Experimental study on the variance of mechanical properties of polyamide 6 during multi-layer sintering process in selective laser sintering

2018 ◽  
Vol 101 (5-8) ◽  
pp. 1227-1234 ◽  
Author(s):  
Zhicheng Ling ◽  
Jinzhe Wu ◽  
Xiang Wang ◽  
Xiaofeng Li ◽  
Jinjin Zheng
Author(s):  
Jie Niu ◽  
Hui Leng Choo ◽  
Wei Sun

The availability of additive manufacturing technologies in particular the selective laser sintering process has enabled the fabrication of high strength, lightweight and complex cellular lattice structures. In this study, the effective mechanical properties of selective laser sintering produced periodic lattice structures were investigated. Three different types of lattice structures were designed by repeating three types of open-form unit cells consisting of triangular prism, square prism and hexagonal prism. A novel approach of creating the complex and conformable lattice structures using traditional modelling software such as Creo® proposed by the authors was used. Based on the predesigned lattice structures, finite element analysis was carried out to evaluate the mechanical properties of these structures. For the experimental study, nylon samples were printed using a plastic selective laser sintering system and tested using a universal testing machine. Finite element analysis results show that lattice structures with triangular prism perform better than the other two prisms in terms of Young’s modulus to relative density ratio. Tensile tests results show good conformance with the results obtained from finite element analysis.


2020 ◽  
Vol 184 ◽  
pp. 01047 ◽  
Author(s):  
Pankaj Kumar ◽  
Gazanfar Mustafa Ali syed

Additive manufacturing (also known as 3D printing) process is an emerging technique for the fabrication of biomedical components. Selective laser sintering or melting is one of the widely used additive printing technology for manufacturing of metallic and non-metallic components used in the industry. This review paper presents, a summary of the published research papers on the fabrication of biomedical components using selective laser sintering technique. Therefore, author meticulously attempted to investigate individual biocompatible material-wise review which includes Ti6Al4V, Ti-7.5 Mo alloy, β-Ti35Zr28Nb, PEEK, PA2200, and Polyamide/Hydroxyapatite. In addition, this article also explores the effects of the various laser sintering process parameters such as laser power, scanning speed, density of the material on the mechanical properties, tribological properties, porosity and surface roughness of the fabricated alloy. Moreover, the author also investigated challenges and future prospective of the laser processing of biomedical implants.


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.


2018 ◽  
Vol 8 (12) ◽  
pp. 2383 ◽  
Author(s):  
Zhehan Chen ◽  
Xianhui Zong ◽  
Jing Shi ◽  
Xiaohua Zhang

Selective laser sintering (SLS) is an additive manufacturing technology that can work with a variety of metal materials, and has been widely employed in many applications. The establishment of a data correlation model through the analysis of temperature field images is a recognized research method to realize the monitoring and quality control of the SLS process. In this paper, the key features of the temperature field in the process are extracted from three levels, and the mathematical model and data structure of the key features are constructed. Feature extraction, dimensional reduction, and parameter optimization are realized based on principal component analysis (PCA) and support vector machine (SVM), and the prediction model is built and optimized. Finally, the feasibility of the proposed algorithms and model is verified by experiments.


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