Carbon Nanotube Reinforced Composites: Metal and Ceramic ...

More documents

Recommendations

Info

Figure 4.10 (a) Compressive true stress–strain curves of pure Cu, and Cu/MWNT nanocomposites prepared by molecular level mixing and spark plasma sintering. (b) Young s modulus and compressive yield strength vs carbon content for Cu/MWNT nanocomposites. Reproduced with permission from [Chap. 2, Ref. 86]. Copyright Ó (2005) Wiley-VCH Verlag GmbH. 4.2 Tensile Deformation Behaviorj115 point due to homogenous dispersion of nanotubes in the copper matrix. The yield strength of copper improves dramatically with the incorporation of nanotubes. The yield strength of Cu/5 vol% MWNT nanocomposite is 360 MPa, which is 2.4 times that of Cu (150 MPa). The compressive yield strength increases to 455 MPa when the nanotube content reaches 10 vol%, being 3 times that of Cu. This is attributed to the high load-transfer efficiency of nanotubes in the matrix as a result of strong interfacial bonding between the copper matrix and nanotubes through molecular level mixing. From Equation 4.4, the strengthening efficiency of the reinforcement (R) can be expressed as S/2, thereby yielding: sc ¼ smð1 þ Vf RÞ ð4:15Þ R ¼ ðsc smÞ : ð4:16Þ Vf sm
116j 4 Mechanical Characteristics of Carbon Nanotube–Metal Nanocomposites Figure 4.11 Experimental and theoretical yield strength of Cu/ MWNT nanocomposites as a function of carbon nanotube content. Reproduced with permission from [Chap. 2, Ref. 89]. Copyright Ó (2008) Wiley-VCH Verlag GmbH. The R values for the Cu/5 vol% MWNTand Cu/10 vol% MWNTnanocomposites are determined to be 14 and 20.3, respectively. These values are much higher than those of SiC particle and SiC whisker reinforcements. Figure 4.11 shows a comparison between theoretical and experimental compressive yield strength vs nanotube content for Cu/MWNTnanocomposites. Theoretical predictions are made assuming the aspect ratios of nanotubes to be 40, 50 and 60. Apparently, the measured yield strength agrees reasonably well with the estimated values from Equation 4.4 for the composites with aspect ratios of 40 and 50. In addition to the load transfer mechanism, metallurgical factors, such as refinement of matrix grains and higher dislocation density resulting from the coefficient of thermal expansion between the matrix and nanotubes, also contribute to the strength of nanocomposites [20]. 4.2.4 Nickel-Based Nanocomposites Electrodeposition is widely known as an effective technique for depositing dense nanocrystalline nickel coatings for mechanical characterization. Nanocrystalline nickel coatings generally exhibit much higher tensile strength and stiffness but poorer tensile ductility compared with microcrystalline Ni. It is considered that CNTs with superior tensile strength, stiffness and fracture strain can further improve the mechanical properties of Ni coatings. Table 4.5 lists the tensile properties of nanocrystalline Ni and nanocrystalline Ni/MWNT composite prepared by electrodeposition [Chap. 2, Ref. 100]. The hardness and tensile strength of Ni/MWNT composite are considerably higher than those of nanocrystalline Ni. The tensile elongation of nanocrystalline Ni decreases very slightly by incorporating MWNTs. It can be said that the tensile elongation is quite similar and not affected by the nanotube additions. Sun et al. [Chap. 2, Ref. 105] demonstrated that
Page 2 and 3:
Sie Chin Tjong Carbon Nanotube Rein
Page 4 and 5:
Sie Chin Tjong Carbon Nanotube Rein
Page 6 and 7:
Contents Preface IX List of Abbrevi
Page 8 and 9:
5 Carbon Nanotube-Ceramic Nanocompo
Page 10:
Preface Carbon nanotubes are nanost
Page 13 and 14:
XII List of Abbreviations HIP hot i
