Ductile Phase Toughening of MoSi2-Chemical Compatibility and Fracture Toughness

1990 ◽  
Vol 194 ◽  
Author(s):  
L. Xiao ◽  
Y. S. Kim ◽  
Reza Abbaschian
Keyword(s):  
Fracture Toughness ◽  
Reinforced Composites ◽  
Matrix Interface ◽  
Chemical Compatibility ◽  
Interaction Zone ◽  
Ductile Phase ◽  
Reinforced Composite ◽  
The Matrix ◽  
Mullite Coatings ◽  
Bonding Characteristics

AbstractChemical compatibility between oxide coated Nb filament reinforcements and MoSi2 was investigated. It was determined that ZrO2, Al2O3, and mullite coatings were chemically compatible with both Nb and MoSi2. Comparison between coated and uncoated filaments indicated that the coatings reduced the thickness of the interaction zone. The fracture toughness of the Nb filament reinforced composites showed an increase, while W filament reinforced composite showed a decrease, in the toughness compared to that of the matrix. The results are discussed in terms of the mismatches in the coefficients of thermal expansion and the bonding characteristics of the reinforcement/matrix interface.

scholarly journals Efficient Improvement in Fracture Toughness of Laminated Composite by Interleaving Functionalized Nanofibers

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2509
Author(s):  
Seyed Mohammad Javad Razavi ◽  
Rasoul Esmaeely Neisiany ◽  
Moe Razavi ◽  
Afsaneh Fakhar ◽  
Vigneshwaran Shanmugam ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Fracture Behavior ◽  
Laminated Composite ◽  
Carbon Phase ◽  
Reinforced Composite ◽  
Reinforcing Agent ◽  
The Matrix ◽  
As Stress ◽  
Double Cantilever Beam Test ◽  
Pan Nanofiber

Functionalized polyacrylonitrile (PAN) nanofibers were used in the present investigation to enhance the fracture behavior of carbon epoxy composite in order to prevent delamination if any crack propagates in the resin rich area. The main intent of this investigation was to analyze the efficiency of PAN nanofiber as a reinforcing agent for the carbon fiber-based epoxy structural composite. The composites were fabricated with stacked unidirectional carbon fibers and the PAN powder was functionalized with glycidyl methacrylate (GMA) and then used as reinforcement. The fabricated composites’ fracture behavior was analyzed through a double cantilever beam test and the energy release rate of the composites was investigated. The neat PAN and functionalized PAN-reinforced samples had an 18% and a 50% increase in fracture energy, respectively, compared to the control composite. In addition, the samples reinforced with functionalized PAN nanofibers had 27% higher interlaminar strength compared to neat PAN-reinforced composite, implying more efficient stress transformation as well as stress distribution from the matrix phase (resin-rich area) to the reinforcement phase (carbon/phase) of the composites. The enhancement of fracture toughness provides an opportunity to alleviate the prevalent issues in laminated composites for structural operations and facilitate their adoption in industries for critical applications.

Fibre-Matrix Interface Development during High Temperature Exposition of Long Fibre Reinforced SiOC Matrix

2013 ◽  
Vol 592-593 ◽  
pp. 401-404
Author(s):  
Zdeněk Chlup ◽  
Martin Černý ◽  
Adam Strachota ◽  
Martina Halasova ◽  
Ivo Dlouhý
Keyword(s):  
High Temperature ◽  
Crack Formation ◽  
Fracture Behaviour ◽  
Point Of View ◽  
Reinforced Composites ◽  
Matrix Interface ◽  
Significant Damage ◽  
The Matrix ◽  
Fibre Matrix ◽  
Fibre Reinforced Composites

The fracture behaviour of long fibre reinforced composites is predetermined mainly by properties of fibre-matrix interface. The matrix prepared by pyrolysis of polysiloxane resin possesses ability to resist high temperatures without significant damage under oxidising atmosphere. The application is therefore limited by fibres and possible changes in the fibre matrix interface. The study of development of interface during high temperature exposition is the main aim of this contribution. Application of various techniques as FIB, GIS, TEM, XRD allowed to monitor microstructural changes in the interface of selected places without additional damage caused by preparation. Additionally, it was possible to obtain information about damage, the crack formation, caused by the heat treatment from the fracture mechanics point of view.

