Optimization of Degreasing-Sintering Process for Mg2Si/PLA Mixture and Influences of Additive Amount of Al on Sintered Density and Thermoelectric Performance of Mg2Si Fabricated by the Optimized Process

MRS Advances ◽  
2020 ◽  
Vol 5 (10) ◽  
pp. 459-467
Author(s):  
Takashi Itoh ◽  
Takumi Nakano
Keyword(s):  
3D Printing ◽  
Polymer Composite ◽  
Sintered Density ◽  
Solid Phase ◽  
Fused Deposition Modelling ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Sintering Process ◽  
Fused Deposition ◽  
Metal Polymer

ABSTRACTFused deposition modelling (FDM) type of 3D printing is widely used for manufacturing complex shaped polymer products. Recently, the metal/polymer composite products can be made by 3D printer using metal/polymer composite filament. Now, we are planning to develop a new manufacturing process of the thermoelectric (TE) elements or modules by combining the FDM-type 3D printing and the degreasing-sintering process. In this work, we focused on the degreasing-sintering process of the mixture of Mg2Si and polylactic acid (PLA) powders. Mg2Si compound powder was synthesized by a liquid-solid phase reaction (LSPR) method. The powder mixtures of Mg2Si, Al and PLA were pressed and heated in a pulse discharge sintering (PDS) chamber under a vacuum in various degreasing conditions. Following the degreasing, the sintering of Mg2Si was carried out in the same PDS chamber at various starting sintering temperatures. Sintered density, Seebeck coefficient and electrical resistivity of the consolidated Mg2Si were measured and the power factor as a TE performance was estimated from the TE properties. The optimum conditions of degreasing-sintering process maximizing the sintered density and the TE performance of Al-doped Mg2Si were investigated. Furthermore, the influences of the additive amount of Al on the sintered density and the TE performance of Mg2Si fabricated via the optimized degreasing-sintering process were investigated.

Thermal Conductivity Testing Apparatus for 3D Printed Materials

2017 ◽  
Author(s):  
Tiffaney Flaata ◽  
Gregory J. Michna ◽  
Todd Letcher
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Additive Manufacturing ◽  
3D Printing ◽  
Polymer Composite ◽  
Heat Exchangers ◽  
Fused Deposition ◽  
3D Printed ◽  
Printed Materials ◽  
Metal Polymer

Additive manufacturing, the layer-by-layer creation of parts, was initially used for rapid prototyping of new designs. Recently, due to the decrease in the cost and increase in the resolution and strength of additively manufactured parts, additive manufacturing is increasingly being used for production of parts for end-use applications. Fused Deposition Modeling (FDM), a type of 3d printing, is a process of additive manufacturing in which a molten thermoplastic material is extruded to create the desired geometry. Many potential heat transfer applications of 3d printed parts, including the development of additively manufactured heat exchangers, exist. In addition, the availability of metal/polymer composite filaments, first used for applications such as tooling for injection molding applications and to improve wear resistance, could lead to increased performance 3d printed heat exchangers because of the higher thermal conductivity of the material. However, the exploitation of 3d printing for heat transfer applications is hindered by a lack of reliable thermal conductivity data for as-printed materials, which typically include significant void fractions. In this experimental study, an apparatus to measure the effective thermal conductivity of 3d printed composite materials was designed and fabricated. Its ability to accurately measure the thermal conductivity of polymers was validated using a sample of acrylic, whose conductivity is well understood. Finally, the thermal conductivities of various 3d printed polymer, metal/polymer composite, and carbon/polymer composite filaments were measured and are reported in this paper. The materials used are acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), stainless steel/PLA, Brass/PLA, and Bronze/PLA.

Utilization of dried sludge for making ceramsite

2006 ◽  
Vol 54 (9) ◽  
pp. 69-79 ◽  
Author(s):  
G.R. Xu ◽  
J.L. Zou ◽  
Y. Dai
Keyword(s):  
Municipal Wastewater ◽  
Solid Phase ◽  
Particle Density ◽  
Raw Material ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Sintering Process ◽  
Sintering Time ◽  
Dried Sludge ◽  
Xrf Analyses