Page 16 and 17:
1 Introduction 1.1 Background Compo
Page 18 and 19:
Figure 1.2 Transmission electron mi
Page 20 and 21:
1.3 Synthesis of Carbon Nanotubes 1
Page 22 and 23:
MWNTs can be as high as 70% of the
Page 24 and 25:
Figure 1.7 In situ TEM images recor
Page 26 and 27:
1.3 Synthesis of Carbon Nanotubesj1
Page 28 and 29:
show TEM images of MWNTs synthesize
Page 30 and 31:
Since then, large efforts have been
Page 32 and 33:
1.3.4 Patent Processes Carbon nanot
Page 34 and 35:
1.4 Purification of Carbon Nanotube
Page 36 and 37:
Table 1.3 Patent processes for the
Page 38 and 39:
Figure 1.13 Schematic illustration
Page 40 and 41:
1.5 Mechanical Properties of Carbon
Page 42 and 43:
Figure 1.14 Carbon nanotubes in hig
Page 44 and 45:
Figure 1.15 In situ tensile deforma
Page 46 and 47:
Table 1.7 Theoretical and experimen
Page 48 and 49:
Nomenclature ~a 1 , ~a 2 Unit vecto
Page 50 and 51:
carbon nanotubes. Physical Review L
Page 52 and 53:
70 Jang, I., Uh, H.S., Cho, H.J., L
Page 54 and 55:
108 Shelimov, K.B., Esenaliev, R.O.
Page 56 and 57:
Bonnamy, S., Beguin, F., Burnham, N
Page 58 and 59:
2 Carbon Nanotube-Metal Nanocomposi
Page 60 and 61:
isostatic pressing. In certain case
Page 62 and 63:
This implies the absence of effecti
Page 64 and 65:
coating material, the plasma gun an
Page 66 and 67:
Table 2.4 Changes in the size and v
Page 68 and 69:
Figure 2.6 (a) Low and (b) high mag
Page 70 and 71:
Figure 2.8 SEM micrographs showing
Page 72 and 73:
Figure 2.11 Bright field TEM microg
Page 74 and 75:
Figure 2.13 TEM image of bulk Al/5
Page 76 and 77:
2.5 Magnesium-Based Nanocomposites
Page 78 and 79:
limited improvement in ultimate ten
Page 80 and 81: Figure 2.18 SEM micrographs of the
Page 82 and 83: Figure 2.19 (a) Low and (b) high ma
Page 84 and 85: Figure 2.22 SEM micrographs of (a)
Page 86 and 87: Figure 2.25 (a) TEM micrograph show
Page 88 and 89: 2.8 Transition Metal-Based Nanocomp
Page 90 and 91: Figure 2.27 TEM image of electrodep
Page 92 and 93: Figure 2.29 SEM micrographs of (a)
Page 94 and 95: Figure 2.31 Schematic representatio
Page 96 and 97: einforcement content SiCp/Al compos
Page 98 and 99: Materials Science Forum, 534-536 (P
Page 100 and 101: composite. Materials Science and En
Page 102: 111 Cha, S.I., Kim, K.T., Arshad, S
Page 105 and 106: 90j 3 Physical Properties of Carbon
Page 115 and 116: 100j 3 Physical Properties of Carbo
Page 117 and 118: 102j 3 Physical Properties of Carbo
Page 119 and 120: 104j 4 Mechanical Characteristics o
Page 129: 114j 4 Mechanical Characteristics o
Page 147 and 148: 132j 5 Carbon Nanotube-Ceramic Nano
Page 181 and 182:
166j 5 Carbon Nanotube-Ceramic Nano
Page 183 and 184:
168j 5 Carbon Nanotube-Ceramic Nano
Page 185 and 186:
170j 6 Physical Properties of Carbo
Page 187 and 188:
Page 189 and 190:
Page 191 and 192:
Page 193 and 194:
Page 195 and 196:
Page 197 and 198:
Page 199 and 200:
Page 201 and 202:
186j 7 Mechanical Properties of Car
Page 203 and 204:
Page 205 and 206:
Page 207 and 208:
Page 209 and 210:
Page 211 and 212:
Page 213 and 214:
Page 215 and 216:
Page 217 and 218:
Page 219 and 220:
Page 221 and 222:
Page 223 and 224:
Page 225 and 226:
Page 227 and 228:
Page 229 and 230:
Page 231 and 232:
Table 8.1 Patent processes for maki
Page 233 and 234:
218j 8 Conclusions development of c
Page 235 and 236:
220j 8 Conclusions Figure 8.2 TEM m
Page 237 and 238:
222j 8 Conclusions increase in Vick
Page 239 and 240:
224j 8 Conclusions References 1 Cha
Page 241 and 242:
226j 8 Conclusions nano-matrix. Scr
Page 243:
228j Index l laser ablation 7 load
show all

Carbon Nanotube Reinforced Composites: Metal and Ceramic ...

Create successful ePaper yourself

Delete template?

Save as template?