scholarly journals Unidirectional fibre reinforced geopolymer matrix composites

2021 ◽  
Author(s):  
◽  
Michael Welter
Keyword(s):  
Room Temperature ◽  
Matrix Composition ◽  
Flexural Properties ◽  
Matrix Composites ◽  
Basalt Fibre ◽  
Geopolymer Matrix ◽  
Fibre Composites ◽  
The Matrix ◽  
Carbon Fibre Composites ◽  
Unidirectional Fibre

<p>Geopolymers have been suggested in the literature as matrix materials for fibre reinforced composites due to a unique combination of low-temperature synthesis and high temperature stability. This study investigated several key aspects of fibre reinforced geopolymer matrix composites in order to improve the basic knowledge of these materials. It was demonstrated that geopolymer matrix composites show great potential as fire-resistant materials for near room temperature applications. In particular, basalt fibre composites were of great interest due to their comparatively low cost and good mechanical performance. Microstructural investigations indicated that basalt fibres can potentially be used in geopolymer matrices up to 600°C. However, the success of the application of geopolymer matrix composites at higher temperatures is seen as critical and depends on further development of suitable matrices.  Several compositions within a sodium-metahalloysite model matrix system were evaluated in order to identify a suitable formulation for composite fabrication. An average compressive strength of ~ 79 MPa and flexural strength and modulus of ~ 10 MPa and 8.5 GPa, respectively, were achieved for the best batch of the main matrix composition. By optimising the matrix composition, the mechanical properties could be significantly improved, achieving an extremely high maximum compressive strength value of 145 MPa. Issues with reproducibility and the influence of various aspects of the fabrication process are discussed.  The room temperature flexural properties of unidirectional fibre reinforced composite bars with basalt, carbon and alumina fibres were investigated. Besides the fibre type, the effects of several other parameters including fibre sizing, matrix strength, span-to-depth ratio and specimen dimensions on the flexural properties and the failure behaviour of the composites were studied. Significant improvements to the mechanical properties were achieved with all fibre types. However, the mechanical behaviour was highly influenced by the elastic modulus of the fibre. Furthermore, it was shown that the composite properties were affected by the overall sample dimensions, the testing span and the mixing time of the geopolymer binder. The alumina fibre composites achieved the highest flexural stress with a maximum value of 470 MPa and a fibre content of ~ 30 vol.-%. Basalt and carbon fibre composites showed maximum flexural strength values around 200 MPa. Although all composite types displayed considerable post-fracture strength, only the basalt composites failed in tensile mode. The applicability of the weak matrix composites (WMC) concept to describe the mechanical behaviour of geopolymer matrix composites was discussed.  The fibre-matrix interactions were analysed between room temperature and 1000°C by means of electron microscopy, EDS and x-ray diffraction. All fibres were found to be chemically stable under the highly alkaline conditions of the geopolymer synthesis and showed no significant reaction with the geopolymer matrix at room temperature. The results indicate that basalt fibre composites may be used up to 600°C without significant degradation of the fibre. The heating of the carbon fibre composites to 600°C had drastic effect on the strength and integrity of the composite, in particular, when using sized carbon fibres. The alumina fibres showed good wetting and bonding behaviour but otherwise little reaction with the matrix even after heating to 1000°C.</p>

scholarly journals Unidirectional fibre reinforced geopolymer matrix composites

2021 ◽  
Author(s):  
◽  
Michael Welter
Keyword(s):  
Room Temperature ◽  
Matrix Composition ◽  
Flexural Properties ◽  
Matrix Composites ◽  
Basalt Fibre ◽  
Geopolymer Matrix ◽  
Fibre Composites ◽  
The Matrix ◽  
Carbon Fibre Composites ◽  
Unidirectional Fibre