A Study of the Fiber-Matrix Interface in Composite Materials

1992 ◽  
Vol 59 (2S) ◽  
pp. S163-S165 ◽  
Author(s):  
Jin O. Kim ◽  
Haim H. Bau
Keyword(s):  
Composite Materials ◽  
Experimental Technique ◽  
Stress Waves ◽  
Matrix Interface ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
The Matrix ◽  
Fiber Matrix Interface ◽  
Dispersion And Attenuation

A novel experimental technique for studying the characteristics of the interface between the fibers and the matrix in both undamaged and damaged fiber-reinforced composite materials is described. The experimental technique involves the transmission of stress waves in one or more fibers of the composite. The characteristics of the stress waves, such as speed, dispersion, and attenuation, are measured. These measured variables can be correlated with the characteristics of the bonding between the fiber and the matrix.

scholarly journals Multiscale Characterization of Nanoengineered Fiber-Reinforced Composites: Effect of Carbon Nanotubes on the Out-of-Plane Mechanical Behavior

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Carlos Medina ◽  
Eduardo Fernandez ◽  
Alexis Salas ◽  
Fernando Naya ◽  
Jon Molina-Aldereguía ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Fracture Toughness ◽  
Shear Strength ◽  
Mechanical Behavior ◽  
Matrix Interface ◽  
Short Beam ◽  
The Matrix ◽  
Fiber Matrix Interface ◽  
Fiber Matrix

The mechanical properties of the matrix and the fiber/matrix interface have a relevant influence over the mechanical properties of a composite. In this work, a glass fiber-reinforced composite is manufactured using a carbon nanotubes (CNTs) doped epoxy matrix. The influence of the CNTs on the material mechanical behavior is evaluated on the resin, on the fiber/matrix interface, and on the composite. On resin, the incorporation of CNTs increased the hardness by 6% and decreased the fracture toughness by 17%. On the fiber/matrix interface, the interfacial shear strength (IFSS) increased by 22% for the nanoengineered composite (nFRC). The influence of the CNTs on the composite behavior was evaluated by through-thickness compression, short beam flexural, and intraply fracture tests. The compressive strength increased by 6% for the nFRC, attributed to the rise of the matrix hardness and the fiber/matrix IFSS. In contrast, the interlaminar shear strength (ILSS) obtained from the short beam tests was reduced by 8% for the nFRC; this is attributed to the detriment of the matrix fracture toughness. The intraply fracture test showed no significant influence of the CNTs on the fracture energy; however, the failure mode changed from brittle to ductile in the presence of the CNTs.

Ductile Phase Toughening of MoSi2: Effect of Reinforcement Morphology

1994 ◽  
Vol 350 ◽  
Author(s):  
Long-Ching Chen ◽  
Nedhal Bahtishi ◽  
Richard Lederich ◽  
Wolé Soboyejo
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Reinforced Composites ◽  
Ductile Phase ◽  
Reinforced Composite ◽  
Fine Fiber ◽  
Ductile Brittle Transition Temperature ◽  
Particulate Reinforced Composites ◽  
Particulate Reinforced

AbstractThe effects of ductile reinforcement morphology on the mechanical behavior of MoSi2 reinforced with 20 vol.% Nb are presented. While all the composites exhibit improved fracture toughness relative to the monolithic MoSi2, the most significant improvement is obtained in the composite with laminate reinforcement, followed by coarse fiber, fine fiber and particulate reinforcements. Bend strength measurements indicate a ductile-brittle-transition-temperature of ∼1250°C, and highlight the attractive properties of laminate reinforced composite. Preliminary studies of room temperature fatigue crack growth in particulate reinforced composites show a stable fatigue crack growth, which is not achieved in monolithic MoSi2. Possible ways of achieving a better combination of mechanical properties are also discussed.

