scholarly journals Effects of SiC Fibers and Laminated Structure on Mechanical Properties of Ti–Al Laminated Composites

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1323
Author(s):  
Chenyang Hou ◽  
Shouyin Zhang ◽  
Zhijian Ma ◽  
Baiping Lu ◽  
Zhenjun Wang
Keyword(s):  
Volume Fraction ◽  
Raw Materials ◽  
Laminated Composites ◽  
Intermetallic Layer ◽  
Longitudinal Direction ◽  
Fracture Mechanisms ◽  
Compact Structure ◽  
Laminated Structure ◽  
Sic Fibers ◽  
Sic Fiber

Ti/Ti–Al and SiCf-reinforced Ti/Ti–Al laminated composites were fabricated through vacuum hot-pressure using pure Ti foils, pure Al foils and SiC fibers as raw materials. The effects of SiC fiber and a laminated structure on the properties of Ti–Al laminated composites were studied. A novel method of fiber weaving was implemented to arrange the SiC fibers, which can guarantee the equal spacing of the fibers without introducing other elements. Results showed that with a higher exerted pressure, a more compact structure with fewer Kirkendall holes can be obtained in SiCf-reinforced Ti/Ti–Al laminated composites. The tensile strength along the longitudinal direction of fibers was about 400 ± 10 MPa, which was 60% higher compared with the fabricated Ti/Ti–Al laminated composites with the same volume fraction (60%) of the Ti layer. An in situ tensile test was adopted to observe the deformation behavior and fracture mechanisms of the SiCf-reinforced Ti/Ti–Al laminated composites. Results showed that microcracks first occurred in the Ti–Al intermetallic layer.

TEM characterization of reaction zone in a SiC fiber-reinforced titanium alloy

1988 ◽  
Vol 46 ◽  
pp. 738-739
Author(s):  
G. Das ◽  
R. E. Omlor
Keyword(s):  
Titanium Alloys ◽  
Reaction Zone ◽  
Carbon Layer ◽  
Fiber Reinforced ◽  
Reaction Products ◽  
Sic Fibers ◽  
Sic Fiber ◽  
The Matrix ◽  
Immense Potential

Fiber reinforced titanium alloys hold immense potential for applications in the aerospace industry. However, chemical reaction between the fibers and the titanium alloys at fabrication temperatures leads to the formation of brittle reaction products which limits their development. In the present study, coated SiC fibers have been used to evaluate the effects of surface coating on the reaction zone in the SiC/IMI829 system.IMI829 (Ti-5.5A1-3.5Sn-3.0Zr-0.3Mo-1Nb-0.3Si), a near alpha alloy, in the form of PREP powder (-35 mesh), was used a茸 the matrix. CVD grown AVCO SCS-6 SiC fibers were used as discontinuous reinforcements. These fibers of 142μm diameter contained an overlayer with high Si/C ratio on top of an amorphous carbon layer, the thickness of the coating being ∽ 1μm. SCS-6 fibers, broken into ∽ 2mm lengths, were mixed with IMI829 powder (representing < 0.1vol%) and the mixture was consolidated by HIP'ing at 871°C/0. 28GPa/4h.

scholarly journals Mechanical properties, deformation and fracture mechanisms of bimodal Cu under tensile test

2021 ◽  
Vol 60 (1) ◽  
pp. 15-24
Author(s):  
Silu Liu ◽  
Yonghao Zhao
Keyword(s):  
Yield Strength ◽  
Grain Refinement ◽  
Volume Fraction ◽  
Shear Fracture ◽  
High Strength ◽  
Tensile Specimen ◽  
Deformation Mechanisms ◽  
Fracture Mechanisms ◽  
Fracture Angle ◽  
Area Reduction

Abstract Metals with a bimodal grain size distribution have been found to have both high strength and good ductility. However, the coordinated deformation mechanisms underneath the ultrafine-grains (UFGs) and coarse grains (CGs) still remain undiscovered yet. In present work, a bimodal Cu with 80% volume fraction of recrystallized micro-grains was prepared by the annealing of equal-channel angular pressing (ECAP) processed ultrafine grained Cu at 473 K for 40 min. The bimodal Cu has an optimal strength-ductility combination (yield strength of 220 MPa and ductility of 34%), a larger shear fracture angle of 83∘ and a larger area reduction of 78% compared with the as-ECAPed UFG Cu (yield strength of 410 MPa, ductility of 16%, shear fracture angle of 70∘, area reduction of 69%). Grain refinement of recrystallized micro-grains and detwinning of annealing growth twins were observed in the fractured bimodal Cu tensile specimen. The underlying deformation mechanisms for grain refinement and detwinning were analyzed and discussed.

