scholarly journals The influence of build orientation on the mechanical properties of medical implants made from PA 2200 by Selective Laser Sintering

2017 ◽  
Vol 112 ◽  
pp. 03009 ◽  
Author(s):  
Răzvan Păcurar ◽  
Ancuţa Păcurar ◽  
Anna Petrilak
2019 ◽  
Vol 34 ◽  
pp. 3-9
Author(s):  
Alexandra Nitoi ◽  
Mihai Alin Pop ◽  
Ting Ting Peng ◽  
Tibor Bedő ◽  
Sorin Ion Munteanu ◽  
...  

Additive manufacturing [AM] is a type of production technology characterized by the additive nature of stacking and unifying individual layers, with the main advantage that parts with complex geometries can easily be obtained, compared to conventional production methods. Due to its working principle, i.e. stacking layers, obtained by melting and solidification, the mechanical characteristics of the built part might be influenced by the build orientation chosen for the specific part. The mechanical behavior, cyclic deformation and fatigue behaviors of additively manufactured metallic parts as compared to their counterparts obtained by conventional processing technologies was reported to be highly dependent on the build orientation. The aim of this study was to assess whether the build orientation will have an impact on the mechanical properties of parts built by Selective Laser Sintering, using polyamide powder as raw material. Samples were built at various inclination degrees, and were further tested in terms of bending, compressive, impact and hardness tests. It was observed that the build orientation has a significant effect on the mechanical properties of parts additively manufactured from polyamide, compared to the behavior presented on the technical sheet of the material, provided by the manufacturer. Keywords: additive manufacturing, mechanical properties, build orientation, Selective Laser Sintering


2020 ◽  
Vol 26 (6) ◽  
pp. 1103-1112
Author(s):  
Saleh Ahmed Aldahash ◽  
Abdelrasoul M. Gadelmoula

Purpose The cement-filled PA12 manufactured by selective laser sintering (SLS) offers desirable mechanical properties; however, these properties are dependent on several fabrication parameters. As a result, SLS prototypes may exhibit orthotropic mechanical properties unless properly oriented in build chamber. This paper aims to evaluate the effects of part build orientation, laser energy and cement content on mechanical properties of cement-filled PA12. Design/methodology/approach The test specimens were fabricated by SLS using the “DTM Sinterstation 2000” system at which the specimens were aligned along six different orientations. The scanning speed was 914mm/s, scan spacing was 0.15mm, layer thickness was 0.1mm and laser power was 4.5–8Watt. A total of 270 tensile specimens, 270 flexural specimens and 135 compression specimens were manufactured and the tensile, compression and flexural properties of fabricated specimens were evaluated. Findings The experiments revealed orientation-dependent (orthotropic) mechanical properties of SLS cement-filled PA12 and confirmed that the parts with shorter scan vectors have enhanced flexural strength as compared with longer scan vectors. The maximum deviations of ultimate tensile strength, compressive strength and flexural modulus along the six orientations were 32%, 26% and 36%, respectively. Originality/value Although part build orientation is a key fabrication parameter, very little was found in open literature with contradictory findings about its effect on mechanical properties of fabricated parts. In this work, the effects of build orientation when combined with other fabrication parameters on the properties of SLS parts were evaluated along six different orientations.


2019 ◽  
Vol 9 (7) ◽  
pp. 1308 ◽  
Author(s):  
Rob Kleijnen ◽  
Manfred Schmid ◽  
Konrad Wegener

This work describes the production of a spherical polybutylene terephthalate (PBT) powder and its processing with selective laser sintering (SLS). The powder was produced via melt emulsification, a continuous extrusion-based process. PBT was melt blended with polyethylene glycol (PEG), creating an emulsion of spherical PBT droplets in a PEG matrix. Powder could be extracted after dissolving the PEG matrix phase in water. The extrusion settings were adjusted to optimize the size and yield of PBT particles. After classification, 79 vol. % of particles fell within a range of 10–100 µm. Owing to its spherical shape, the powder exhibited excellent flowability and packing properties. After powder production, the width of the thermal processing (sintering) window was reduced by 7.6 °C. Processing of the powder on a laser sintering machine was only possible with difficulties. The parts exhibited mechanical properties inferior to injection-molded specimens. The main reason lied in the PBT being prone to thermal degradation and hydrolysis during the powder production process. Melt emulsification in general is a process well suited to produce a large variety of SLS powders with exceptional flowability.


2019 ◽  
Vol 290 ◽  
pp. 08010
Author(s):  
Karolina Karolewska ◽  
Bogdan Ligaj

The most commonly used technology among the additive manufacturing is Direct Metal Laser Sintering (DMLS). This process is based on selective laser sintering (SLS). The method gained its popularity due to the possibility of producing metal parts of any geometry, which would be difficult or impossible to obtain by the use of conventional manufacturing techniques. Materials used in the elements manufacturing process are: titanium alloys (e.g. Ti6Al4V), aluminium alloy AlSi10Mg, etc. Elements printed from Ti6Al4V titanium alloy find their application in many industries. Details produced by additive technology are often used in medicine as skeletal, and dental implants. Another example of the DMLS elements use is the aerospace industry. In this area, the additive manufacturing technology produces, i.a. parts of turbines. In addition to the aerospace and medical industries, DMLS technology is also used in motorsport for exhaust pipes or the gearbox parts. The research objects are samples for static tests. These samples were made of Ti6Al4V alloy by the DMLS method and the rolling method from a drawn rod. The aim of the paper is the mechanical properties comparative analysis of the Ti6Al4V alloy produced by the DMLS method under static loading conditions and microstructure analysis of this material.


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