Study on the In Situ Growth of Carbon Nanotubes for the Reinforcement of Cf/SiC Composite Fabricated by CVI+PIP Process

2013 ◽  
Vol 745-746 ◽  
pp. 582-586 ◽  
Author(s):  
Jian Bao Hu ◽  
Shao Ming Dong ◽  
Xiang Yu Zhang ◽  
Zhen Wang ◽  
Hai Jun Zhou ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Bonding Strength ◽  
Volume Fraction ◽  
Interfacial Bonding ◽  
Mechanical And Thermal Properties ◽  
Fiber Volume ◽  
Pull Out ◽  
Interfacial Bonding Strength

Cf/SiC composites were fabricated through in situ growth of carbon nanotubes (CNTs) on three-dimensional needle-punched carbon fabric via chemical vapor deposition and polymer impregnation and pyrolysis process. The mechanical and thermal properties of the composites were investigated. The flexural strength and fracture toughness were decreased due to the fiber volume fraction loss and much shorter pull-out length of fibers which was caused by the higher interfacial bonding strength between fiber and matrix after the growth of CNTs. Brittle fracture character of CNTs was observed due to the strong interfacial bonding strength between CNTs and matrix. The parallel thermal conductivity and perpendicular thermal conductivity were improved to 14.5% and 8.0% respectively.

scholarly journals An approach to effectively improve the interfacial bonding of nano-perfused composites by in situ growth of CNTs

2021 ◽  
Vol 10 (1) ◽  
pp. 282-291
Author(s):  
Xingxing Chen ◽  
Ying Li ◽  
Ying Wang ◽  
Dingquan Song ◽  
Zuowan Zhou ◽  
...  
Keyword(s):  
Epoxy Resin ◽  
Bonding Strength ◽  
Impact Damage ◽  
High Strength ◽  
Interfacial Bonding ◽  
Resin Composites ◽  
Alloy Matrix ◽  
Interfacial Bonding Strength ◽  
Ni Alloy

Abstract Nano molding technology (NMT) has shown great potential in the preparation of metal/resin composites, which can integrate resin and metal into a lightweight, high-strength metal matrix composite. However, due to the poor interfacial bonding strength between metal and polymer, the application of the metal/polymer composites is limited. In this paper, we proposed a novel method to improve the bonding strength between Fe–Co–Ni alloy and epoxy resin by Nano Perfusion Technology (NPT), featuring in situ growth of carbon nanotubes (CNTs) in the pores on anodized Fe–Co–Ni alloy porous surface, followed by a perfusion of epoxy resin throughout the pores that had been in situ grown CNTs. Due to the “anchor effect” of CNTs, the bonding strength between the epoxy and the alloy matrix is improved. The results showed that the interfacial bonding between the in situ CNTs-modified alloy and the resin was significantly improved compared to the metal-resin composites surface treated with T-treatment in traditional method of NMT. The maximum interfacial bonding force of the alloy-CNTs/epoxy composite reached up to 691.80 N, which was 460, 315, and 267% higher than those by mechanical treatment, without CNTs and T-treatment, respectively. This work provides a new approach to protect metals or alloys from environmental corrosion, impact damage, and so on.

Mechanical Properties of Carbon Nanotubes Reinforced AZ91 Composites by Enhanced Interfacial Bonding

2017 ◽  
Vol 894 ◽  
pp. 38-41
Author(s):  
Guo Qiang Han ◽  
Wen Bo Du ◽  
Xian Du ◽  
Zhao Hui Wang ◽  
Ke Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Carbon Nanotubes ◽  
Load Transfer ◽  
Interfacial Bonding ◽  
Az91 Alloy ◽  
Enhancing Effect ◽  
Interfacial Bonding Strength ◽  
Ternary Carbides

The aim of this study is to enhance the interfacial bonding strength of carbon nanotubes (CNTs)/AZ91 composites by heat treatment (HT). Ternary carbides (Al2MgC2) were in situ formed and uniformly dispersed between CNTs and AZ91 matrix by 823K heat treatment of CNTs/AZ91 composites for 12 h. In situ synthesized Al2MgC2 can strengthen the interfacial bonding of CNTs/AZ91 composites, and guarantee an effective load transfer between matrix and CNTs. The HT-CNTs/AZ91 composites showed outstanding mechanical properties due to the excellent interface enhancing effect of Al2MgC2. Compared with pure AZ91 alloy, HT-CNTs/AZ91 composites exhibit improved ultimate tensile strength and 0.2% yield strength by 7% and 22% respectively.