scholarly journals Comparative study of elastic properties and mode I fracture energy of carbon nanotube/epoxy and carbon fibre/epoxy laminated composites

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Jyotikalpa Bora ◽  
Sushen Kirtania
Keyword(s):  
Carbon Nanotube ◽  
Carbon Fibre ◽  
Fracture Energy ◽  
Elastic Properties ◽  
Volume Fraction ◽  
Laminated Composites ◽  
Laminated Composite ◽  
Fe Analysis ◽  
Mode I ◽  
Mode I Fracture

Abstract A comparative study of elastic properties and mode I fracture energy has been presented between conventional carbon fibre (CF)/epoxy and advanced carbon nanotube (CNT)/epoxy laminated composite materials. The volume fraction of CNT fibres has been considered as 15%, 30%, and 60% whereas; the volume fraction of CF has been kept constant at 60%. Three stacking sequences of the laminates viz.[0/0/0/0], [0/90/0/90] and [0/30/–30/90] have been considered in the present analysis. Periodic microstructure model has been used to calculate the elastic properties of the laminated composites. It has been observed analytically that the addition of only 15% CNT in epoxy will give almost the same value of longitudinal Young’s modulus as compared to the addition of 60% CF in epoxy. Finite element (FE) analysis of double cantilever beam specimens made from laminated composite has also been performed. It has been observed from FE analysis that the addition of 15% CNT in epoxy will also give almost the same value of mode I fracture energy as compared to the addition of 60% CF in epoxy. The value of mode I fracture energy for [0/0/0/0] laminated composite is two times higher than the other two types of laminated composites.

scholarly journals Design of Low-Cost and High-Strength Titanium Alloys Using Pseudo-Spinodal Mechanism through Diffusion Couple Technology and CALPHAD

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2910
Author(s):  
Chaoyi Ding ◽  
Chun Liu ◽  
Ligang Zhang ◽  
Di Wu ◽  
Libin Liu
Keyword(s):  
Diffusion Couple ◽  
Titanium Alloys ◽  
High Throughput ◽  
Volume Fraction ◽  
Raw Materials ◽  
Low Cost ◽  
High Strength ◽  
High Yield ◽  
Α Phase ◽  
Cr System

The high cost of development and raw materials have been obstacles to the widespread use of titanium alloys. In the present study, the high-throughput experimental method of diffusion couple combined with CALPHAD calculation was used to design and prepare the low-cost and high-strength Ti-Al-Cr system titanium alloy. The results showed that ultra-fine α phase was obtained in Ti-6Al-10.9Cr alloy designed through the pseudo-spinodal mechanism, and it has a high yield strength of 1437 ± 7 MPa. Furthermore, application of the 3D strength model of Ti-6Al-xCr alloy showed that the strength of the alloy depended on the volume fraction and thickness of the α phase. The large number of α/β interfaces produced by ultra-fine α phase greatly improved the strength of the alloy but limited its ductility. Thus, we have demonstrated that the pseudo-spinodal mechanism combined with high-throughput diffusion couple technology and CALPHAD was an efficient method to design low-cost and high-strength titanium alloys.

Mesoscopic structure of SiC fibers by neutron and x-ray scattering

1996 ◽  
Vol 11 (5) ◽  
pp. 1169-1178 ◽  
Author(s):  
Kentaro Suzuya ◽  
Michihiro Furusaka ◽  
Noboru Watanabe ◽  
Makoto Osawa ◽  
Kiyohito Okamura ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Volume Fraction ◽  
X Rays ◽  
X Ray ◽  
Sic Fibers ◽  
X Ray Scattering ◽  
Mesoscopic Structure ◽  
Angle Scattering ◽  
Momentum Transfer Range ◽  
First Time

Mesoscopic structures of SiC fibers produced from polycarbosilane by different methods were studied by diffraction and small-angle scattering of neutrons and x-rays. Microvoids of a size of 4–10 Å in diameter have been observed for the first time by neutron scattering in a medium momentum transfer range (Q = 0.1–1.0 Å−1). The size and the volume fraction of β–SiC particles were determined for fibers prepared at different heat-treatment temperatures. The results show that wide-angle neutron scattering measurements are especially useful for the study of the mesoscopic structure of multicomponent materials.

