Enhancement mechanism of mechanical performance of highly porous mullite ceramics with bimodal pore structures prepared by selective laser sintering

2019 ◽  
Vol 776 ◽  
pp. 486-494 ◽  
Author(s):  
An-Nan Chen ◽  
Meng Li ◽  
Jia-Min Wu ◽  
Li-Jin Cheng ◽  
Rong-Zhen Liu ◽  
...  
Author(s):  
Tortorici Martina ◽  
Gayer Christoph ◽  
Torchio Alessandro ◽  
Cho Simone ◽  
Schleifenbaum Johannes Henrich ◽  
...  

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Junchao Li ◽  
Yanan Yang ◽  
Ze Zhao ◽  
Ran Yan

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.


2020 ◽  
Vol 46 (6) ◽  
pp. 8438-8443 ◽  
Author(s):  
Xiangong Deng ◽  
Wanchun Zhang ◽  
Jiaqiang Yin ◽  
Chaoheng Deng ◽  
Shaowei Zhang ◽  
...  

2017 ◽  
Vol 101 (3) ◽  
pp. 1036-1041 ◽  
Author(s):  
Acacio Rincón Romero ◽  
Hamada Elsayed ◽  
Enrico Bernardo

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Achille Gazzerro ◽  
Wilma Polini ◽  
Luca Sorrentino

Purpose Selective laser sintering (SLS) has passed other techniques, thanks to its high print resolution, its ability to print microscale geometries without any additional support, its surface quality and its long-term thermal stability. However, despite the many advantages of SLS compared to fusion deposition modelling, there are still today some limitations on the materials to be printed. A limit critical from an industrial point of view is the aging of PA12 powder, i.e. the degradation of its physical and chemical performances, due to the high temperatures and the long printing cycles, thus involving a decrease of the mechanical properties of the printed parts. The purpose of this study was to charaterize mechanically and dimensionally specimens printed in PA12 through SLS by means of virgin or aged powder, i.e. powder just used for five printing cycles. Design/methodology/approach To achieve this aim, a set of specimens were designed, built, measured and mechanically tested; the obtained results were put into relationship with the values of the process parameters used to print them. Statistical tools to design the experiments and to analyse the obtained results were used. Findings The results show that the SLS process carried out through a Sintratec machine on PA12 powder has a good repeatability. To obtain the best dimensional and mechanical performances, it is needed to use virgin powder and place the part in the central zone of the printing area. Originality/value There are no scientific articles dealing with the influence of both the aging of the powder and the manufacturing parameters on the dimensional and mechanical characterization of specimens printed with SLS technique in PA12.


ChemPlusChem ◽  
2019 ◽  
Vol 84 (2) ◽  
pp. 222-225 ◽  
Author(s):  
Elmeri Lahtinen ◽  
Rafaella L. M. Precker ◽  
Manu Lahtinen ◽  
Evamarie Hey-Hawkins ◽  
Matti Haukka

2014 ◽  
Vol 29 (11) ◽  
pp. 1179 ◽  
Author(s):  
LUO Xue-Wei ◽  
LI Hai-Feng ◽  
XIANG Wu-Guo ◽  
YUAN Hui ◽  
CHENG Cheng ◽  
...  

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