Development of process efficiency maps for selective laser sintering of polymeric composite powders: Modeling and experimental testing

2018 ◽  
Vol 254 ◽  
pp. 52-59 ◽  
Author(s):  
Fei Shen ◽  
Shangqin Yuan ◽  
Chee Kai Chua ◽  
Kun Zhou
Keyword(s):  
Experimental Testing ◽  
Selective Laser Sintering ◽  
Polymeric Composite ◽  
Laser Sintering ◽  
Process Efficiency ◽  
Composite Powders

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.

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.

Processing-Structure-Property Relations of Polymer-Polymer Composites Formed by Cryogenic Mechanical Alloying for Selective Laser Sintering Applications

2000 ◽  
Vol 625 ◽  
Author(s):  
J. P. Schultz ◽  
J. P. Martin ◽  
R. G. Kander ◽  
C. T. A. Suchicital
Keyword(s):  
Mechanical Alloying ◽  
Polymer Composites ◽  
Effective Means ◽  
Selective Laser Sintering ◽  
Domain Size ◽  
Laser Sintering ◽  
Charge Ratio ◽  
Composite Particles ◽  
Structure Property ◽  
Composite Powders

AbstractCryogenic mechanical alloying (CMA) has been shown to be an effective means for producing composite powders for selective laser sintering (SLS). Unlike composite particles made by a coating process, both phases are continuous throughout the particles formed by CMA. Consolidation of these composite particles via SLS offers the possibility of forming parts with a co-continuous microstructure. In this research, the microstructure of mechanically alloyed polymer-polymer composites for use in the SLS process is investigated using transmission electron microscopy. By varying the charge ratio and milling time of the CMA process, the phase domain size of the resulting composite powder can be manipulated. This ongoing work explores the microstructural evolution as the composite powders are consolidated via SLS into macroscopic parts, as well as the relationships between microstructure and bulk properties.

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.

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