Index

Ablation energy (acrylic) 219 Abrasion (workpiece surface) 85 Abrasive water jet cutting

general 179-184 cutting speeds 182, 184

ABS (acrylonitrile-butadiene-styrene) 93, 94, 101-103

Absorptivity (see also Reflectivity) aluminium (and Anodised AC) 82-86 copper 88-89 losses from cut zone 218-222 metals, general 71-72, 89-90 Nd:YAG light 174 non-metals 91

Absorbing coatings 85 AC, see Alternating current Accidents, see Safety Acetone 161-163 Acrylic (see also Beam print, Mode print)

Focal point testing 28-29, 226-227 Laser beam analysis 16, 45, 149,218-222 Mechanism of cutting 91, 93, 96-98 Power measurement 218-219 Quality of cut 96-98, 145 Speed of cutting 97, 102 Vapour 96, 119, 155

Acrylonitrile-Butadiene-Styrene, see ABS Air as a cutting gas

metals 39, 40, 70, 75, 84 non-metals 91-98, 102, 109-110 piercing 31-32

Air, compressed 40,119,163 Alcohols 161, 162, 163 Alignment

beam 56-70 ReNe laser 125-128 laser 150-152, 154 nozzle 134-138, 157-158 targets 121, 222, 124

Alloy steels 56-70 Alternating current (AC) excitation 190, 201 Alternative cutting methods 173-187 Alumina (see also Aluminium oxide) 111-113 Aluminium alloys 6, 39, 71-72, 82-86, 201 Aluminium oxide (AI20 3) see also Anodised

AI) 72, 82-85,111-113 Ammonia (NR3) 100

Annealed steel 68-69 Annealing acrylic 98 Anodised aluminium 84-85,130 Antireflection (AR) coatings 160 AR (antireflection) coatings 160 Argon (see also Inert gas cutting jet) 64 Aspect ratio (of details) 32 Aspheric lens 228 Asymmetric stretch mode (C02) 190 Austeritic stainless steel 57-65 Auxiliary gas jet (see also Dross jet) 64, 67,

74, 77-81 Avalanche effect 10-12, 15, 196 Axial symmetry of energy input 16, 21, 44-51

Batch production 81 Beam alignment 117-128 Beam expansion (see Collimators) Beam print 16, 118-125, 163 Bending 69, 85 Bending mode (C02) 190 Biscuit 115 Black body 223 Blanks (preformed) 144-145 Blue flash test 129-130 Boiling (see also Vaporisation) 112 Brass 88, 132 Bright mild steel 41 Bronze 88 Burning of workpiece

mild steel 32-39, 43-44, 47, 53, 141, 155-156, 158

non-metals 94-95 titanium 75

Burns (skin) 165-166 Butadiene 100, 103

Cable stripping 115 Cadmium 43 Capital costs 3, 186, 187,201 Carbon 67-68, 92, 101, 109 Carbon content 67-68 Carbon dioxide (C02) 8, 9, 12, 15, 18-19,67,

190-195 Carbon dioxide lasers, see Lasers, CO2

Carbon fibre 114

242

Carbon steels 56,67-70 Cardboard 108-110 Carpet 115 Cast acrylic 98 Cavity (optical or laser) see Laser cavity Cellulose 92, 108-109 Centralisation, see Alignment Ceramics 111-113 Ceramic scribing 111-113,174,175 Checklist (troubleshooting) 153-154 Chemical degradation 91,92,98-101 Chromium/chromium oxide 58, 61--62 Chutes 146 Circular polarisation (see also Polarisation)

47-48, 125 Clamps 146 Clean cutting 64-65 Cleaning fluids

for optics etc 161 for absorption 85

Cleaning Lenses 161-162 Mirrors 163

Clipping 123, 129, 133, 137-138, 158 Clipping test (alignment) 137-138 Cloth 115 CNC, see Computer control CO2 , see Carbon dioxide CO2 energy spectrum 12, 190-194 CO2 lasers, see Lasers, CO2

Coander nozzle 143 Coherence 196 Cold rolled mild steel 40-41 Collimators 125, 128, 228 Composites 114-115 Compressed air, see Air, compressed Computer control (CNC) 3, 27, 35-8 Conductive losses 206-210, 215-217 Conductivity, see Thermal conductivity Contamination (of oxygen) 49, 67 Continuous wave (c.w.) 4, 14,52,83, 113 Convection effects 30, 65, 83, 206-210, 217-

