1. Powder Metallurgy Processing 1 Contents 1. Introduction of Powder Processing 2. Synthesis and Production 3. Mixing 4. Characterization Methods 5. Shaping and Compaction 6. Sintering 7. Applications

2. Powder Metallurgy Processing 2 1. Introduction of Powder Processing

3. Powder Metallurgy Processing 3 (1) powder : fluidlike substance (2) process : powder handling powder compaction in a rigid dies under pressure → densified by deformation ⇒ solid structure with weak bonding heated to a temp. where the particles sinter together ⇒ form strong bond Powder → Mixing and shaping → Pressing (Mechanical bonding) → Sintering (Thermal bonding) → grain growth and densification → Products Powder Process

4. Powder Metallurgy Processing 4 * Technological advantages (table 2.2) - microstructural control, material use, production homogeneity, mass production  P/M production range (tabel 2.3, Fig. 2.2) - moderately complex shape (15-1000 callouts on the engineering drawing) - higher production quantities - mass range of 1 - 1000g - moderate surface finish - metallic materials strength and mechanical properties Tensile strength of sintered products : 15~20kg/ ㎟ (1950-60)  > 50kg/ ㎟ (2000-) Larger products (0.1gr~ Kg scale), more wide application area Advantages and technical characteristics

5. Powder Metallurgy Processing 5 Example applications - mostly automobile components, ex) in ferrous powder, > 70% ○ Automotive : connecting rods, bearing cap, transmission gear, etc - US car : ∼ 15 ㎏ /ear ( ∼ 70% of ferrous powder) - Europe, Korean Japan : 7 ∼ 10 ㎏ /ear (>80% of ferrous) ○ Electrical, Magnetic : Welding electrode, tungsten filament, electrical contacts, hard magnets (Al-Ni-Co, Sn-Co, Nd-Fe-B, etc) soft magnets (iron, permalloy, cobalt base, etc) ○ Aerospace : Super-alloy for turbine disk(Rene 95, IN100, MERL76, Astroloy, etc), High strength Al alloys (7090, 7091, etc), P/M Titanium alloys, etc ○ Medical, Dental applications : porous orthopedic implants, Dental amalgam, etc ○ Military : kinetic energy projectile, missile component, etc ○ Porous filters, bearing, form metals, composites, etc Applications

6. Powder Metallurgy Processing 6 * Growth and Economic Trend - in N.A. : automobiles ∼ $1.5 billion advanced P/M ∼ $500 million - Ferrous ∼ 80%, the rest ∼ 20% ◇ new trend - emphasize full density processing (hot isostatic pressing, injection molding, powder rolling, hot forging, hot pressing) - jet engines, biomedical implants, batteries, electrical contacts Growth and Trends

7. Powder Metallurgy Processing 7 Benefits of powder processes Elimination or minimization of machining. Elimination or minimization of scrap losses. Maintains close dimensional tolerances. Accommodates a wide variety of alloy systems. Produces good surface finishes. Produces materials that can be heat-treated for increased strength or wear resistance. Provides controlled porosity for self-lubrication or filtration Facilitates the manufacture of complex or unique shapes which would be difficult or impossible to produce with other metalworking processes. Suited to moderate-to high-volume component production requirements. Offers long-term performance reliability in critical applications. Cost effective.

8. Powder Metallurgy Processing 8 Powder metallurgy becomes advantageous...

9. Powder Metallurgy Processing Energy Required per Unit Weight of Finished Product

10. Powder Metallurgy Processing Material Utilization for different processes

11. Powder Metallurgy Processing 11 Reduction Electolytic deposition Carbonyls (reaction formed) Comminution (pulverization) Microencapsulated powders Atomization Mechanical alloying Precipitation Machining very fine chips Vapor condensation Nanopowder manufacturing Particle sizes range from 0.1 to 1000 microns Characteristics include shape, size distribution, porosity, chemical purity, particle bulk and surface qualities Production methods include: Powder Production

12. Powder Metallurgy Processing 12 Particle shapes

13. Powder Metallurgy Processing 13 Powder metallurgy, Ingot metallurgy

14. Powder Metallurgy Processing 14 Powder Processes ELEMENTAL OR ALLOY METAL POWDERS ADDITIVES (DIE LUBRICANTS, GRAPHITE) ISOSTATIC, EXTRUSION, DIE COMPACTING, SPRAYING, SINTERING HOT COMPACTION ISOSTATIC, DIE COMPACTING, ROLLING, INJECTION, MOLDING, SLIP CASTING COLD COMPACTION VACUUM OR ATMOSPHERE SINTERING SIZING, REPRESSING, RESINTERING, FORGING, COINING, METAL INFINTRATION, OIL IMPREGNATION OPTIONAL MANUFACTURING STEP HEAT TREATING, TUMBLING, PLATING, MACHINING, STEAM TREATING, HOT ISOSTATIC PRESSING OPTIONAL FINISHING STEP FINISHED PRODUCT RAW MATERIALS FORMING MIXING

15. Powder Metallurgy Processing 15 Powder Processes

16. Powder Metallurgy Processing 16 FINISHED PRODUCTS P/M Process OPTIONAL OPERATIONS SINTERINGFORMINGMIXING RAW MATERIALS Elemental or Alloy Metal Powders Additives (graphite, die, lubricants) Mixing Isostatic Extrusion Die Compacting Spraying Pressureless- Sintering Die Compacting Isostatic Rolling Injection Molding Slip Casting Cold Compaction Hot Compaction Atmosphere Vacuum High Temperature Sintering Repressing Coning Sizing Repressing Forging Rerolling Metal Infiltration Optional Manufacturing Steps Machining Heat Treating Steam Treating Plastic Impregnation Plating Tumbling Oil Impregnation Shot Peening Optional Finishing Steps Finished Products

17. Powder Metallurgy Processing 17 Main steps in powder metallurgy

18. Powder Metallurgy Processing Secondary Operations  Repressing  Sizing  Coining  Machining  Forging  Heat treatment  Steam treatment  Impregnation  Infiltration  Plating  Tumbling Powder Processings

19. Powder Metallurgy Processing 19 Secondary powder metal processes