<p>Geopolymers have been suggested in the literature as matrix materials for fibre reinforced composites due to a unique combination of low-temperature synthesis and high temperature stability. This study investigated several key aspects of fibre reinforced geopolymer matrix composites in order to improve the basic knowledge of these materials. It was demonstrated that geopolymer matrix composites show great potential as fire-resistant materials for near room temperature applications. In particular, basalt fibre composites were of great interest due to their comparatively low cost and good mechanical performance. Microstructural investigations indicated that basalt fibres can potentially be used in geopolymer matrices up to 600°C. However, the success of the application of geopolymer matrix composites at higher temperatures is seen as critical and depends on further development of suitable matrices.  Several compositions within a sodium-metahalloysite model matrix system were evaluated in order to identify a suitable formulation for composite fabrication. An average compressive strength of ~ 79 MPa and flexural strength and modulus of ~ 10 MPa and 8.5 GPa, respectively, were achieved for the best batch of the main matrix composition. By optimising the matrix composition, the mechanical properties could be significantly improved, achieving an extremely high maximum compressive strength value of 145 MPa. Issues with reproducibility and the influence of various aspects of the fabrication process are discussed.  The room temperature flexural properties of unidirectional fibre reinforced composite bars with basalt, carbon and alumina fibres were investigated. Besides the fibre type, the effects of several other parameters including fibre sizing, matrix strength, span-to-depth ratio and specimen dimensions on the flexural properties and the failure behaviour of the composites were studied. Significant improvements to the mechanical properties were achieved with all fibre types. However, the mechanical behaviour was highly influenced by the elastic modulus of the fibre. Furthermore, it was shown that the composite properties were affected by the overall sample dimensions, the testing span and the mixing time of the geopolymer binder. The alumina fibre composites achieved the highest flexural stress with a maximum value of 470 MPa and a fibre content of ~ 30 vol.-%. Basalt and carbon fibre composites showed maximum flexural strength values around 200 MPa. Although all composite types displayed considerable post-fracture strength, only the basalt composites failed in tensile mode. The applicability of the weak matrix composites (WMC) concept to describe the mechanical behaviour of geopolymer matrix composites was discussed.  The fibre-matrix interactions were analysed between room temperature and 1000°C by means of electron microscopy, EDS and x-ray diffraction. All fibres were found to be chemically stable under the highly alkaline conditions of the geopolymer synthesis and showed no significant reaction with the geopolymer matrix at room temperature. The results indicate that basalt fibre composites may be used up to 600°C without significant degradation of the fibre. The heating of the carbon fibre composites to 600°C had drastic effect on the strength and integrity of the composite, in particular, when using sized carbon fibres. The alumina fibres showed good wetting and bonding behaviour but otherwise little reaction with the matrix even after heating to 1000°C.</p>

Strength and Toughness of Composite Materials Based on Nickel Aluminide Matrices

1988 ◽  
Vol 133 ◽  
Author(s):  
J. D. Rigney ◽  
P. S. Khadkikar ◽  
J. J. Lewandowski ◽  
K. Vedula
Keyword(s):  
Fracture Toughness ◽  
Composite Materials ◽  
Hot Pressing ◽  
Nickel Aluminide ◽  
Room Temperature ◽  
Matrix Composition ◽  
Matrix Composites ◽  
The Matrix ◽  
Bend Tests

ABSTRACTSeveral nickel aluminide matrix composites were prepared using vacuum hot pressing techniques. The matrix compositions, based on Ni3Al, Ni3Al+B and NiAl, were reinforced with 10 volume % TiB2 particles. Both smooth and notched bend tests were conducted at room temperature on the monolithic as well as the reinforced materials in order to determine the effects of TiB2 reinforcement on both the smooth bend and notched bend properties. TiB2 additions were shown to improve the smooth bend strengths regardless of the matrix composition while notched bend tests, conducted to provide estimates of fracture toughness, revealed somewhat lower values for the composites in comparison to the monolithic materials. Fractographic analyses and in-situ fracture observations of the composites revealed that preferential fracture in regions of clustered TiB2 particles may significantly affect the measured toughnesses.

scholarly journals Composites Base on Geopolymer Matrices: Preliminary Fabrication, Mechanical Properties and Future Applications

2008 ◽  
Vol 55-57 ◽  
pp. 477-480 ◽  
Author(s):  
T.D. Hung ◽  
D. Pernica ◽  
Dora Kroisová ◽  
Oleg Bortnovsky ◽  
Petr Louda ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Structure Characterization ◽  
Alkali Resistance ◽  
Matrix Composites ◽  
Japanese Industrial Standard ◽  
Geopolymer Matrix ◽  
The Matrix ◽  
Fiber Reinforcements ◽  
Geopolymer Composites

Geopolymer matrice Composites are fabricated at room temperature or thermoset in a simple autoclave. After approximately four hours of curing, composite materials exhibit excellent properties. Finding applications of geopolymeric composites in all fields of industry are the hot topics. This paper covers: (i) mechanical properties of fibers: carbon, Saint-Gobain Cemfil/CFV alkali resistance glass (various types), ARG-NEC (Nippon electric Columbia) alkali resistance glass, E-glass for pultrusion, AR glass for pultrusion were evaluated in accordance with Japanese Industrial Standard (JIS R 7601). (ii) properties of geopolymeric matrices: geopolymeric matrices are fabricated from various types of geopolymeric resins that were made at Research Institute of Inorganic Chemistry, Inc., Czech Republic and testing for mechanical properties, and by SEM for structure characterization. (iii) fabrication procedures of geopolymer matrix composites with carbon and other fiber reinforcements. (iv) results of mechanical testing of geopolymer composites, SEM for adhesion between the matrix and reinforcement, and (v) Results and discussion.

