scholarly journals Shaping ceramics through indirect selective laser sintering

2016 ◽  
Vol 22 (3) ◽  
pp. 544-558 ◽  
Author(s):  
Jan Patrick Deckers ◽  
Khuram Shahzad ◽  
Ludwig Cardon ◽  
Marleen Rombouts ◽  
Jozef Vleugels ◽  
...  
Keyword(s):  
Design Methodology ◽  
Dispersion Polymerization ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Powder Synthesis ◽  
Composite Powders ◽  
Content Type ◽  
Production Methods ◽  
Nylon 12 ◽  
Furnace Sintering

Purpose The purpose of this paper is to compare different powder metallurgy (PM) processes to produce ceramic parts through additive manufacturing (AM). This creates the potential to rapidly shape ceramic parts with an almost unlimited shape freedom. In this paper, alumina (Al2O3) parts are produced, as Al2O3 is currently the most commonly used ceramic material for technical applications. Design/methodology/approach Variants of the following PM route, with indirect selective laser sintering (indirect SLS) as the AM shaping step, are explored to produce ceramic parts: powder synthesis, indirect SLS, binder removal and furnace sintering and alternative densification steps. Findings Freeform-shaped Al2O3 parts with densities up to approximately 90 per cent are obtained. Research limitations/implications The resulting Al2O3 parts contain inter-agglomerate pores. To produce higher-quality ceramic parts through indirect SLS, these pores should be avoided or eliminated. Originality/value The research is innovative in many ways. First, composite powders are produced using different powder production methods, such as temperature-induced phase separation and dispersion polymerization. Second, four different binder materials are investigated: polyamide (nylon-12), polystyrene, polypropylene and a carnauba wax – low-density polyethylene combination. Further, to produce ceramic parts with increased density, the following densification techniques are investigated as additional steps of the PM process: laser remelting, isostatic pressing and infiltration.

Preparation and selective laser sintering of nylon-12 coated copper powders

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yi Fu ◽  
Chunze Yan ◽  
Xiao Yang ◽  
Zhufeng Liu ◽  
Peng Chen ◽  
...  
Keyword(s):  
Composite Materials ◽  
Bending Strength ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Precipitation Method ◽  
Slice Thickness ◽  
Composite Powders ◽  
Content Type ◽  
Copper Powders ◽  
Nylon 12

Purpose The purpose of this paper is to prepare metal/polymer composite materials prepared by additive manufacturing (AM) technology. Design/methodology/approach The effect of sintering parameters including laser power, scanning speed and slice thickness on strength and accuracy of selective laser sintering (SLS) parts were analyzed experimentally. Then, the laser sintering mechanism of nylon-12 coated copper was discussed through analyzing the interfacial reaction of nylon-12 and copper. The SLS parts were infiltrated with epoxy resin to meet the strength requirements of injection molding. Findings In this study, mechanical mixed nylon-12/copper and nylon-12 coated copper composite powders were investigated and compared as SLS materials. An effective dissolution–precipitation method was proposed to prepare nylon-12 coated copper powders with better processing and mechanical properties. The bending strength and modulus of fabricated parts after infiltration with epoxy reach 65.3 MPa and 3,200 MPa, respectively. Originality/value The composite materials can be used in the manufacture of injection molds with a conformal cooling channel for the production of common plastics in prototype quantities, showing a broad application prospect in rapid tooling.

Preparation and selective laser sintering of a new nylon elastomer powder

2018 ◽  
Vol 24 (6) ◽  
pp. 1026-1033 ◽  
Author(s):  
Yunsong Shi ◽  
Wei Zhu ◽  
Chunze Yan ◽  
Jinsong Yang ◽  
Zhidao Xia
Keyword(s):  
Particle Size ◽  
Design Methodology ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Precipitation Process ◽  
Content Type ◽  
Dissolution Temperature ◽  
Cooling Method ◽  
Bed Temperature ◽  
Nylon 12

