A fractal model of tensile fracture surfaces for particulate‐filled polymer composites

The structure of the interlayer between matrix and inclusions affect directly the mechanical and physical properties of inorganic particulate-filled polymer composites. The interlayer thickness is an important parameter for characterization of the interfacial structure. The effects of the interlayer between the filler particles and matrix on the mechanical properties of polymer composites were analyzed in this article. On the basis of a simplified model of interlayer, an expression for estimating the interlayer thickness ([Formula: see text]) was proposed. In addition, the relationship between the [Formula: see text] and the particle size and its concentration was discussed. The results showed that the calculations of the [Formula: see text] and thickness/particle diameter ratio ([Formula: see text]) increased nonlinearly with an increase of the volume fraction of the inclusions. Moreover, the predictions of [Formula: see text] and the relevant data reported in literature were compared, and good agreement was found between them.

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Characterization of the fracture behaviour of X42 microalloyed pipeline steel

International Journal of Structural Integrity ◽

10.1108/ijsi-09-2013-0020 ◽

2015 ◽

Vol 6 (5) ◽

pp. 567-577

Author(s):

Halil Ibrahim Ünal ◽

Hakan Atapek ◽

Baran Gürkan Beleli ◽

Seyda Polat ◽

Serap Gümüs ◽

...

Keyword(s):

Fracture Behaviour ◽

Pipeline Steel ◽

Sheet Material ◽

Sheet Steel ◽

Grain Morphology ◽

Tensile Fracture ◽

Pipe Material ◽

Content Type ◽

Fracture Surfaces ◽

Impact Tests

Purpose – The purpose of this paper is to investigate the fracture of grade X42 microalloyed steel used as pipe material after tensile test at room temperature and impact tests at 0, −20 and −40°C, respectively. Design/methodology/approach – In the first stage of the study, X42 steels in the form of sheet and pipe materials were selected and etched samples were characterized using light microscope. In the second stage, mechanical properties of steels were obtained by microhardness measurements, static tensile and impact tests and all the broken surfaces were examined by scanning electron microscope to determine the fracture type as a function of both microstructure and loading. Findings – The examinations revealed that: first, the sheet material had a typical ferritic-pearlitic matrix, second, the transverse section of the sheet steel exhibited a matrix consisting of polygonal ferrite-aligned pearlite colonies and the longitudinal one had elongated ferrite phase and pearlite colonies in the direction of rolling, third, ferrite and pearlite distribution was different from the sheet material due to multiaxial deformation in the pipe material, fourth, tensile fracture surfaces of the steels had typical dimple fracture induced by microvoid coalescence, fifth, impact fracture surfaces of the steels changed as a function of the test temperature and cleavage fracture mode of ferritic-pearlitic matrix became more dominant as the temperature decreased, and sixth, grain morphology had an effect on the fracture behavior of the steels. Originality/value – The paper explains the fracture behaviour of X42 microalloyed pipeline steel and its fractographical analysis.

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Effect of graphite and silicon carbide fillers on mechanical properties of PA6 polymer composites

Journal of Polymer Engineering ◽

10.1515/polyeng-2015-0441 ◽

2017 ◽

Vol 37 (6) ◽

pp. 547-557 ◽

Cited By ~ 5

Author(s):

Sekaran Sathees Kumar ◽

Ganesan Kanagaraj

Keyword(s):

Mechanical Properties ◽

Silicon Carbide ◽

Polymer Composites ◽

Interfacial Adhesion ◽

Hybrid Composites ◽

Fracture Morphology ◽

Tensile Fracture ◽

Injection Molded ◽

The Individual

Abstract In this paper, the combined effect of different weight percentages of silicon carbide (SiC) and graphite (Gr) reinforcement on the mechanical properties of polyamide (PA6) composite is studied. Test specimens of pure PA6, 85 wt% PA6+10 wt% SiC+5 wt% Gr and 85 wt% PA6+5 wt% SiC+10 wt% Gr are prepared using an injection molding machine. The tensile, impact, hardness, morphology and thermal properties of the injection molded composites were investigated. The obtained results showed that mechanical properties, such as tensile and impact strength and modulus of the PA6 composites, were significantly higher than the pure PA6, and hybridization with silicon carbide and graphite further enhanced the performance properties, as well as the thermal resistance of the composites. The tensile fracture morphology and the characterization of PA6 polymer composites were observed by scanning electron microscope (SEM) and Fourier transform infrared spectroscopic methods. SEM observation of the fracture surfaces showed the fine dispersion of SiC and Gr for strong interfacial adhesion between fibers and matrix. The individual and combined reinforcing effects of silicon carbide and graphite on the mechanical properties of PA6 hybrid composites were compared and interpreted in this study. Improved mechanical properties were observed by the addition of small amount of SiC and Gr concurrently reinforced with the pure PA6. Finally, thermogravimetric analysis showed that the heat resistance of the composites tended to increase with increasing silicon carbide and graphite content simultaneously.

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Calculation on the Residual Stresses of Injection-Molded Conductive-Carbon-Fiber-Filled Polymer Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.629.55 ◽

2012 ◽

Vol 629 ◽

pp. 55-59

Author(s):

Ai Yun Jiang ◽

Jing Chao Zou ◽

Bao Feng Zhang ◽

Hai Hong Wu

Keyword(s):

Carbon Fiber ◽

Residual Stresses ◽

Polymer Composites ◽

Injection Molding Process ◽

Molding Process ◽

Filled Polymer ◽

The Core ◽

Packing Pressure ◽

Core Areas ◽

Injection Molded

For conductive-carbon-fiber-filled polymer composites, the residual stresses developed during injection molding process may affect not only the molding’s conductive property, but its dimensional stability as well. In order to improve the conductivity of the molding fabricated with this kind of composites, we investigated, using layer removal method, the distribution of the residual stresses of injection-molded conductive-carbon-fiber-filled polypropylene in this paper. The residual stresses were obtained under the actions of different processing conditions. Our results indicate that processing pressures have more significant effects on the residual stresses at the skin areas than the core areas of the sample because of fiber orientation. The tensile stresses of the molding at the core areas drop under the action of packing pressure, but the compressive stresses at the skin areas increase. The results reveal that the action of packing pressure may decrease the anisotropy of the residual stresses in the molding.

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