Powder Metallurgy. Science, Technology. and Materials. Anish Upadhyaya. G S Upadhyaya. Department of Materials Science and Engineering

Transcription

1 Powder Metallurgy Science, Technology and Materials Anish Upadhyaya Associate Professor Department of Materials Science and Engineering Indian Institute of Technology Kanpur, India G S Upadhyaya Former Professor Department ofmaterials and Metallurgical Engineering Indian Institute of Technology Kanpur, India Foreword by Prof. Dr Ken-ichi Takagi, Tokyo City University, Tokyo

2 Contents Foreword Preface About the series v vii ix 1 INTRODUCTION Production and Characterisation of Powders Treatment of Powder Compaction of Powder Sintering Full Density Processing Secondary Treatment Applications Holistic View of PM Science and Technology 12 2 POWDER PRODUCTION Chemical Methods Solid-state reduction Hydro-metallurgical reduction Ion exchange method Direct synthesis Some specific powders produced by chemical method Electrolytic Method Some specific powders produced by electrolysis Atomisation Method Gas atomisation Water atomisation Liquid gas atomisation Centrifugal atomisation Vacuum atomisation Ultrasonic gas atomisation Chill methods Some specific atomised metal and alloy powders Evaporation Methods Mechanical Methods 64 3 POWDER CHARACTERISATION Powder Sampling Chemical Composition and Structure 80

3 xii Contents 3.3 Particle Size Sieving method Permeability method Light scattering method Sedimentation method Turbidimetry method Crystallite size measurement Particle Surface Topography Surface Area True, Apparent and Tap Density Flow Rate Compressibility Green Strength Pyrophoricity and Toxicity 93 4 POWDER TREATMENT Particle 99 Separation 4.2 Annealing and Diffusion Alloying Powder Mixing Lubricant additive Binder additive Equipments Granulation Coating on Metal Powders Electroplating Electroless deposition Coating by hydro-metallurgical process 4.6 Powder Degassing , POWDER COMPACTION Basic Aspects Powder packing Powder bed under load Type of material Die Compaction Pressing operation Compaction presses Press selection Factors affecting tooling design Tooling materials 132

4 Contents xiii Part classification Guidelines for part geometry Warm Compaction Wet Compaction Cold Isostatic Compaction Isostatic press equipment and pressing operation Powder Roll Compaction Powder Extrusion Injection Moulding PIM part design Green Part Material Handling PRESSURELESS POWDER SHAPING Slip Casting/Slurry Moulding Viscosity of a slurry Drying Tape Casting Electrophoretic Deposition Spray Deposition/Forming Solid Freeform Fabrication SINTERING THEORY Solid-state Sintering: Pressureless Analytical approach to sintering: Stages in sintering Non-isothermal sintering Microstructural evolution Numerical simulation of sintering Phenomenological approach to sintering Sintering maps or diagrams Sintering of nanopowders Solid-state sintering of premixed/pre-alloyed powders Liquid Phase Sintering Stages of liquid phase sintering Wetting aspects of liquid phase sintering Microstructural evolution during liquid phase sintering Supersolidus sintering Activated Sintering Pressure-assisted Sintering Plastic yielding mechanism Creep mechanisms 210

5 xiv Contents Viscous flow mechanism Electronic Theory of Sintering: A Unified Approach Liquid phase sintering Activated sintering Case study: Sintering of refractory compounds SINTERING TECHNOLOGY Debinding Loose Sintering Sintering Furnaces Batch-type furnace Continuous furnace Vacuum furnace Electric furnace heating elements Furnace connectivity and control Sintering Zones Burn-off and entrance zone High-temperature zone Cooling zone Rapid Sintering Processes Induction sintering Microwave sintering Sintering Atmosphere Hydrogen Reformed hydrocarbon gases Nitrogen and nitrogen-based atmospheres Dissociated ammonia Argon and helium Vacuum Sintering Atmosphere Analysis and Control Gas analysis Specific gravity analysis Moisture determination Carbon potential control Process Variables Material Variables Dimensional Changes Microstructural Changes Infiltration Sintered Parts Material Handling 265