Purpose This study aims to report the preparation, selective laser sintering (SLS) processing and properties of a new nylon elastomer powder. The effects of solvent, dissolution temperature and time and cooling method and speed on the particle size and morphologies of the prepared nylon elastomer powder are investigated. Design/methodology/approach The prepared nylon elastomer power possesses the particle size of around 50 mm and is spherical in shape, indicating that this study provides the feasible dissolution-precipitation process, a distillation cooling method and a suitable solvent to prepare nylon elastomer powders. Findings Compared to pure nylon 12, the nylon elastomer has a lower part bed temperature and a wider sintering window for the SLS process. The wider sintering window indicates the better SLS processibility. The lower part bed temperature is beneficial to the recycling of material and the decrease in the requirement of SLS equipment. Originality/value The nylon elastomer in this study has a lower part bed temperature and a wider sintering window for the SLS process. The wider sintering window indicates better SLS processibility. The lower part bed temperature is beneficial to the recycling of material and the decrease in the requirement of SLS equipment.

Selective laser sintering manufacturing of polycaprolactone bone scaffolds for applications in bone tissue engineering

2015 ◽  
Vol 21 (4) ◽  
pp. 386-392 ◽  
Author(s):  
Alida Mazzoli ◽  
C Ferretti ◽  
A Gigante ◽  
E Salvolini ◽  
M Mattioli-Belmonte
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Design Methodology ◽  
Selective Laser Sintering ◽  
Human Mesenchymal Stem Cells ◽  
Laser Sintering ◽  
Porous Scaffolds ◽  
Content Type ◽  
Skeletal Defects

Purpose – The purpose of this study is to show how selective laser sintering (SLS) manufacturing of bioresorbable scaffolds is used for applications in bone tissue engineering. Design/methodology/approach – Polycaprolactone (PCL) scaffolds were computationally designed and then fabricated via SLS for applications in bone and cartilage repair. Findings – Preliminary biocompatibility data were acquired using human mesenchymal stem cells (hMSCs) assuring a satisfactory scaffold colonization by hMSCs. Originality/value – A promising procedure for producing porous scaffolds for the repair of skeletal defects, in tissue engineering applications, was developed.

Effect of energy input on the UHMWPE fabricating process by selective laser sintering

2017 ◽  
Vol 23 (6) ◽  
pp. 1069-1078 ◽  
Author(s):  
Changhui Song ◽  
Aibing Huang ◽  
Yongqiang Yang ◽  
Zefeng Xiao ◽  
Jia-kuo Yu
Keyword(s):  
Design Methodology ◽  
Energy Input ◽  
Selective Laser Sintering ◽  
Scanning Speed ◽  
Laser Sintering ◽  
Small Scale ◽  
Technological Parameters ◽  
Content Type ◽  
Preheating Temperature ◽  
Ultra High Molecular Weight

Purpose This study aims to achieve customized prosthesis for total joint arthroplasty and total hip arthroplasty. Selective laser sintering (SLS) as additive manufacturing could enable small-scale fabrication of customized Ultra High Molecular Weight Polyethylene (UHMWPE) components; however, the processes for SLS of UHMWPE need to be improved. Design/methodology/approach This paper begins by improving the preheating system of the SLS fabricating equipment and then fabricating cuboids with the same size and cuboids with same volume and different size to study the warpage, demonstrating the effect of the value and uniformity of the preheating temperature on component fabrication. Warpage, density and tensile properties are investigated from the perspective of energy input density. Finally, complicated industrial parts are produced effectively by using optimized technological parameters. Findings The results show that components can be fabricated effectively after the optimization of the SLS technological parameters i.e. the preheating temperature the laser power the scanning interval and the scanning speed. The resulting warpage was found to be less than 0.1 mm along with the density as 83.25 and the tensile strength up to 14.1 Mpa. UHMWPE sample parts with good appearance and strength are obtained after ascertaining the effect of each factor on the fabrication of the sample parts. Originality/value It is very challenging to fabricate UHMWPE sample parts by SLS. This is a new step in the fabrication of customized UHMWPE sample parts.

