Marking magnesium alloys Buldum B. B. et al.

LIST OF FIGURES 2.1 Overview on literature review in this study 5 2.2 The division of composite based on it matrix and reinforcement 6

2.3 Marking magnesium alloys Buldum B. B. et al.

11 2.4 Aluminum - magnesium binary phase diagram ASM Handbook. 13 2.5 Secondary electron SEM micrograph of the CNTs used as reinforcement material for composite materials Bustamante R. P. et al, 2012. 15 2.6 SEM image of fracture surface of Mg-2wtMWCNTs. Homogeneous dispersion of MWCNTs in Mg matrix Bustamante R. P. et al, 2012. 15 2.7 Results from microhardness test of the Al 2024 –CNTs composites. By comparison pure Al and the Al 2024 hardness values under several processing conditions are displayed. Bustamante R. P. et al, 2012. 23 2.8 Schematic process of the pin-on-disc apparatus to study the wear behaviour of the Al2024–CNTs composites. Samples slide against the abrasive SiC paper at two different loads. Bustamante R. P. et al, 2012. 25 2.9 Grooves and scratch marks on the pin surface indicating abrasion. Lim C.Y.H et al, 2005 27 2.10 The appearance of the aluminium alloy surface after its corrosive wear in the acid rain Pokhmurskii V.I. et al, 2011. 27 2.11 Schematic diagram showing on a adhesive wear b oxidative wear Kumar A. and Singh S., 2011. 30 2.12 Schematic on fatigue wear on metal material Kumar A. and Singh S., 2011. 29 3.1 Macroview of magnesium aluminium alloys powder 30 ix 3.2 Macroview of multi-walled carbon nanotubes. 31 3.3 Scirocco Mastersizer 2000 Particle Size Analyzer 32 3.4 The powder metallurgy sequence for Magnesium alloys composite 33 3.5 Planetary Ball Mill Machine model: Insmart 34 3.6 Analytical Balance Excellent Model: Mettler Toledo 34 3.7 150 Ton Hydraulic Press Machine 35 3.8 The front view of punch and die for cold compaction process 36 3.9 The top view of punch and die for cold compaction process 36 3.10 The green compact pallet formed after compaction process 36 3.11 a LT Horizontal Tube Furnace Model: TF70-1600 b Sintering graph 37 3.12 Front view of plunger and die for extrusion process 38 3.13 Top view of plunger and die for extrusion process. 38 3.14 The extruded specimen. 38 3.15 Metkon Micracut 125 Diamond Cutters. 39 3.16 The BUEHLER Beta Twin Variable Speed Grinder-Polisher 39 3.17 The specimen for density, hardness and wear test. 39 3.18 The Electronic Densimeter MD-300S AlfaMirage, Japan 40 3.19 The Mitutoyo Mvk-Micro Vickers Hardness Testing Machines 41 3.20 The Ducom TR-20LE Pin-on –Disc wear testing machine. 43 3.21 The controller of the wear and friction-testing machine. 43 3.22 Scanning Electron Microscope SEM Zeiss Evo® 50 model 44 4.1 Particle size result for Magnesium alloy powder. 46 4.2 The graph of density versus composition for the metal matrix composite 47 4.3 The graph of void content versus composition for the metal matrix composite 49 4.4 The graph of Vickers Hardness versus composition for the metal matrix composite 51 4.5 The macro view of the worn surface on pin surface 53 x 4.6 The graph of Specific Wear Rate versus sliding speed for various composition metal matrix composite 54 4.7 The wear temperature of metal matrix composite. 56 4.8 The Coefficient of Frictionof the Metal Matrix Composite 57 4.9 The Scanning Electron Microscope SEM on the worn surface of the Metal Matrix Composite for sliding speed of 4.5 ms, sliding distance of 5000 m and applied load of 40 N . 59 4.10 The Scanning Electron Microscope SEM on the worn surface of the Metal Matrix Composite for 0.5 wt of CNT with sliding distance of 500 m and applied load of 40 N. 61 4.11 Fatigue crack happen at high sliding speed 62 4.12 The EDX analysis that show present of oxide element at the fatigue crack area. 63 4.13 The mechanically mixed layer MML on the pin surface due to thermal softening. 64 4.14 The EDX analysis shows the presence of Fe, Al, O and Mg on MML area 64 4.15 The protruding at the edge of the pin indicate thermal softening mechanism 65 xi LIST OF ABBREVIATIONS, SYMBOLS AND NOMENCLATURES MMC - Metal Matrix Composite CMC - Ceramic Matrix Composite PMC - Polymer Matrix Composite PM - Powder Metallurgy HCP - Hexagonal Closed Packed SEM - Scanning Electron Microscope PSA - Particle Size Analyzer ASTM - American Standard Test Method XRD - X-Ray Diffraction Mg - Magnesium SiC - Silicon Carbide Al 2 O 3 - Alumina CNT - Carbon Nanotube SWNT - Single Wall Carbon Nanotube MWNT - Multi Wall Carbon Nanotube Al - Aluminium Ti - Titanium C - Carbon W - Tungsten WC - Tungsten Carbide Cu - Copper B - Boron Si - Silicon xii ºC - Degree Celcius Q - Total volume of wear debris produced W - Total normal load H - Hardness of the softest contacting surfaces K - Dimensionless constant L - Sliding distance HV - Vickers hardness F - Load in kgf d - Arithmetic mean of two diagonals, d1 and d2 in mm m 2 - mass g of the specimen after testing m 1 - initial mass g of the specimen � - density gmm3 of the specimen F N - normal load N applied on the specimen during sliding SD - total sliding distance m T - theoretical composite density D - Density of resin d - Density of reinforcement R - Resin weight r - Reinforcement weight V - Void content volume T d - theoretical composite density M d - measured composite density Wt - weight percentage xiii CHAPTER 1 INTRODUCTION

1.1 Research Background