scholarly journals Microstructure and Tensile Properties of Graphene-Oxide-Reinforced High-Temperature Titanium-Alloy-Matrix Composites

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3358 ◽  
Author(s):  
Hang Chen ◽  
Guangbao Mi ◽  
Peijie Li ◽  
Xu Huang ◽  
Chunxiao Cao
Keyword(s):  
Tensile Strength ◽  
Titanium Alloy ◽  
Graphene Oxide ◽  
High Temperature ◽  
Yield Strength ◽  
Room Temperature ◽  
Second Phase ◽  
Matrix Composites ◽  
Alloy Matrix ◽  
The Matrix

In this study, graphene-oxide (GO)-reinforced Ti–Al–Sn–Zr–Mo–Nb–Si high-temperature titanium-alloy-matrix composites were fabricated by powder metallurgy. The mixed powders with well-dispersed GO sheets were obtained by temperature-controlled solution mixing, in which GO sheets adsorb on the surface of titanium alloy particles. Vacuum deoxygenating was applied to remove the oxygen-containing groups in GO, in order to reduce the introduction of oxygen. The compact composites with refined equiaxed and lamellar α phase structures were prepared by hot isostatic pressing (HIP). The results show that in-situ TiC layers form on the surface of GO and GO promotes the precipitation of hexagonal (TiZr)6Si3 particles. The composites exhibit significant improvement in strength and microhardness. The room-temperature tensile strength, yield strength and microhardness of the composite added with 0.3 wt% GO are 9%, 15% and 27% higher than the matrix titanium alloy without GO, respectively, and the tensile strength and yield strength at 600 °C are 3% and 21% higher than the matrix alloy. The quantitative analysis indicates that the main strengthening mechanisms are load transfer strengthening, grain refinement and (TiZr)6Si3 second phase strengthening, which accounted for 48%, 30% and 16% of the improvement of room-temperature yield strength, respectively.

Investigation of NiAl–TiB2in situcomposites

1997 ◽  
Vol 12 (4) ◽  
pp. 1083-1090 ◽  
Author(s):  
J. T. Guo ◽  
Z. P. Xing
Keyword(s):  
Fracture Toughness ◽  
Yield Strength ◽  
Hot Pressing ◽  
Room Temperature ◽  
Tensile Yield Strength ◽  
Matrix Composites ◽  
Orientation Relationships ◽  
The Matrix ◽  
Atomically Flat ◽  
Nial Matrix

A hot-pressing aided exothermic synthesis (HPES) technique to fabricate NiAl matrix composites containing 0 and 20 vol.% TiB2 particles was developed. The conversion of mixtures of elements to the product was complete after processing, and TiB2 particles in the matrix were uniformly dispersed. The microstructure and interfaces were very thermally stable. The interfaces between NiAl and TiB2 were atomically flat, sharp, and generally free from interfacial phases. In some cases, however, thin amorphous layers existed at NiAl/TiB2 interfaces. At least three kinds of orientation relationships between TiB2 and NiAl were observed. The compressive yield strengths at room temperature and at 1000 °C of the composite were approximately three times as strong as those of the unreinforced NiAl. The tensile yield strength at 980 °C of the composite was about three times stronger than that of NiAl. The ambient fracture toughness of the composite was slightly greater than that of the monolithic NiAl.

A Review of the Status and Developmental Issues for Continuously-Reinforced Ti-Aluminide Composites for Structural Applications

1994 ◽  
Vol 350 ◽  
Author(s):  
D. B. Miracle ◽  
P. R. Smith ◽  
J. A. Graves
Keyword(s):  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Volume Fraction ◽  
Mechanical Load ◽  
Matrix Composition ◽  
Matrix Composites ◽  
Development Activity ◽  
Developmental Issues ◽  
Structural Applications ◽  
The Matrix

AbstractA significant materials-based activity to develop Ti-aluminide metal matrix composites for high temperature aerospace structural applications is now underway. A review of the approaches, progress, and status of the development of continuously-reinforced Ti-aluminide metal matrix composites with matrices which contain a significant volume fraction of the ordered orthorhombic Ti2AlNb phase will be presented. The principal application considered is a gas turbine compressor rotor ring, and this influences the development approaches and properties goals. Specific development activity that will be presented includes modification and control of the matrix composition and microstructure, fiber coating treatments to control interdiffusion between the fiber and the matrix, and to improve the ability of the interface to support a mechanical load, and efforts to improve the properties of SiC monofilaments used as reinforcements. Critical issues that define the requirements for additional studies will be presented.