Influence of multi-wall carbon nanotube content on dry and corrosive wear performances of pure magnesium

2018 ◽  
Vol 52 (23) ◽  
pp. 3127-3135 ◽  
Author(s):  
Muhammet E Turan ◽  
Yavuz Sun ◽  
Fatih Aydın ◽  
Yasin Akgul
Keyword(s):  
Carbon Nanotube ◽  
Hardness Test ◽  
Corrosive Wear ◽  
Pure Magnesium ◽  
Reinforced Composites ◽  
Wear Performance ◽  
Reinforced Composite ◽  
The Matrix ◽  
Corrosive Environments ◽  
Multi Wall Carbon Nanotube

The present study aims to investigate the effect of Multi-Wall Carbon Nanotube on dry sliding and corrosive wear performance of pure magnesium. Multi-wall carbon nanotube reinforced composites with different weight fractions (0.25 wt.% and 0.5 wt.%) were fabricated by semi powder metallurgy. Hardness test was performed for all samples. To evaluate wear performance of the samples, three different loads (10 N, 20 N, and 40 N) were applied at the room temperature in both dry and 3.5 wt.% NaCl corrosive environments. Worn surfaces and microstructures of the samples were characterized using Scanning Electron Microscope. Results show that carbon nanotubes embedded in the matrix without any macro-defects. The hardness of pure magnesium was improved with the addition of multi-wall carbon nanotube considerably. 0.5 wt.% multi-wall carbon nanotube reinforced composite exhibited best wear performance both in dry and corrosive conditions.

Effect of Ductile Phase Reinforcement Morphology on Toughening of MoSi2

1992 ◽  
Vol 273 ◽  
Author(s):  
D. E. Alman ◽  
N. S. Stoloff
Keyword(s):  
Room Temperature ◽  
Matrix Interface ◽  
Short Fibers ◽  
Ductile Phase ◽  
Aligned Fibers ◽  
The Matrix ◽  
Fiber Deformation ◽  
Bend Tests ◽  
Fiber Matrix Interface ◽  
Point Bend

ABSTRACTNiobium was added to MoSi2 in the form of particles, random short fibers and continuous aligned fibers. It was found that the morphology of Nb played a role in the toughening that occurred (as measured by the area under load displacement curves from room temperature three point bend tests and the examination of fracture surfaces). The Nb particles did not toughen MoSi2. The random short fibers appeared to toughen MoSi2 via crack deflection along the fiber matrix interface. Aligned fibers imparted the greatest toughness improvements, as toughening resulted from fiber deformation. However, larger diameter fibers displayed a greater ability to toughen MoSi2 than smaller diameter fibers. This was attributed to the constraint resulting from the interfacial layer between the MoSi2 matrix and the Nb fiber. Maximum toughness occurs when the fiber is able to separate from the matrix and freely deform.

scholarly journals Effect of Frictional Slipping on the Strength of Ribbon-Reinforced Composite

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4928
Author(s):  
Yosyf Piskozub ◽  
Heorhiy Sulym
Keyword(s):  
Dry Friction ◽  
Strain State ◽  
Complete System ◽  
Thin Inclusion ◽  
Matrix Interface ◽  
Reinforced Composite ◽  
The Matrix ◽  
Modular Method ◽  
Inclusion Matrix

A numerical–analytical approach to the problem of determining the stress–strain state of bimaterial structures with interphase ribbon-like deformable inhomogeneities under combined force and dislocation loading has been proposed. The possibility of delamination along a part of the interface between the inclusion and the matrix, where sliding with dry friction occurs, is envisaged. A structurally modular method of jump functions is constructed to solve the problems arising when nonlinear geometrical or physical properties of a thin inclusion are taken into account. A complete system of equations is constructed to determine the unknowns of the problem. The condition for the appearance of slip zones at the inclusion–matrix interface is formulated. A convergent iterative algorithm for analytical and numerical determination of the friction-slip zones is developed. The influence of loading parameters and the friction coefficient on the development of these zones is investigated.

scholarly journals Study on the Relationships between Microscopic Cross-Linked Network Structure and Properties of Cyanate Ester Self-Reinforced Composites

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 950
Author(s):  
Hongtao Cao ◽  
Beijun Liu ◽  
Yiwen Ye ◽  
Yunfang Liu ◽  
Peng Li
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
The Self ◽  
Reinforced Composites ◽  
Two Phase ◽  
Reinforced Composite ◽  
Transmission Electron ◽  
The Matrix ◽  
Ft Ir ◽  
The Cross