218, 222, 224-225 Convergence 227 Cooling, see Laser cooling, Workpiece

cooling Copper 6, 71-72, 88-89, ~32, 164 . Corner burning, see Burmng of workpIece Corner overshooting 35-38 Corner ripples 37 Corrosion 24, 41, 43, 63-64 Corrosion resistance 62--64, 84 Cracking 69,76,97-98, 112-113 Cross wire targets 121, 122, 124, 151 Cut front inclination 34-35 Cut initiation (see also Drilling) 31-34, 38,

43, 86 Cut termination 34-36 Cuts (skin etc) 165-166 Cutting heads 2,5,40, 134-135 Cutting jet, see

Air as cutting gas, Gas jet, Inert gas cutting jet, Oxygen cutting jet

Cutting speed, see Speed of cutting

Index

Cutting speed curve (polymers) 104-105 Cutting speed equation (polymers) 106-108 Cutting speed forecasting 104-108 Cutting speed ramping 38 Cutting trails 103, 105, 115 c.w., see Continuous wave Cut width, see Kerf width

Damage to the workpiece 146 DC, see Direct current De-excitation of CO2 193, 196 Degreasing agents 41 Depolarisation (see also polarisation) 47-48,

125 Depolariser mirrors 125 Depolymerisation 91,98 Depth of focus (see also Effective depth of

focus) 28-29, 95, 128-131,225-229 Design of lasers (see also Lasers) 18-22,200-

203 Destructive interference (see also

Interference) 17-18 Die boards 91, 108,224 Diffraction 160, 163 Direct current (DC) excitation 190-203 Dirt on optics (see also Cleaning) 160-164,

228,229 Discolouration of the workpiece 39 Distortion, see Thermal distortion Divergence 163, 227 Doughnut (donut) modes, see Modes,

Gaussian Drilling

general 31-34) 85-86, 108 alignment test 137-138 blast 32, 42 ceramics 111-113 focusing test 130 high reflectivity metals 86 Nd:YAG 174 pulsed 31,38,42,86

Dross aluminium alloys 84 steel, low alloy 64, 66, 67, 70 steel, mild 39, 42, 43, 44, 46, 47 steel, stainless 59, 61 non-ferrous metals 73, 74, 75, 76, 77-81, 84 titanium alloys 74, 75, 76, 77-81

Dross jet (see also Auxiliary gas jet) 64, 77, 81

Duplex stainless steel 58--65

- ~

lIe level 17 lIe2 level 17 Edge sealing 115

Index

Effective depth of focus 29, 95, 128 Efficiency

cutting 83, 91, 206-225 lasers 193

Einstein, A. 189 Electric discharge (see also Plasma discharge)

8, 19, 190, 193, 195-196 Electrocution 148, 171-172 Electrical pumping 197 Emissivity 222-223 Energy balance, cut zone 206-211 Energy cycle, CO2 lasers 195-197 Energy density (see also Power density,

Mode, Focal spot diameter) focused beam 6, 19,28-29,44-45, 129,

225-229 unfocused beam 16,44-45,166,225-229

Energy input, cut zone 27, 28-31, 44-51 Energy spectra

general 8, 9, 12, 13 CO2 12, 190-194 N2 12, 193-194

Epoxy resin 93,103 Excitation

C02 8-9, 190-196,201 N2 10, 12, 193-194,201

External mirrors 120-128 Extruded acrylic 98 Eye safety 125, 167-168

Fabric 115 Fabry-Perot resonator 202 Fast flow 13, 14, 15,201-202 Fatigue life 70, 71, 72, 76 Ferritic stainless steel 57, 58-65 Fibreboard 108-110 Fibreglass 103, 114 Filtration ( air) 163 Fire hazards 75, 172 First aid 167 Flame cutting

general 184-186 cutting speeds 185

Flame polished edge 96-98 Flames 94-95,96 Flash test 129-130 Flexible materials 101, 146 Flight tubes 166 Flimsy materials 101, 146 Focal depth, see Depth of focus Focal length 6, 29, 40, 95, 128-129,228 Focal length check 160 Focal spot positioning 29,117, 128-131 Focused spot diameter 6,28-29,47,103, 160,