Dried sludge as additive for making ceramsite is a new effective approach for disposal of sludge. In this study sewage sludge, water glass and clay were chosen as the components, the optimal ratio of the components and the most appropriate conditions were obtained. The functions of primary components in the sintering process, porosity formation mechanism and solid phase reaction also have been discussed. The optimized process parameters were shown as follows: the ratio of dried sludge /clay (wt%) was 33%, ratio of adherent /clay (wt%) was 15%, sintering temperature was 1000 °C, sintering time was 10 min. Bulk density was 582 kg m−3, particle density was 1,033 kg m−3, water absorption was 9.5%, porosity was 43.7%. SEM, EDS, XRD and XRF analyses were also carried out. The results indicate that dried sludge as raw material is a good way for making ceramsite. Biological Aerated Filters (BAFs) with filter media of Guangzhou ceramsite, Jiangxi ceramsite, activated carbon and ceramsite (obtained in test) were selected to treat municipal wastewater. The average removal efficiencies of ceramsite (obtained in test) for turbidity, COD, SCOD and NH3-N were about 96.4%, 76.2%, 59.6% and 82.3% respectively and were higher than those of other ceramsites.

Dynamic Mechanical Thermal Properties of a New Metal/Polymer Composite for Fused Deposition Modelling Process

2007 ◽  
Vol 561-565 ◽  
pp. 795-798 ◽  
Author(s):  
W.Q. Song ◽  
Syed H. Masood
Keyword(s):  
Composite Material ◽  
Thermal Properties ◽  
Polymer Composite ◽  
Injection Moulding ◽  
Rapid Tooling ◽  
Fused Deposition Modelling ◽  
Mechanical And Thermal Properties ◽  
Dynamic Mechanical ◽  
Fused Deposition ◽  
Metal Polymer

This paper introduces an entirely new metal based composite material for direct rapid tooling application using Fused Deposition Modelling rapid prototyping system with desired mechanical and thermal properties and characteristics. The paper specifically describes the results of the dynamic mechanical thermal analysis (DMTA) of this new metal/polymer composite material, consisting of iron particles in nylon type matrix, for use in FDM process and with the aim of application to direct rapid tooling for injection moulding. The work represents a major development in the direction of direct rapid tooling for reducing the cost and time in tooling manufacture for injection moulding.

Preparation and Thermoelectric Properties of Bi Doped Ca3Co4O9 Based Thermoelectric Materials

2018 ◽  
Vol 783 ◽  
pp. 144-147
Author(s):  
Jing Wang ◽  
Qin Chen ◽  
Xia Chun Zhu ◽  
Seok Je Lee ◽  
Kyoung Woo Park ◽  
...  
Keyword(s):  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Phonon Scattering ◽  
Solid Phase ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Sintering Process ◽  
Spin Entropy ◽  
Plasma Sintering ◽  
Spark Plasma

Polycrystalline Ca3-xBixCo4O9 samples have been prepared by solid-phase reaction followed by spark plasma sintering process. The thermoelectric properties have been systematically investigated from room temperature to near 1000K. It is found that the change of the carrier concentration leads to the change of resistivity, which is mainly associated with doping induced point defect phonon scattering. The change of the thermal potential mainly comes from the spin entropy. In addition, polycrystalline Ca3-xBixCo4O9 had a maximum figure of merit of 0.30 at 973 K, which was about 50% higher than Ca3Co4O9. It indicated that doping approach can effectively improve the thermoelectric performance of Ca3Co4O9+δ-based material.

scholarly journals Fe3O4@C Nanoparticles Synthesized by In Situ Solid-Phase Method for Removal of Methylene Blue

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 330
Author(s):  
Hengli Xiang ◽  
Genkuan Ren ◽  
Yanjun Zhong ◽  
Dehua Xu ◽  
Zhiye Zhang ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Solid Phase ◽  
Raw Materials ◽  
Phase Method ◽  
Maximum Adsorption Capacity ◽  
High Catalytic Activity ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
High Concentrations

Fe3O4@C nanoparticles were prepared by an in situ, solid-phase reaction, without any precursor, using FeSO4, FeS2, and PVP K30 as raw materials. The nanoparticles were utilized to decolorize high concentrations methylene blue (MB). The results indicated that the maximum adsorption capacity of the Fe3O4@C nanoparticles was 18.52 mg/g, and that the adsorption process was exothermic. Additionally, by employing H2O2 as the initiator of a Fenton-like reaction, the removal efficiency of 100 mg/L MB reached ~99% with Fe3O4@C nanoparticles, while that of MB was only ~34% using pure Fe3O4 nanoparticles. The mechanism of H2O2 activated on the Fe3O4@C nanoparticles and the possible degradation pathways of MB are discussed. The Fe3O4@C nanoparticles retained high catalytic activity after five usage cycles. This work describes a facile method for producing Fe3O4@C nanoparticles with excellent catalytic reactivity, and therefore, represents a promising approach for the industrial production of Fe3O4@C nanoparticles for the treatment of high concentrations of dyes in wastewater.

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