Correlation between mechanical and surface properties of SLS parts

2014 ◽  
Vol 20 (4) ◽  
pp. 285-290 ◽  
Author(s):  
Grazielle de Oliveira Setti ◽  
Marcelo Fernandes de Oliveira ◽  
Izaque Alves Maia ◽  
Jorge Vicente Lopes da Silva ◽  
Raluca Savu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Surface Properties ◽  
Laser Power ◽  
Design Methodology ◽  
Selective Laser Sintering ◽  
Correlation Coefficients ◽  
Content Type ◽  
Industrial Environment ◽  
Scattering Measurements ◽  
Nylon 12

Purpose – The purpose of this paper is to compare the results from mechanical testing with measurements of surface-dependent properties performed on polyamide parts made by selective laser sintering (SLS) to assess a possible correlation between them. Design/methodology/approach – Fabrication of Nylon 12 (Duraform PA®) samples using different laser power levels and their characterization by tensile testing, roughness and Raman scattering measurements. Findings – Among the surface methods investigated, the results from Raman spectroscopy are the best ones, but methods dependent on surface analysis are not really suitable as indicators of the mechanical properties. The correlation coefficients for linear fitting obtained when the normalized results of mechanical properties are plotted against the surface properties are too low. Furthermore, the ambiguity between surface and mechanical data makes it impossible to use these surface properties for prediction purposes in the industrial environment. Originality/value – Quantitative evaluation and correlation between mechanical properties and surface properties of SLS-made samples.

Study in performance and morphology of polyamide 12 produced by selective laser sintering technology

2018 ◽  
Vol 24 (5) ◽  
pp. 813-820 ◽  
Author(s):  
Junjie Wu ◽  
Xiang Xu ◽  
Zhihao Zhao ◽  
Minjie Wang ◽  
Jie Zhang
Keyword(s):  
Selective Laser Sintering ◽  
Polarized Light ◽  
Chain Scission ◽  
High Energy ◽  
Laser Sintering ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Content Type ◽  
X Ray ◽  
Polyamide 12

Purpose The purpose of this paper is to investigate the effect of selective laser sintering (SLS) method on morphology and performance of polyamide 12. Design/methodology/approach Crystallization behavior is critical to the properties of semi-crystalline polymers. The crystallization condition of SLS process is much different from others. The morphology of polyamide 12 produced by SLS technology was investigated using scanning electron microscopy, polarized light microscopy, differential scanning calorimetry, X-ray diffraction and wide-angle X-ray diffraction. Findings Too low fill laser power brought about bad fusion of powders, while too high energy input resulted in bad performance due to chain scission of macromolecules. There were three types of crystal in the raw powder material, denoted as overgrowth crystal, ring-banded spherulite and normal spherulite. Originality/value In this work, SLS samples with different sintering parameters, as well as compression molding sample for the purpose of comparison, were made to study the morphology and crystal structure of sintered PA12 in detail.

Selection of selective laser sintering materials for different applications

2015 ◽  
Vol 21 (6) ◽  
pp. 630-648 ◽  
Author(s):  
Sunil Kumar Tiwari ◽  
Sarang Pande ◽  
Sanat Agrawal ◽  
Santosh M. Bobade
Keyword(s):  
Process Parameters ◽  
High Performance ◽  
Material Selection ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Optimal Process ◽  
Content Type ◽  
Volume Production ◽  
High Performance Application ◽  
Selection Of

Purpose – The purpose of this paper is to propose and evaluate the selection of materials for the selective laser sintering (SLS) process, which is used for low-volume production in the engineering (e.g. light weight machines, architectural modelling, high performance application, manufacturing of fuel cell, etc.), medical and many others (e.g. art and hobbies, etc.) with a keen focus on meeting customer requirements. Design/methodology/approach – The work starts with understanding the optimal process parameters, an appropriate consolidation mechanism to control microstructure, and selection of appropriate materials satisfying the property requirement for specific application area that leads to optimization of materials. Findings – Fabricating the parts using optimal process parameters, appropriate consolidation mechanism and selecting the appropriate material considering the property requirement of applications can improve part characteristics, increase acceptability, sustainability, life cycle and reliability of the SLS-fabricated parts. Originality/value – The newly proposed material selection system based on properties requirement of applications has been proven, especially in cases where non-experts or student need to select SLS process materials according to the property requirement of applications. The selection of materials based on property requirement of application may be used by practitioners from not only the engineering field, medical field and many others like art and hobbies but also academics who wish to select materials of SLS process for different applications.

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