# Materials Cheat-Sheet

[^note]:
    Original data taken from
    [_Engineering Materials 1_](https://www.sciencedirect.com/book/9780080966656/engineering-materials-1)
    and expanded with [Claude](https://claude.ai).

- [Metals and alloys](#metals)
  - Iron and steels
  - Aluminum and alloys
  - Copper and alloys
  - Nickel and alloys
  - Titanium and alloys
- [Polymers](#polymers)
  - Polyethylene (PE)
  - Polymethylmethacrylate (acrylic and PMMA)
  - Nylon or polyamide (PA)
  - Polystyrene (PS)
  - Polyurethane (PU)
  - Polyvinylchloride (PVC)
  - Polyethylene terephthalate (PET)
  - Polyethylether ketone (PEEK)
  - Epoxies (EP)
  - Elastomers, such as natural rubber (NR)
- [Ceramics and glasses](#ceramics)
  - Alumina (Al2O3, emery, sapphire)
  - Magnesia (MgO)
  - Silica (SiO2) glasses and silicates
  - Silicon carbide (SiC)
  - Silicon nitride (Si3N4)
  - Cement and concrete
- [Composites](#composites)
  - Fiberglass (GFRP)
  - Carbon-fiber reinforced polymers (CFRP)
  - Kevlar-fiber reinforced polymers (KFRP)
  - Filled polymers
  - Cermets
- [Natural materials](#natural)
  - Wood
  - Leather
  - Cotton/wool/silk
  - Bone
  - Rock/stone/chalk
  - Flint/sand/aggregate

## Metals and Alloys {metals}

### Iron and Steels

- **Chemical composition:** Base is Fe (iron) with C (carbon) content
  determining type:
  - **Cast iron:** 2.1-4% C, brittle but excellent for casting
  - **Carbon steel:** 0.05-2.1% C, balance between strength and ductility
  - **Stainless steel:** Min 10.5% Cr for corrosion resistance, often includes
    Ni and Mo
- **Common alloying elements and their effects:**
  - **Chromium (Cr):** Corrosion resistance, hardenability
  - **Nickel (Ni):** Ductility, toughness, corrosion resistance
  - **Molybdenum (Mo):** Strength at high temperatures, corrosion resistance
  - **Manganese (Mn):** Hardenability, deoxidation
- **Product examples:**
  - **Cast iron:** Engine blocks, cookware, pipes
  - **Carbon steel:** Construction beams (A36), tools, automotive parts
  - **Stainless steel:** 304 (kitchen equipment), 316L (marine applications),
    420 (knives)

### Aluminum and Alloys

- **Chemical composition:** Base Al with various alloying elements
- **Major alloy series:**
  - **1xxx:** Pure Al (99%+), excellent corrosion resistance
  - **2xxx:** Al-Cu alloys, high strength (aircraft grade)
  - **3xxx:** Al-Mn alloys, good formability
  - **5xxx:** Al-Mg alloys, marine grade
  - **6xxx:** Al-Mg-Si alloys, good extrudability
  - **7xxx:** Al-Zn alloys, highest strength
- **Product examples:**
  - **2024:** Aircraft structures
  - **6061:** General purpose structural (bikes, boats)
  - **5052:** Marine applications
  - **3003:** Food packaging

### Copper and Alloys

- **Major alloy types:**
  - **Brass (Cu-Zn):** 5-45% Zn
  - **Bronze (Cu-Sn):** typically 12% Sn
  - **Beryllium copper:** 2% Be, highest strength copper alloy
- **Properties:**
  - Excellent electrical conductivity (pure Cu)
  - Superior thermal conductivity
  - Good corrosion resistance
  - Antimicrobial properties
- **Product examples:**
  - **Pure copper:** Electrical wiring, plumbing tubes
  - **Brass:** Musical instruments, decorative hardware
  - **Bronze:** Bearings, sculptures
  - **Beryllium copper:** Springs, non-sparking tools

### Nickel and Alloys

- **Major types:**
  - **Pure nickel:** Excellent corrosion resistance
  - **Monel (Ni-Cu):** Superior seawater resistance
  - **Inconel (Ni-Cr-Fe):** High-temperature strength
  - **Nichrome (Ni-Cr):** Heating elements
- **Key properties:**
  - High-temperature strength
  - Excellent corrosion resistance
  - Good mechanical properties
- **Product examples:**
  - **Inconel 718:** Jet engines, gas turbines
  - **Monel 400:** Chemical processing equipment
  - **Nichrome:** Electric heaters
  - **Pure nickel:** Electronics plating