scholarly journals COMPRESSIVE PROPERTIES OF GEOPOLYMER MATRIX COMPOSITES

2018 ◽  
Vol 179 ◽  
pp. 02003
Author(s):  
Robin Hron ◽  
František Martaus ◽  
Martin Kadlec
Keyword(s):  
Room Temperature ◽  
Aircraft Industry ◽  
Matrix Composites ◽  
Compressive Properties ◽  
Reinforced Composite ◽  
Geopolymer Matrix ◽  
Fire Smoke ◽  
New Type ◽  
Cost Efficient ◽  
The Impact

Polymer based resin is presently the most used resin for preparing of composites constructions, because of its undisputable benefits; however, there are some limits. The aircraft industry has especially strict requirements for fire, smoke and toxicity (FST) properties which are limited when using organic polymers. Conventional polymer resins resist to temperatures usually up to 120 °C and then they lose stiffness and strength. However, geopolymer matrix is a new type of resin with high potential for cost-efficient applications dealing with temperatures up to 1 200 °C. This paper presents compressive properties of a new geopolymer resin and a fibre reinforced composite with the geopolymer matrix (geocomposite). The effect of a harsh environment exposition on the strength was also evaluated, specifically the impact of the exposure in hot-wet and salt mist conditions. Samples were tested in accordance with ASTM D695 in case of pure resin and in accordance with ASTM D6641 in case of the geocomposite. All tests were performed at room temperature and additionally, pure geopolymer resin was tested at 400 °C. The high temperature caused 35 % decrease of the compressive strength in comparison with the room temperature. Geopolymers behaves like a ceramic and have some unique properties such as high thermal stability, non-flammability and do not generate toxic smoke and fumes.

Microstructure and Mechanical Bevavior of Ni3Al-Matrix Composites

1990 ◽  
Vol 194 ◽  
Author(s):  
P. C. Brennan ◽  
W. H. Kao ◽  
S. M. Jeng ◽  
J.-M. Yang
Keyword(s):  
Yield Strength ◽  
Nickel Aluminide ◽  
Fracture Stress ◽  
Room Temperature ◽  
Hot Extrusion ◽  
Matrix Composites ◽  
The Matrix ◽  
Bend Tests ◽  
Point Bend ◽  
Particulate Reinforced

AbstractAn aluminum oxide particulate-reinforced nickel-aluminide composite was fabricated by vacuum hot pressing and hot extrusion. Room temperature three point bend tests were conducted after 1 and 100 h at 1000 °C. The composite exhibited a decrease in yield strength from 772 to 517 MPa after 100 h while the ultimate fracture stress decreased from 1174 to 998 MPa. The strain to failure increased from 4.6% to 6.0% after the same exposure. Saphikon single crystal Al2O3 fibers were used to demonstrate the materials' compatibility. The fracture surfaces of the failed composites indicated ductile failures in the matrix and decohesion between the particles and matrix.

scholarly journals Residual stress variation in SiCf/SiC composite during heat treatment and its effects on mechanical behavior

2020 ◽  
Author(s):  
Xiaowu Chen ◽  
Guofeng Cheng ◽  
Junmin Zhang ◽  
Feiyu Guo ◽  
Haijun Zhou ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress Reduction ◽  
Tensile Strain ◽  
Room Temperature ◽  
Ceramic Matrix Composites ◽  
Matrix Composites ◽  
Stress Variation ◽  
Sic Fiber ◽  
The Matrix ◽  
Sic Composites

Abstract Residual stress originated from thermal expansion mismatch determines the mechanical properties of ceramic matrix composites (CMCs). Here, continuous SiC fiber reinforced SiC matrix (SiCf/SiC) composites were fabricated by nano-infiltration and transient eutectic-phase (NITE) method, and variation of residual stress in the constituent phases was investigated using high-temperature Raman spectrometer. With temperature increasing from room temperature to 1400°C, residual stresses of the matrix and the fiber decrease from 1.29 GPa to 0.62 GPa and from 0.84 GPa to 0.55 GPa in compression respectively, while that of the interphase decreases from 0.16 GPa to 0.10 GPa in tension. The variation of residual stress shows little effect in the tensile strength of the composites, while causes a slight decrease in the tensile strain. Suppression of fiber/matrix debonding and fiber pulling-out caused by the residual stress reduction in the interphase is responsible for the decreasing tensile strain. This work can open up new alternatives for residual stress analysis in CMCs.

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