Interfacial Bonding Strength of Graded ZrO2/NiCrAlY Coatings Accumulated by Detonation Gun Spraying

2003 ◽  
Vol 17 (08n09) ◽  
pp. 1152-1157
Author(s):  
Do Won Seo ◽  
Jab Kyoo Lim
Keyword(s):  
Bonding Strength ◽  
Functionally Graded ◽  
Interfacial Bonding ◽  
Mechanical And Thermal Properties ◽  
Crosshead Speed ◽  
Detonation Gun Spraying ◽  
Duplex Coating ◽  
Interfacial Bonding Strength ◽  
Graded Coatings ◽  
Detonation Gun

Functionally graded ZrO2/NiCrAlY coatings are produced by detonation gun spraying using spheroid powers as the feedstock. A commercial Ni-based alloy is used for metallic substrate. The composition and microstructure are changed gradually through the six-layer graded coatings that are beneficial for the improvement of mechanical and thermal properties of the coatings. The shear test is carried out to analyze the interfacial bonding strengths of graded coatings. And non-graded duplex coatings are tested for comparative study. The effects of cross-sectional size and crosshead speed on interfacial strength properties are also studied. Results show that interfacial strengths of graded coatings are increased gradually with increase of volumetric rate of NiCrAlY. The bonding strength of the functionally graded coating is about twice as high as that of the duplex coating. For duplex coating without metallic interlayer and below 5 mm/min, the interfacial bonding strength of ZrO2/NiCrAlY interface increase with increasing crosshead speed.

Thermal conductivity of biomimetic leaf composite

2017 ◽  
Vol 52 (13) ◽  
pp. 1737-1746 ◽  
Author(s):  
G Liu ◽  
R Ghosh ◽  
D Mousanezhad ◽  
A Vaziri ◽  
H Nayeb-Hashemi
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Composite Structures ◽  
Volume Fraction ◽  
Cell Structure ◽  
Matrix Material ◽  
Mechanical And Thermal Properties ◽  
Ceramic Fibers ◽  
Fiber Morphology ◽  
Fiber Volume

The venous morphology of a typical plant leaf affects its mechanical and thermal properties. Such a material could be considered as a fiber reinforced composite structure where the veins and the rest of the leaf are considered as two materials having highly contrast mechanical and thermal properties. The variegated venations found in nature is idealized into three principal fibers—the central mid-fiber corresponding to the mid-rib, straight parallel secondary fibers attached to the mid-fiber representing the secondary veins, and then another set of parallel fibers emanating from the secondary fibers mimicking the tertiary veins of a typical leaf. This paper addresses the in-plane thermal conductivity of such a composite by considering such a venous fiber morphology embedded in a matrix material. We have considered two cases, fibers having either higher or lower conductivity respect to the matrix. The tertiary fibers do not interconnect the secondary fibers in our present study. We carry out finite element based computational investigation of the thermal conductivity of these composites under uniaxial thermal gradients and study the effect of different fiber architectures. To this end, we use two broad types of architectures both having similar central main fiber but differing in either having only secondary fibers or additional tertiary fibers. The fiber and matrix volume fractions are kept constant and a comparative parametric study is carried out by varying the inclination of the secondary fibers. We find the heat conductivity in the direction of the main fiber (Y direction) increases significantly as the fiber angle of the secondary increases. Furthermore, for composite with metal fibers, the conductivity in the Y direction is further enhanced when composite is manufactured by having secondary fibers forming a closed cell structure. However, for composite with ceramic fibers, the conductivity of the composite in the Y direction is little affected by having secondary fibers closed. An opposite behavior is observed when considering conductivity of the composite in the X direction. The conductivity of the composite in the X direction is reduced with increase in the angle of the secondary fibers. Higher conductivity in the X direction is achieved for composite with no closed cells for composites with metal fibers. The results also indicate that for composites with the constant fiber volume fraction, morphology of tertiary fibers may not significantly alter material conductivities. In conclusion, introducing a leaf-mimicking topology in fiber architecture can provide significant additional degrees of tunability in design of these composite structures.

Interfacial Stresses and Void Nucleation in Discontinuously Reinforced Composites

1999 ◽  
Vol 122 (1) ◽  
pp. 86-92 ◽  
Author(s):  
T. C. Tszeng
Keyword(s):  
Stress State ◽  
Bonding Strength ◽  
Volume Fraction ◽  
Void Nucleation ◽  
Matrix Material ◽  
Interfacial Bonding ◽  
Von Mises Stress ◽  
Inclusion Problem ◽  
Matrix Interface ◽  
Interfacial Bonding Strength

This paper presents the theoretical predictions of the stress state at the inclusion-matrix interface in discontinuous metal matrix composites by the generalized inclusion method. In the author’s previous works, this method had been extended to the elastoplastic deformation in the matrix material. The present analysis of the ellipsoidal inclusion problem indicates that the regions at the pole and the equator of the particle/matrix interface essentially remain elastic regardless of the level of deformation, although the size of the elastic region keeps decreasing as deformation becomes larger. It was also found that, when the composite is undergoing a relatively large plastic deformation (strain), the maximum interfacial normal stress is approximately linearly dependent upon the von Mises stress and the hydrostatic stress. Based on the stress criterion for void nucleation, the author determined the void nucleation loci and nucleation strain for a composite subjected to an axisymmetric macroscopic stress state. The influence of interfacial bonding strength, inclusion shape, and volume fraction on the occurrence of void nucleation have been determined. The interfacial bonding strength in a SiC-aluminum system was re-evaluated by using existing experimental evidence. [S0094-4289(00)01301-3]

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