173, 225-229 Focusing light 6,7,18,19,29,30, 103, 128-

131,160,173,225-229 Foodstuffs 115 Formica 103 Free cutting steels 67

Fume extraction 99, 100, 168, 169 Fumes (safety)

general 168-171 metals

beryllium 169 cadmium 169 cobalt 169 copper 169 iron 169, 170 lead 170 magnesium 170 manganese 170 nickel 170 titanium 169, 170 tungsten 169 vanadium 170 zinc 169, 170

non-metals acrylic 96,119,155 ceramics 171 degreasing agents 169 glass 171 oil 169 polyurethane 171 PIFEl71 PVC 170 thermosets 171 wood 171

Furniture manufacture 108

Galvanised, see Zinc coated Gas chamber 77 Gas dynamic lasers 190, 201 Gas dynamics, nozzles 138-144

243

Gas jet (see also Auxiliary gas jet, High pressure gas jet, Inert gas cutting jet, Oxygen cutting jet) 1, 7, 155

Gas mixtures (laser) 8-13, 195-196 Gas pressure

cutting 5, 94-95, 132-133, 138-142, 155 laser 8

Gas recirculation 14 Gauge plate 68 Gaussian distribution (see also Modes,

Gaussian) 17 Gaussian modes, see Modes, Gaussian Glass 113-114 Glass reinforced plastic 103, 114 Glow discharge 195 Goggles (see also Eye safety) 86 Gold 7,89, 164, 174 Grease spot test (alignment) 136 Grinding 64 Ground flat stock 68

Hardboard 108-110 Hardened steel 68-69 Hardening (see also Heat treatment, Heat

affected zone)

244

Hardening (continued) steels 68-70 titanium 75-76

Hastelloys 87 HAZ, see Heat affected zone Heat affected zone

general 3, 68, 177-178, 183, 185-186 carbon steel 39, 40, 68-70 77 stainless steel 63 titanium 75-Tl, 80

Heat sensitive paper 121-123 Heat treatment 20, 68-70 Height sensors 133 Helium (He) 8, 12, 13, 15, 154, 193--196 Helium-neon (HeNe) laser, see Lasers, HeNe High order modes, see Modes, high order High pressure gas jet 64, 74 Hole cutting 32-34 Honeycomb (support) 145 Hot dipped, see Zinc coated mild steel Hot rolled mild steel 41-42 Hydrogen chloride (HCI) 93, 100, 170--171 Hydrogen cyanide 93,100,170--171

Inclination, cut edge 47-48 Inconels 87 Inert gas cutting jet 64-65, 74, 76-81, 84, 87,

141 Interference fringes 219-222 Initiation of cutting 31 Injection mouldings 94 Interlocks 171-172 Internal mirrors 8, 17 Ionisation (vapour) 129 Iron alloys (see also Steels) 56-70 Iron fumes 169,170 Iron oxidation 211-215 Iron oxides 61, 211-215

Jigs 81, 101, 128, 144-146, 167 Job shop work 4, 115

KCl (potassium chloride) 160 Kerf width 3, 39, 47, 93,108,161,174,178,

186 Knots (in wood) 108

Laser alignment 150 Laser beam analyser 45,56, 150,237 Laser cavity 8, 10, 18-21, 151,202,203 Laser cooling 13, 14,21,22,201-202 Laser cutting steels 27 Laser design (see also Lasers) 18-22,200--203 Laser efficiency 8, 10 Laser power 6, 106, 210 Lasers

C027-22, 189-203, 237

HeNe 125-128, 167 Nd:YAG 175-176 N212

Laser tuning 147-150 Lasing 8,9, 191, 196 Leather 115 Lenses

general 2, 5-7,AO, 122 alignment 122-125, 162 cleaning 161-162

Index

damage 30, 65, 122, 160-161,228-229 focal length 6, 29, 40, 95, 128-129,228 high pressure 65 holders 122 mount 122 multiple 227-228

_ Light amplification 10, 11, 190-196 Linear polarisation 47-48 Lower lasing level 191

