Aluminum Matrix Composites Reinforced with Alumina Nanoparticles (eBook)

Preface 6
Contents 8
Summary and Aim of the Work 11
1 State of the Art of Metal Matrix Nanocomposites 13
Abstract 13
1.1 Metal Matrix Nanocomposites 13
1.1.1 Type of Metal Matrices and Reinforcements 14
1.1.2 Strengthening Mechanisms 15
1.1.2.1 Load Transfer Effect 15
1.1.2.2 Hall-Petch Strengthening 16
1.1.2.3 Orowan Strengthening 17
1.1.2.4 CTE and EM Mismatch 18
1.1.2.5 Sum of Contributions 20
1.1.3 Preparation Methods and Properties 21
1.1.3.1 Liquid Processes 21
1.1.3.2 Semi-Solid Processes 24
1.1.3.3 Solid Processes (Powder Metallurgy) 25
1.2 Processing of Metal Powders 27
1.2.1 High-Energy Ball-Milling 28
1.2.1.1 High-Energy Ball Milling Variables 30
1.2.2 Equal Channel Angular Pressing 32
1.2.2.1 ECAP process variables 33
1.2.2.2 Consolidation of Particles by ECAP 35
1.2.3 Hot Extrusion 37
1.2.3.1 Extrusion Process Variables 38
1.2.3.2 Consolidation of Particles by Extrusion 38
1.3 Possible Applications of MMnCs 39
References 40
2 Experimental Methods 48
Abstract 48
2.1 Materials 48
2.1.1 Al Powders 48
2.1.2 Al2O3 Nanoparticles 49
2.2 Processing 49
2.2.1 High-Energy Ball Milling 49
2.2.2 Equal Channel Angular Pressing (ECAP) 50
2.2.2.1 Back-Pressure Equal Channel Angular Pressing (BP-ECAP) 50
2.2.3 Hot Extrusion 50
2.2.4 Rolling 51
2.3 Characterization Techniques 51
2.3.1 Scanning Electron Microscope (SEM) 51
2.3.2 Transmission Electron Microscopy (TEM) 51
2.3.3 X-Ray Diffraction (XRD) 52
2.3.4 Tensile and Compression Testing 52
2.3.5 Vickers Hardness 53
2.3.6 Density Testing 53
2.3.7 Instrumented Indentation 53
2.3.8 Dynamic-Mechanical Analysis (DMA) 55
2.3.9 Thermal Analysis 55
References 56
3 Consolidations of Al Powder and Dry Al2O3 Nanoparticles 57
Abstract 57
3.1 Powder Characterization 57
3.2 Powder Consolidation 60
3.3 Mechanical Characterization 62
3.4 Microstructural Characterization 63
References 68
4 Consolidation of Al Powder and Colloidal Suspension of Al2O3 Nanoparticles after 2 h Ball Milling 69
Abstract 69
4.1 Powder Characterization 69
4.2 Powder Consolidation 70
4.3 Mechanical Characterization 71
4.4 Microstructural Characterization 71
References 74
5 Consolidation of Al Powder and Colloidal Suspension of Al2O3 Nanoparticles After 16 h Ball Milling 75
Abstract 75
5.1 Powder Characterization 75
5.2 Powder Consolidation 78
5.3 Mechanical Characterization of Samples Consolidated by ECAP 79
5.4 Microstructural Characterization of the Samples Consolidated by ECAP 81
5.5 Mechanical and Functional Characterization of Samples Consolidated by Hot Extrusion and Cold Rolled 84
5.6 Microstructural Characterization of Samples Consolidated by Hot Extrusion and Cold Rolled 91
5.7 Discussion of the Results 95
5.8 Prediction of Experimental Results 102
References 104
6 Consolidation of AL Powder and Colloidal Suspension of Al2O3 Nanoparticles After 24 h Ball Milling 107
Abstract 107
6.1 Powder Characterization 107
6.2 Powder Consolidation 108
6.3 Mechanical Characterization 110
6.4 Microstructural Characterization 112
Reference 115
7 Consolidation of Micro- and Nano-Sized Al Powder 116
Abstract 116
7.1 Powder Characterization 117
7.2 Powder Consolidation 118
7.3 Mechanical Characterization 120
7.4 Microstructural Characterization 121
7.5 Discussion of the Results 125
References 130
8 Conclusions 133