Characterization of mixture epoxy syntactic foams highly loaded with thermoplastic and glass microballoons

2018 ◽  
Vol 53 (13) ◽  
pp. 1737-1749 ◽  
Author(s):  
Kerrick R Dando ◽  
William M Cross ◽  
Marc J Robinson ◽  
David R Salem
Keyword(s):  
Volume Fraction ◽  
High Volume ◽  
Mechanical And Thermal Properties ◽  
Syntactic Foams ◽  
Micro Computed Tomography ◽  
Quantitative Characterization ◽  
Aerospace Applications ◽  
Non Destructive ◽  
Peak Impact Force

Syntactic foams comprising glass or thermoplastic microballoons have gained considerable attention in recent years due to mechanical and thermal properties that are advantageous for naval and aerospace applications. This work reports a method for producing syntactic foams with unusually high-volume fraction microballoon loadings (>0.74) and its utilization for the creation of “hybrid” epoxy resin-based syntactic foams comprising various mixtures of glass and thermoplastic microballoons. Microstructural analyses using X-ray micro-computed tomography provided non-destructive quantitative characterization of microballoon packing, confirming the high loading levels suggested by density measurements. By systematically varying the glass/thermoplastic microballoon ratio, it was shown that a range of mechanical properties can be engineered into these lightweight materials. The peak impact force of these syntactic foams can be significantly reduced (∼30% reduction) through combining glass and thermoplastic microballoons in a ratio where the thermoplastic microballoons are the dominant fraction but not the sole microballoon component.

The effect of nano-additive reinforcements on thermoplastic microballoon epoxy syntactic foam mechanical properties

2017 ◽  
Vol 52 (7) ◽  
pp. 971-980 ◽  
Author(s):  
Kerrick R Dando ◽  
David R Salem
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanofiber ◽  
Volume Fraction ◽  
Syntactic Foam ◽  
Halloysite Nanotubes ◽  
Core Material ◽  
Mechanical And Thermal Properties ◽  
Syntactic Foams ◽  
Micro Computed Tomography ◽  
Halloysite Nanotube

Syntactic foams comprising glass microballoons have gained considerable attention over the past several years due to mechanical and thermal properties that are advantageous for use as a core material in naval and aerospace applications. Recent advancements in the production of thermoplastic microballoon syntactic foams have allowed for an increase in microballoon volume fraction (up to 0.9 volume fraction), with correspondingly lower densities but reduced mechanical properties. In this work, carbon nanofibers and halloysite nanotubes were incorporated in thermoplastic microballoon-based syntactic foam to enhance the mechanical properties and the relative effects of these two nanoscale reinforcements were compared. X-ray micro-computed tomography was employed to analyze the microstructure of the materials produced, and scanning electron microscopy was used to assess the dispersion of nano-additives within the resin. Compressive strength and modulus enhancements as large as 180% and 250% respectively were achieved with a 0.25 wt% addition of carbon nanofiber and increases of 165% and 244% respectively were achieved with a 0.5 wt% addition of halloysite nanotube. Tensile strength and modulus enhancements as large as 110% and 165% respectively were achieved with a 0.125 wt% addition of carbon nanofiber and increases of 133% and 173% respectively were achieved with a 0.125 wt% addition of halloysite nanotube.

scholarly journals Structural Characterization of Hexagonal Braiding Architecture Aided by 3D Printing

2018 ◽  
Vol 153 ◽  
pp. 08004
Author(s):  
Zhengning Li ◽  
Ge Chen ◽  
Haichen Lyu ◽  
Chenwang Yuan ◽  
Frank Ko
Keyword(s):  
3D Printing ◽  
Structural Characterization ◽  
Geometric Structure ◽  
Volume Fraction ◽  
High Volume ◽  
High Volume Fraction ◽  
Hexagonal Prism ◽  
Geometry Structure ◽  
Unit Cells

Hexagonal braiding method has the advantages of high shape compatibility, interlacing density and high volume fraction. Based on hexagonal braiding method, a hexagonal preform was braided. Then, by following the characteristics of repeatability and concentricity of hexagonal braided preform, the printed geometry structure was got in order to understand and optimize geometric structure to make it more compact like the braided geometric structure. Finally, the unit cells were defined with hexagonal prism to analyze the micro-geometric structure of hexagonal braided preform.

Defect Detection of Metal Injection Modeling by Micro Computed Tomography

2012 ◽  
Vol 229-231 ◽  
pp. 1445-1448
Author(s):  
Wei Yun Huang ◽  
Chang Da Chen ◽  
Yen Nien Chen ◽  
Wei Jen Shih ◽  
Chih Han Chang
Keyword(s):  
Computed Tomography ◽  
Injection Molding ◽  
Hot Isostatic Pressing ◽  
Cost Effective ◽  
High Volume ◽  
Metal Injection Molding ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Destructive Testing ◽  
Non Destructive

Metal injection molding (MIM) is a combination of metal powder and injection molding technology. The main advantage of this technology for material parts with small and complex shape is to manufacture cost-effective and high-volume products. The main processing steps include mixing, injection molding, debinding , sintering, and hot isostatic pressing (HIP) in order to reduce internal porosity of metals, then to improve mechanical properties. This study is based on non-destructive testing method to determine the possible defect inside the internal structure of the MIM parts. Three types of parts with and without HIP were evaluated investigated in this study. The micro computed tomography (Micro-CT) is used to scan these parts. Based the reconstructed section images from CT, the defects can be identified. It showed that with HIP the much of detects could be reduced. To conclude, Micro CT could be used to detect, in a non-destructive way, the internal detect within MIM parts can be found out in the micro-CT images, so that the manufacturing process could be modified to improve the quality of MIM parts.

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