impart inherent benefits in manufacturing intricate contours and shapes at less additional expenses. This emphasizes the importance of studying the mechanical behavior of the manufactured parts, using polymeric materials in different orientations. In this investigation density, tensile behavior & hardness were studied for 3D-printed parts produced in four different orientations (A, B, C and D). It is found that for the best mechanical properties part should be fabricated using orientation ‘A’. Furthermore, for density and tensile strength part should not be fabricated using orientation ‘C’. Also in case of hardness part should not be fabricated in orientation ‘B’.

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