Carbon Nanotube Reinforced Composites: Metal and Ceramic ...

More documents

Recommendations

Info

Figure 4.17 Wear rate vs carbon nanotube volume content for Cu/MWNT nanocomposites at different applied loads. Reproduced with permission from [45]. Copyright Ó (2003) Elsevier. 4.4 Wearj123 The CNTs were coated with electrodeless nickel to ensure good wetting between the copper matrix and nanotubes. Pores are formed in such nanocomposites processed by the PM route, ranging from 2.56% for composite filled with 4% CNT to 4.92% for sample with 16 vol% CNT. Figure 4.17 shows the variation of wear rate with nanotube content for the Cu/MWNT nanocomposites subjected to the pin-on-disk test at different applied loads. For applied loads below 30 N, the wear rate generally decreases with increasing nanotube content. At 50 N, the wear rate first decreases with increasing filler content up to 12 vol%, and then increases as the nanotube content reaches 16 vol%. This can be attributed to the high porosity content (4.92%) in the Cu/16 vol% MWNT nanocomposite. Thus, the wear rate of copper nanocomposites depends greatly on the microstructure and applied load under dry sliding conditions. Dong et al. also studied the sliding wear behavior of Cu/CNT nanocomposites prepared by PM ball milling and sintering (850 C) [46]. They also fabricated CF/Cu composites in the same way for the purpose of comparison. This is because the Cu/ CF composites are widely used for electric brushes and electronic component pedestals applications. They reported that the Cu/CNTnanocomposites exhibit lower friction coefficient and wear loss than those of Cu/CF composites due to the much higher strength of nanotubes. The optimum nanotube content in the nanocomposites for tribological application is 12–15 vol%. For Cu/MWNT nanocomposites prepared by molecular level mixing and SPS consolidation [Chap. 2, Ref. 87], CNTs are found to disperse homogeneously within the copper matrix; thus MWNT additions enhance the hardness of copper. Consequently, the wear resistance of copper is considerably improved by adding CNTs (Figure 4.18(a) and (b)). Compared with the copper nanocomposites fabricated by PM processing and slid at 30 N (Figure 4.17), Cu/MWNT nanocomposites densified by SPS exhibit much lower wear rates as expected.
124j 4 Mechanical Characteristics of Carbon Nanotube–Metal Nanocomposites Figure 4.18 Variations of (a) Vickers hardness and (b) wear rate of Cu/MWNT nanocomposites with carbon nanotube volume content under a load of 30 N. Reproduced with permission from [Chap. 2, Ref. 87]. Copyright Ó (2007) Elsevier. The tribological behavior of CNT–metal composite coatings will now be considered. Figures 4.19 and 4.20 show the respective variation of friction coefficient and wear volume with applied load for an Ni/MWNT coating subjected to the ball-onplate test under dry sliding conditions. The coating was deposited onto a carbon steel substrate in a nickel sulfate bath by electrodeless deposition [47]. The nanotube content in the coating as a function of MWNT concentration in the bath is shown in Figure 4.21. It is apparent that the nanotube content in the coating increases with the increase of MWNTconcentration in the bath up to 1.1 g /L 1 ,and thereafter decreases with increasing MWNTconcentration. A decrease of nanotube content in the coating at high MWNTconcentration is due to the agglomeration of nanotubes in the plating bath. From Figure 4.19, the friction coefficient decreases with increase of the applied load from 10 to 30 N. Further, the coating prepared with
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 119 and 120: 104j 4 Mechanical Characteristics o
Page 137: 122j 4 Mechanical Characteristics o
Page 147 and 148: 132j 5 Carbon Nanotube-Ceramic Nano
Page 189 and 190:
174j 6 Physical Properties of Carbo
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?