!'.:'Iach shock disc 142-143 Maintenance 154-155, 156, 161-164,202 Manganese 67 Martensitic stainless steel 58, 59-65 Material (cloth) 115 Material specification 159 Maximum thickness 50,82,178,183,185-187 MDF (medium density fibreboard) 108-110 Mechanisms of cutting see melt shearing,

oxidation reactions and vaporisation Melting points

ceramics 111 metals 72

Melt shearing 59-60,73,75,77-81,91-96, 141

Mesh (support) 145 Metal fume fever 168 Micro-Plasma cutting 119 Mild steel

general 4, 23--56 burning see Burning, mild steel initiation of cut 31-34 mechanism of cutting 24, 211-213, 215-225 mode sensitivity 44-47 nozzle alignment 49-50 oxidation reactions 211-213 oxygen jet symmetry 48-50 polarisation effects 47-48 pulsed laser cutting 50--56 quality 27-31, 44-51 speed 26 surface finish 40-44 termination of cut 34-35 thickness, maximum 26, 209-210

Mill scale 41 Mirrors _ beam steering (external) 117-118, 120--128,

154, 163--164 cleaning 163--164 laser (internal) 8, 12, 19,20, 147-149, 163,

Index

202-203 Misalignment, see Alignment Miscellaneous materials 115 Mode

general 16-22,27,44-47,95, 103, 158, 162-163,197-200,227

analysis 149-150 doughnut 16-19,21, 198-199 Gaussian 16-21,45, 103, 198--200,202-203,

227 high order 16-18, 199 multi-, see Multimodes Nd:YAG 174-176

Mode burn, see Mode print Mode print 16, 45, 118-119, 148--150,218-

222 Molybdenum 164 Monel 87 Monochromatic light 192, 227 Moving optics (alignment) 117-128 Multimodes 16-18,45, 198--200

Nail bed (support) 144-145 Neodynium:YAG lasers, see Lasers,

Nd:YAG Nesting components 3 Nd:YAG lasers 175-176 Nd:YAG laser cutting 173-176 Nickel alloys 71-72, 87 Nimonics 87 Nitrogen (Nz)

as cutting gas 64 as laser gas 8, 10, 12, 13, 15, 193-196 lasers 12

Non-ferrous metals 4, 5, 71-89 Non-metals (see also Polymers, Wood and

Ceramics) 4, 5, 7, 91-115, 236 Nozzles

general 5, 44, 48-51, 60, 77-81, 96, 131-144, 156-159,237

alignment 134-138, 157-158 cleaning 157 coander 143 contamination 153, 154 damage 156 diameters 134 design 131-132, 134,237 gas dynamics 138-143, 237 misalignment 49-51,137,157-159 non-circular 142-143 standoff 132-133, 156

Nylon (polyamide) 93, 102, 114

Oil contamination (optics) 163 on steel 41-42 soluble 39

Optical cavity design 202-203 Optical chain 118, 123, 163, 166

Optical fibres 173, 174 Optical pumping 197 Optical safety, see Eye safety Output coupler, see Output window

245

Output window 10,147,151,152,163 Overheating of workpiece, see also Burning)

28,31,39,83 Overshooting, see Corner overshooting Oxidation of the cut edge 71, 75, 76-81, 211-

215 Oxidation reactions

aluminium 82-85 copper 88 iron (see also steel, mild) 211-215 nickel 87 steel, mild 4, 23-25, 30, 211-215 steel, stainless 59, 213-215 titanium 75 zinc 88

Oxides (see also Oxidation reactions) general 66-72, 211-215 chromium 213-215 iron 211-215 nickel 213-215

Oxide dissociation 111-112 Oxy-acetylene cutting 184-186 Oxygen contamination 49 Oxygen cutting jet (see also Gas dynamics

and Oxidation reactions) general 24, 25, 30,44 pressure 26,60,64 symmetry requirements 48-51 non-ferrous metals 75-77,84,87

Oxygen: liquid 49 Oxygen pressures 26,60,64 Oxygen purity 49

Paint on steel 43 Paper 108--111 Patel, C.K.N. 189 Perforating (see also Drilling) 108 Perspex, see Acrylic Phenolic resin 93, 103 Photons 9, 10, 15, 192 Physics, cutting 205-229 Physics, laser 189-202 Pickled and oiled steel 42 Piercing, see Drilling Pine (see also Wood) 109-110 Pitot tube 133, 139, 141 Plasma 129 Plasma arc cutting 176-179 Plasma discharge (see also electric discharge)

21 Plasma torch 177-179 Plastics, see Polymers Plexiglass, see Acrylic Plywood 91, 108-110, 171 PMMA, see Acrylic Pointing direction 121, 126, 148