Micro Palm and Kenaf Fibers Reinforced PLA Composite: Effect of Volume Fraction on Tensile Strength

2011 ◽  
Vol 145 ◽  
pp. 1-5 ◽  
Author(s):  
K.W. Neoh ◽  
Kim Yeow Tshai ◽  
P.S. Khiew ◽  
Chin Hua Chia
Keyword(s):  
Tensile Strength ◽  
Mechanical Stability ◽  
Volume Fraction ◽  
Environmental Concern ◽  
Raw Materials ◽  
Kenaf Fiber ◽  
Composite Effect ◽  
Fiber Loading ◽  
Biodegradable Composite ◽  
Kenaf Fibers

Extensive environmental concern associated with the disposal of solid plastic wastes has stirred tremendous interest in the production and use of sustainable biodegradable polymers. Among the vast variety of available materials, Polylactic Acid (PLA) standout as the most commercially viable mass produced resin to date. However, its low thermal and mechanical stability, excessive brittleness, and relatively higher cost have led to numerous research efforts in producing biodegradable polymer composite filled with natural organic fibers. This paper describes the preparation and the mechanical characteristics of a compression molded biodegradable composite made entirely of renewable raw materials. The composites were reinforced with pulverized palm, kenaf and alkali (1M NaOH:fiber in ratio 2:1) treated kenaf fibers, at a fiber mass proportion of 20 to 60% blended PLA and processed in a custom-built compression mold. SEM microscan revealed that the kenaf fiber has a mean diameter of 40μm, length 1236.6μm, and aspect ratio of 31 while the measured values for palm fiber was 58.7μm, 1041.2μm, and 17.7, respectively. All resulting composites showed significant enhancement in tensile strength. At 20, 40 and 60% fiber loading, the palm/PLA composite recorded tensile strength increment of 46.9, 47.8 and 36.6%, respectively. For the kenaf/PLA composite, greatest improvement was achieved at 40% fiber loading with alkali treated kenaf, with approximately 54% higher than the neat PLA while only 12.6% was recorded for the non-treated kenaf/PLA composite, signifying that the surface modification greatly improved fiber-matrix adhesion. SEM observations on the fracture surface showed similar findings. Compared to commercially available palm/Polypropylene (palm/PP) composite at 50% fiber loading, our measured tensile strength for the PLA composite loaded with 40% alkali treated kenaf fiber was still about 20% lower. Further enhancement in the mechanical characteristic of the kenaf/PLA composite is required to push for its wider utilization in the polymer industry.

The Effects of Fiber Volume Fraction on the Experiment Modal Behavior of 45°/-45° Carbon Fiber Plain Woven Fabric/Epoxy Resin Composites

2012 ◽  
Vol 583 ◽  
pp. 150-153
Author(s):  
Qian Liu ◽  
Xiao Yuan Pei ◽  
Jia Lu Li
Keyword(s):  
Carbon Fiber ◽  
Epoxy Resin ◽  
Natural Frequency ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Laminated Composites ◽  
Woven Fabric ◽  
Resin Composites ◽  
Fiber Volume ◽  
Epoxy Resin Composites

The modal properties of carbon fiber woven fabric (with fiber orientation of 45°/-45°) / epoxy resin composites with different fiber volume fraction were studied by using single input and single output free vibration of cantilever beam hammering modal analysis method. The effect of different fiber volume fraction on the modal parameters of laminated composites was analyzed. The experimental results show that with the fiber volume fraction increasing, the natural frequency of laminated composites becomes larger and damping ratio becomes smaller. The fiber volume fraction smaller, the peak value of natural frequency becomes lower and the attenuating degree of acceleration amplitude becomes faster.

