LECTURE PRESENTATION
Reading Assignment
- FTD Chapter 2
Related Links
- The Tool Steel Guide
- Balancing wear, strength, and toughness; tips for choosing tool steels
- Tool Materials: ASM Specialty Handbook
- TMEH Volume 3: Materials, Finishes, and Coatings
- Tips for choosing tool steels, heat treatment, and surface treatments
- Bohler Cold Work Tool Steels (with datasheets)
- Coatings for Cutting Tools
- Mid South Tool Supply
Prerequisite Course Material
- 1711 -Manufacturing Processes I
- 3421 – Manufacturing Processes II
Outline
Physical Properties
- Weight
- Color
- Thermal and Electrical Conductivity
- Coefficient of Thermal Expansion
- Melting Point
Mechanical Properties
Strength
- Tensile Strength
- Compressive Strength
- Shear Strength
- Yield Strength
Hardness
- Rockwell
- Brinell
Wear Resistance/Resistance to Galling
Galling is adhesive wear or cold welding of one material to another that is sliding across it.
Especially a problem with austenitic stainless steels and aluminum.
Factors affecting Galling
Especially a problem with austenitic stainless steels and aluminum.
Factors affecting Galling
- design (avoid small friction areas)
- applied load,
- contact area and degree of movement,
- lubrication,
- environment,
- material properties (surface finish, hardness and steel microstructure).
Toughness
- Brittleness
- Plasticity
- Ductility
- Malleability
Stiffness, Modulus of Elasticity
Ferrous Tooling Materials
Carbon Steel
Alloy Steel
Tool Steel
- W – Water Hardening
- O – Oil Hardening (O1)
- A – Air Hardening (A2)
- D – High-Carbon, High Cr Die Steels
- S – Shock Resisting (S7)
- H – Hot Work Die Steels
- T & M – HSS
- L – Low Alloy Tool Steels
- F – Finishing Steels
Powder Metallurgy
- Improved Cracking and Fatigue Resistance
- Better Dimensional Stability during Heat Treatment
- Small, uniform carbide structure
- Potential for Increased tool life
Cast Iron
Invar
- Iron-Nickel alloy
- Low Coef. of thermal expansion
Nonferrous Tool Materials
Aluminum
Magnesium
Bismuth & Low Temperature Alloys
- Field’s Metal
- Woods’ Metal
Heat Treating
- Hardening
- Quenching
- Normalizing
- Stress Relieving
- Annealing
- Tempering
- Case Hardening
Nonferrous Metals
- Precipitation Hardening
- Solution Heat Treating
- Artificial Aging
- Work Hardening
Carbides
- ISO Machining Groups
- P (blue) Steel, Cast Steel
- M (yellow) Steel, Cast steel, austenitic steels
- K (Red) Cast iron, hardened steel, nonferrous metals
- JIC Grades
- C1
- C2
- Etc. The higher the number, the harder.
Cermets (TiC and TiN) in a cobalt binder
Cermets
Ceramics
Polycrystalline Diamonds
Nonmetallic Tool Materials
Wood
- Hardboard
- Densified Woods
- Plywood
- Particleboard/MDF
Polymers and Composite Materials
- Plastics
- Epoxy Resins
- Rubber
- Urethane
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See also:
http://aluminium.matter.org.uk/content/html/eng/default.asp?catid=61&pageid=989848382