246

Polarisation 44, 47-48 Polished edge (acrylic) 96 Polyacetal 92, 93, 98 Polyamide (nylon) 93, 102, 114 Polycarbonate 100, 102 Polyethylene 93, 102 Polymers gener~93-108, 174,223-224 fumes 170--171 quality of cut 93-101 speed of cutting 101-108

Polymethyl methacrylate, see Acrylic Polypropylene 93, 102 Polystyrene 93, 102 Polytetrafluoroethylene (PTFE) 171 Polythene, see polyethylene Polyurethane 93, 100, 171 Polyvinyl chloride (PVC) 93, 100, 102, 170 Population inversion 197 Potassium chloride (KCl) 160 Power density (see also Energy density) 28,

29,103 Power of lasers 28, 154, 210 Power ramping 38 Preformed blanks 144-145 Preheating 113 Pressings, trimming of 81 Pressure fluctuations 132-133, 138-144 Primary energy losses 207 Printed acrylic 96, 98 Prisms 126 Process parameters 24 Profiling techniques, alternatives 173-187 Profilometry 45, 46 Programming, see Computer control PTFE (polytetrafluoroethylene) 171 Pulse frequency 54, 55 Pulsed lasers (see also Pulsed laser cutting) 10 Pulsed laser cutting 4, 38, 50--56, 67, 86, 111-

113 Pulsed laser output 201 Pulse length 54, 55 Pumping (see also Excitation) 197 PVC (Polyvinylchloride) 93,100,102,170 Pyrex 113, 171

Q-switching 176 Quality of cut

acrylic 96--98, 145 mild steel 27-31, 44-51, 68-70 polymers 93-101 stainless steel 60-65 titanium 77-81 wood 108-109

Quantum mechanical selection 192 Quantum mechanics 190 Quenching 69

Radiation 10, 165,206--209,223 Radiative losses 206--210, 217-218, 222-224

Index

Radio frequency (RF) excitation 20, 190 Ramping of power 38 Recirculation of gas 14 Reflection 221-222 Reflections, unwanted (see also Clipping) 86,

94, 123, 166, 168 Reflective losses 206--209,217-222 Reflectivity (see also Absorptivity and

Mirrors) gener~ 6 ~uminium 82-86 copper 88-89 losses from cut zone 206--209, 218-222 non-ferrous metals 71, 72 non-metals 91, 113

Relaxation, spontaneous 196 Reliability of cutting 27 Residu~ stress 94, 98 Resolidified melt 93 Resonant energy transfer 193 RF, see Radio frequency Ripples on corners 37 Robotic system 2 Roots blowers 21, 202 Roughening the workpiece 85 Roughness, cut edge (see also Striations) 46,

50 Rubber 93. 100, 101, 103, 146 Rumbling 64, 75 Running costs 3, 14, 186--187 Rust, see Corrosion Rusty steel 43-44

Safety 125, 165-174 Safety goggles 86,125,167,168 Sampling the beam 150 Scratches on optics 149, 161 Scribing ceramics 111-113, 174, 175 Sealing of edges 115 Secondary energy losses 207 Servicing 154-155 Setting up for cutting 117-152 Sharp details 37 Shock 165, 167 Shock waves 142-143 Shopfitting 109 Shot blasted steel 43 Shutter 120, 129 Sign manufacture 4, 96 Silica (silicon dioxide, Si02) 43, 113 Silicon 66 Silicon dioxide (silica) 43, 113 Silicon iron 66 Silicosis 171 Silver 8 Skin damage 165-166 Slot width, see Kerf width ~Slow flow 13,15,201,202

Smoke 98, 100, 109, 171 Soluble oil 39

Index

Sparks analysis of 211-215 nrisalignment50-51, 136, 157 test (alignment) 136, 157

Spatial coherence 196 Spatter

lenses 49, 65, 160-162 nozdes 131, 132, 138, 154, 156,229

Spectrum (energy), see Energy spectra Speed of cutting

general 3, 24,30,31, 73,104-108 ABS 102 acrylic 102 aluminium 82, 85 brass 89 ceramics 111, 113 copper 89 fibreboard 110 fibreglass 103 formica 103 nickel 87 nylon 102 phenolic resin 103 plastics 102-108 polycarbonate 102 polyethylene 102 polymers 101-108 polypropylene 102 polystyrene 102 polythene 102 PVC 102 rubber 101, 103 steel, mild 26, 40 steel, stainless 60 titanium 75 wood 108-110