6 Contents xv 9 FULL DENSITY CONSOLIDATION Dynamic Powder Compaction Hot Pressing Process and equipment Hot Isostatic Pressing (HIP) Equipment and process variables Sinter-HIP or overpressure sintering Powder Hot Extrusion Process Powder Hot Forging Preform manufacturing and forging Hot Rolling of PM Preforms Spark Sintering SECONDARY TREATMENTS Sizing and Coining Machining Machining practice Impregnation Surface Engineering Steam treatment Coating Shotpeening Heat Treatment Hardening and tempering Case hardening Age hardening Joining TESTING AND QUALITY CONTROL OF PM MATERIALS AND PRODUCTS Sampling Density Sintered Porosity and Pore Distribution Structure of PM Materials Qualitative metallography and ceramography Quantitative metallography X-ray analysis Differential Thermal Analysis Thermal Expansion Thermal Shock Resistance 338

7 xvi Contents I 1.8 Thermal Conductivity Optical Properties Roughness Hardness Brinell hardness test Vickers hardness test Rockwell hardness test Microhardness test Strength 343! Tensile strength Compressive strength Transverse rupture strength (Bending strength) Modulus of elasticity Effect of grain size and dispersed hard particles Impact Test Fracture Toughness Fatigue Behaviour Creep Behaviour Fracture Behaviour Wear Resistance Machinabilty Electrical Resistivity Magnetic Properties Corrosion Resistance Quality Control of PM Parts Filters Porous bearings Structural parts Cemented carbide cutting tools Non-destructive Testing Statistical Quality Control METALLIC AND CERAMIC PM MATERIALS Low-alloy Ferrous Materials Fe-C alloys Copper-and nickel-containing steels Manganese- and chromium-containing steels Phosphorus-containing alloys High-alloy Steels High-speed steels Stainless steels 386

8 Contents xvii 12.3 Copper Alloys Aluminium Alloys Silver Alloys Nickel Alloys Titanium Alloys Refractory Metals Copper-containing alloys Precipitation/Dispersion-strengthened refractory metals Tungsten heavy alloys Tantalum Intermetallics Silicides Aluminides Rare earth intermetallics Ceramic Systems Porcelain (Whiteware) Alumina, magnesia and zirconia Barium titanate Ferrites Oxide superconductors Oxide nuclear fuels Silicon carbide Silicon nitride Refractory compounds Cermets Oxide-based cermets Non-oxide-based cermets including cemented carbides Ceramic-Ceramic Composites Sintered Nanocrystalline Metals and Ceramics Functionally Graded Materials MPIF PM Material Code APPLICATIONS OF PM PRODUCTS Structural Applications Automotive applications Aerospace applications Ordnance applications Machine Tools Cutting applications Non-cutting applications Power Generation 459

9 xviii Contents Applications based on fossil fuels Applications based on nuclear fuels Fuel cells Porous PM Products Friction Elements Electrical Materials Electrical contact materials Electric lamps Dielectrics Capacitors Magnetic Materials Soft magnetic materials Hard magnetic materials Oxygen Sensor Thermal Management Materials Hardfacing Rods Metal Foams Bio-implants TECHNO-ECONOMICS OF PM PROCESSING Cost of Metal and Ceramic Powders Techno-economics of Metal Powder Production Pyro-metallurgical methods Hydro-metallurgical methods Electrolytic methods Melt atomisation Mechanical milling Techno-economic Aspects of Sintered Parts Energy Saving in Powder Metallurgy Techno-economic Aspects of Full Density Consolidation Techno-economic Aspects of Powder Injection Moulding Techno-economic Aspects of Secondary Treatments Recycling of PM Materials Strategy for PM Part Business 501 Index 509