A Yield Criterion of Porous Materials With Anisotropy Caused by Geometry or Distribution of Pores

1991 ◽  
Vol 113 (4) ◽  
pp. 425-429 ◽  
Author(s):  
T. Hisatsune ◽  
T. Tabata ◽  
S. Masaki
Keyword(s):  
Velocity Field ◽  
Porous Materials ◽  
Upper Bound ◽  
Volume Fraction ◽  
Yield Criterion ◽  
Longitudinal Direction ◽  
Axisymmetric Deformation ◽  
The Other ◽  
The Matrix ◽  
Spherical Cells

Axisymmetric deformation of anisotropic porous materials caused by geometry of pores or by distribution of pores is analyzed. Two models of the materials are proposed: one consists of spherical cells each of which has a concentric ellipsoidal pore; and the other consists of ellipsoidal cells each of which has a concentric spherical pore. The velocity field in the matrix is assumed and the upper bound approach is attempted. Yield criteria are expressed as ellipses on the σm σ3 plane which are longer in longitudinal direction with increasing anisotropy and smaller with increasing volume fraction of the pore. Furthermore, the axes rotate about the origin at an angle α from the σm-axis, while the axis for isotropic porous materials is on the σm-axis.

The Effect of Guide Sleeves on Shear Behavior of 3D Weaving Composites

2014 ◽  
Vol 597 ◽  
pp. 89-94 ◽  
Author(s):  
Xiao Chuan Wu ◽  
Zhong De Shan ◽  
Feng Liu ◽  
Yuan Wang
Keyword(s):  
Volume Fraction ◽  
Shear Behavior ◽  
Bending Test ◽  
Fracture Mechanisms ◽  
Study Guide ◽  
Fiber Layer ◽  
Resin Infusion ◽  
Interlaminar Shear ◽  
Shear Behaviors ◽  
3D Weaving

In this study, guide sleeves are brought into 3D weaving composite preforms. The process vacuum assisted resin infusion (VARI) was used to fabricate the 3D weaving composite with guide sleeves. The load-deflection curves and shear behaviors of the 3D weaving composites with guide sleeves were obtained by means of the 3-point bending test. The fracture micrographs of the materials were studied by SEM. The effects of guide sleeves’ diameter and interval on the shear behavior and fracture mechanisms of the 3D weaving composites were analyzed. The results showed that the guide sleeves could prevent delamination effectively by bridging fiber layer and pinning crack extending along the fiber layer. Fracture toughness of the composite parts increase because of deformation, fracture of guide sleeves and debonding of interface. The diameter and interval of guide sleeves is smaller, which means the volume fraction of guide sleeves is higher, the interlaminar shear strength higher for the bridging is stronger.

Mechanical properties of the tracheal mucosal membrane in the rabbit. II. Morphometric analysis

2000 ◽  
Vol 88 (3) ◽  
pp. 1022-1028 ◽  
Author(s):  
Lu Wang ◽  
Kenneth L. Pinder ◽  
Joel L. Bert ◽  
Mitsushi Okazawa ◽  
Peter D. Paré
Keyword(s):  
Mechanical Properties ◽  
Volume Fraction ◽  
Mechanical Load ◽  
Morphological Structure ◽  
Longitudinal Direction ◽  
Smooth Muscle Contraction ◽  
Elastic Fibers ◽  
Tissue Samples ◽  
Mucosal Membrane ◽  
Simple Geometry

Folding of the airway mucosal membrane provides a mechanical load that impedes airway smooth muscle contraction. Mechanical testing of rabbit tracheal mucosal membrane showed that the membrane is stiffer in the longitudinal than in the circumferential direction of the airway. To explain this difference in the mechanical properties, we studied the morphological structure of the rabbit tracheal mucosal membrane in both longitudinal and circumferential directions. The collagen fibers were found to form a random meshwork, which would not account for differences in stiffness in the longitudinal and circumferential directions. The volume fraction of the elastic fibers was measured using a point-counting technique. The orientation of the elastic fibers in the tissue samples was measured using a new method based on simple geometry and probability. The results showed that the volume fraction of the elastic fibers in the rabbit tracheal mucosal membrane was ∼5% and that the elastic fibers were mainly oriented in the longitudinal direction. Age had no statistically significant effect on either the volume fraction or the orientation of the elastic fibers. Linear correlations were found between the steady-state stiffness and the quantity of the elastic fibers oriented in the direction of testing.

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