Bisphenol A dicyanate (BADCy) resin microparticles were prepared by precipitation polymerization synthesis and were homogeneously dispersed in a BADCy prepolymer matrix to prepare a BADCy self-reinforced composites. The active functional groups of the BADCy resin microparticles were characterized by Fourier transform infrared (FT-IR) spectroscopy. The results of an FT-IR curve showed that the BADCy resin microparticles had a triazine ring functional group and also had an active reactive group -OCN, which can initiate a reaction with the matrix. The structure of the BADCy resin microparticles was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). From the TEM results, the BADCy resin microparticles dispersed in the solvent were nano-sized and distributed at 40–60 nm. However, from the SEM results, agglomeration occurred after drying, the BADCy resin particels were micron-sized and distributed between 0.3 μm and 0.6 μm. The BADCy resin prepolymer was synthesized in our laboratory. A BADCy self-reinforced composite was prepared by using BADCy resin microparticles as a reinforcement phase. This corresponds to a composite in which the matrix and reinforcement phase are made from different morphologies of the same monomer. The DSC curve showed that the heat flow of the microparticles is different from the matrix during the curing reaction, this means the cured materials should be a microscopic two-phase structure. The added BADCy resin microparticles as reaction sites induced the formation of a more complete and regular cured polymer structure, optimizing the cross-linked network as well as increasing the interplay between the BADCy resin microparticles and prepolymer matrix. Relative to the neat BADCy resin material, the tensile strength, flexural strength, compressive strength and impact strength increased by 98.1%, 40.2%, 27.4%, and 85.4%, respectively. A particle toughening mechanism can be used to explain the improvement of toughness. The reduction in the dielectric constant showed that the cross-linked network of the self-reinforced composite was more symmetrical and less polar than the neat resin material, which supports the enhanced mechanical properties of the self-reinforced composite. In addition, the thermal behavior of the self-reinforced composite was characterized by thermogravimetric analysis (TGA) and dynamic mechanical thermal analysis (DMTA). The results of DMTA also establishes a basis for enhancing mechanical properties of the self-reinforced composite.

scholarly journals Synthesis, physico-mechanical and microstructural characterization of Al6063/SiC/PKSA hybrid reinforced composites

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
P. P. Ikubanni ◽  
M. Oki ◽  
A. A. Adeleke ◽  
P. O. Omoniyi
Keyword(s):  
Fracture Toughness ◽  
Hybrid Composites ◽  
Palm Kernel ◽  
Reinforced Composites ◽  
Sem Images ◽  
X Ray ◽  
Casting Technique ◽  
Palm Kernel Shell ◽  
The Matrix ◽  
Agro Residues

AbstractThe utilization of agro-residues ash as complementary reinforcing materials continues to gain prominence for metal matrix composite (MMCs) development. A rarely investigated but largely available ash among these agro-residues is the palm kernel shell ash (PKSA). Thus, the present study investigates the influence of PKSA particulates hybridized with SiC on the physico-mechanical properties and microstructure of Al6063 metal composites. The composites are synthesized using the double stir-casting technique with SiC held constant at 2 wt.%, while the PKSA contents are varied from 0 to 8 wt.%. The phases present and morphology of the composites are investigated using X-ray diffractometer (XRD) and scanning electron microscopy (SEM), respectively. The density, porosity, hardness, tensile and fracture toughness tests are carried out on the hybrid composites. X-ray diffractometer revealed that for Al 6063, only Al cubic crystal system was identifiable within the matrix. However, for the reinforced composites, major phases identified are Al, Fe3Si, SiC, MgO, and SiO2. The SEM images show that the particulates reinforcements (SiC and PKSA) were uniformly dispersed in the matrix. The percentage porosity for the composites ranged from 2.06 to 2.39%. In addition, hardness, yield strength and ultimate tensile strength of the composites are about 10.3%, 18.5% and 10.4%, respectively better than for Al 6063. However, the percent elongation and fracture toughness are lower for the hybrid composites than for Al 6063 and SiC reinforced composite with values decreasing with increase in ash content. Hence, the MMCs produced will be applicable for light-weight engineering applications.

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