Speed forecasting 104 Spherical aberration 228 Spikes (support) 144-145 Spontaneous emission (or relaxation) 10, 11,

15, 196 Spot size, see Focused spot diameter Spring steel 65-66 Stable cavity (stable resonator) 20, 21,

202 Stainless steel

general 4, 56-65 austenitic 57 duplex 58 ferritic 57 high pressure cutting 64-65 martensitic 58 mechanism of cutting 5s-60, 213-215 qUality of cut 60-65 speed of cutting 60

Standoff (nozde) 132-133 Start up holes (see also Drilling) 31-34, 38 Steel, mild, see Mild steel Steels

alloy 56-67 carbon (see also Mild steel) 67

free cutting 67 laser cutting 27 mild, see Mild steel spring 65-66 stainless, see Stainless steel structural 65-66 tool 65-66

Stefan-Boltzmann law 223 Stimulated emission 10, 11, 197

247

Stop-start marks (see also cut imitation and cut termination) 38

Stress relief 94 Striations 24, 25, 44, 46, 52,56 Stripping of insulation 115 Structural steels 65-66 Suction (nozdes) 132-133 Sulphur 67,100 Sulphur dioxide 67 Supersonic flow (cutting gas) 139-144 Support of workpiece 144-146 Surface coating for absorption 84-85 Surface damage of workpiece 158, 159 Surface finish of workpiece

aluminium 84-85 mild steel 40-44

Surface roughening 85 Surface tension (of melt) 40, 84 Symmetric stretch mode (C02) 190

Targets (alignment) 121, 122, 124, 151 Teak (see also Wood) 109 TEM (transverse electromagnetic mode)

nomenclature 18, 197-200 TEMoo, see Mode, Gaussian (also TEM

nomenclature) TEMolo, see Mode, doughnut (also TEM

nomenclature) Temperatures of cut front 99, 223-224 Tempering (steel) 68 Temporal coherence 196 Termination of cut 34-36 Theoretical analysis of cutting 205-229 Thermal conductivity

generalS, 6, 7, 72,101,219 aluminium 82, 83 copper 88, 89 losses from cut zone 206-210, 215-217 non-ferrous metals 72

Thermal distortion 3, 94 Thermal gradient 217 Thermal lensing 40,147, 163 Thermal shock 114 Thermoplastics 91-108, 223-224 Thermoset plastics 7, 93, 98-99, 223-224 Thickness, maximum 50, 106, 209-210, 216 Three-dimensional work 145 Titanium alloys

general 4, 39, 71, 72, 74-81 inert gas cutting 76-81 mechanical properties 76

248

mechanisms of cutting 75-76, 77-81 metallurgy 76 oxygen cutting 75-76 quality of cut 77-81 speed of cutting 75, 77

Titanium carbide 111 Titanium nitride 111 Tool steels 65-66, 67-70 Toxic limits (fumes) 169-171 Training 166-167 Transmitted losses 206-209, 217-222 Transverse electromagnetic mode, see TEM Trials. cutting 103, 105, 115 Trimming of pressings 81 Troubleshooting 153-164 Tufnol99 Tungsten carbide 111 Tuning the laser 147-152 Turbulence 84

Units of measurement xvii Unstable cavity (unstable resonator) 19,20,

203 Upper lasing level 191

Vacuum pump 163 Vaporisation 31, 86, 91, 92, 96-98, 129 Vibrational energies 190-196

Vibrational quanta 190 Vices 146 Vortex ring 142-143 Vulcanisation 100

Warm up times 154

Index

Water cooling (of workpiece) 39, 43, 70, 83 Water jet cutting 179-184 Water vapour 92 Wavelength 9, 10, 192 Welding 20, 63, 77, 85,174,190 Width of cut, see Kerf width Wood (see also Plywood)

general 7, 92, 103, 108-111, 130 density: cut speed 108-109 efficiency of cutting 223-224, 226-227 quality of cut 10S-109 speed of cutting 109-111

Workpiece cooling 39, 43, 70, 83 Wrapping on polymers 97

YAG, see Nd:YAG

ZinC/zinc oxide 88,169,170 Zinc coated mild steel 41, 42-43, 169 Zinc fumes 43 Zinc selenide (ZnSe) 6, 160 Zintec, see zinc coated mild steel