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.

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 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.

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.

Numerical modeling and experimental verification of the composite material of PA12/HA with parameterized random distribution in selective laser sintering

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Junchao Li ◽  
Yanan Yang ◽  
Ze Zhao ◽  
Ran Yan
Keyword(s):  
Composite Material ◽  
Random Distribution ◽  
Mechanical Performance ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Vital Role ◽  
Physical Parameters ◽  
Fe Model ◽  
Content Type ◽  
Stress Changes

Purpose The purpose of this study is to establish a finite element (FE) model with the random distribution of the Nylon12/hydroxyapatite (PA12/HA) composite material in selective laser sintering (SLS) process for considering the material anisotropy, which aims to obtain the law of temperature and stress changes in PA12/HA sintering. Design/methodology/approach By using python script in Abaqus, the FE model is established in which the two materials are randomly distributed and are assigned to their intrinsic temperature-dependent physical parameters. Molten pool sizes at various process parameters were evaluated in terms of numerical simulation and scanning electron microscope analysis, identifying a good agreement between them. Evaluation of temperature and stress distribution under the condition of different HA contents was also conducted. Findings It shows that the uneven distribution and quantity of HA powder play a vital role in stress concentration and temperature increase. Additionally, the influence of HA addition on the mechanical performance of SLS-fabricated parts shows that it is conducive to improve compressive strength when the HA ratio is less than 5% because an excess of HA powder tends to bring about a certain amount of microspores resulting in a decrease in part density. Originality/value The FE model of the PA12/HA composite material with parameterized random distribution in SLS can be applied in other similar additive manufacturing technologies. It provides a feasible guideline for the numerical analysis of properties of composite materials.

PREPARATION OF Cu-SiO2/PA12 COMPOSITE POWDERS BY ELECTROLESS PLATING FOR USE IN SLS PROCESSING

2019 ◽  
Vol 26 (09) ◽  
pp. 1950055
Author(s):  
CHENGMEI GUI ◽  
ZHENMING CHEN ◽  
CHENGUANG YAO ◽  
GUISHENG YANG
Keyword(s):  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Composite Particles ◽  
Sintering Behavior ◽  
Contact Interface ◽  
Composite Powders ◽  
Copper Particles ◽  
Dimensional Precision ◽  
Composite Plating ◽  
Sintering Neck

In this work, SiO2-encapsulated copper particles/PA12 (Cu-SiO2/PA12) composite powders were prepared by electroless composite plating, and the laser sintering behavior was investigated. Results showed that Cu, Cu2O, CuO, and SiO2 (Cu-SiO2) composite particles were plated on the surface of KH550-modified PA12 powders. The Cu-SiO2 particles existed independently on PA12 surface, and the size was around 200 nm. The melting temperature and crystallization temperature of Cu-SiO2/PA12 composite powders were 183∘C and 150∘C. The results indicate that the selective laser sintering (SLS) process involved the contact of Cu-SiO2/PA12 powders, the formation of sintering neck, the growth of sintering neck, and the formation of fused solid. The Cu-SiO2 composite particles uniformly dispersed in the part due to surface tension, and the contact interface was good due to their similar polarity. The Cu-SiO2/PA12 SLS parts had excellent dimensional precision. The tensile strength of the 15[Formula: see text]W-sintered Cu-SiO2/PA12 specimen was 48[Formula: see text]MPa.

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