### Titanium and Alloys

- **Major alloy types:**
  - **Pure Ti (Grade 1-4):** Varying oxygen content
  - **Ti-6Al-4V (Grade 5):** Most common alloy
  - **Ti-3Al-2.5V:** For seamless tubing
- **Properties:**
  - Highest strength-to-weight ratio
  - Excellent corrosion resistance
  - Biocompatibility
  - High cost
- **Product examples:**
  - **Pure Ti:** Medical implants, chemical processing
  - **Ti-6Al-4V:** Aerospace components, sports equipment
  - **Ti-3Al-2.5V:** Bicycle frames, hydraulic tubing
  - **Beta titanium:** Springs, orthopedic implants

## Polymers {polymers}

### Polyethylene (PE)

- **Chemistry:** (-CH2-CH2-)n, made from ethylene monomer
- **Types by density:**
  - **LDPE (Low Density):** Highly branched chains, 0.91-0.94 g/cm³
  - **HDPE (High Density):** Linear chains, 0.94-0.97 g/cm³
  - **UHMWPE (Ultra-High Molecular Weight):** Extremely long chains
- **Properties:**
  - Chemical resistance
  - Moisture barrier
  - Flexible to rigid depending on type
- **Products:**
  - **LDPE:** Food wrap, plastic bags
  - **HDPE:** Milk jugs, pipes
  - **UHMWPE:** Artificial joints, bulletproof vests

### Polymethylmethacrylate (PMMA)

- **Chemistry:** \[-CH2-C(CH3)(COOCH3)-\]n
- **Properties:**
  - Outstanding optical clarity (92% light transmission)
  - UV resistant
  - Scratch resistant compared to other plastics
  - Brittle but high impact versions available
- **Products:**
  - Aircraft windows
  - LED light guides
  - Dentures
  - Display stands
  - Contact lenses

### Nylon/Polyamide (PA)

- **Chemistry:** Contains amide groups (-CO-NH-)
- **Common types:**
  - **PA 6:** Made from caprolactam
  - **PA 66:** Made from hexamethylenediamine and adipic acid
- **Properties:**
  - High tensile strength
  - Good abrasion resistance
  - Low friction coefficient
  - Moisture sensitive
- **Products:**
  - Clothing fibers
  - Gears and bearings
  - Fishing line
  - Rope
  - Cable ties

### Polystyrene (PS)

- **Chemistry:** (-CH2-CH(C6H5)-)n
- **Types:**
  - **General Purpose PS (GPPS):** Clear, brittle
  - **High Impact PS (HIPS):** Modified with rubber
  - **Expanded PS (EPS):** Foam structure
- **Properties:**
  - Rigid
  - Good electrical insulation
  - Poor chemical resistance
- **Products:**
  - Food packaging
  - Disposable cutlery
  - CD cases
  - Insulation foam

### Polyurethane (PU)

- **Chemistry:** Contains urethane links (-NH-CO-O-)
- **Types:**
  - Flexible foams
  - Rigid foams
  - Elastomers
  - Coatings
- **Properties:**
  - Versatile mechanical properties
  - Good abrasion resistance
  - Weather resistant
- **Products:**
  - Foam mattresses
  - Car seats
  - Shoe soles
  - Building insulation
  - Coatings and varnishes

### Polyvinylchloride (PVC)

- **Chemistry:** (-CH2-CHCl-)n
- **Types:**
  - Rigid PVC (uPVC)
  - Flexible PVC (with plasticizers)
- **Properties:**
  - Fire resistant
  - Chemical resistant
  - Weather resistant
  - Good electrical insulation
- **Products:**
  - Pipes and fittings
  - Window frames
  - Wire insulation
  - Medical tubing
  - Credit cards

### Polyethylene terephthalate (PET)

- **Chemistry:** (-O-CO-C6H4-CO-O-CH2-CH2-)n
- **Properties:**
  - High strength
  - Excellent barrier properties
  - Good chemical resistance
  - Recyclable
- **Products:**
  - Beverage bottles
  - Food containers
  - Polyester fibers
  - Strapping tape
  - Film for packaging

### Polyether ether ketone (PEEK)

- **Chemistry:** Contains aromatic rings linked by ether and ketone groups
- **Properties:**
  - Very high temperature resistance (up to 260°C)
  - Excellent chemical resistance
  - High strength and stiffness
  - Biocompatible
- **Products:**
  - Aircraft components
  - Medical implants
  - High-performance bearings
  - Semiconductor equipment

### Epoxies (EP)

- **Chemistry:** Contains epoxide groups, typically cured with amines
- **Types:**
  - Two-part systems
  - One-part heat-cured systems
- **Properties:**
  - Excellent adhesion
  - High strength
  - Chemical resistant
  - Low shrinkage
- **Products:**
  - Adhesives
  - Coatings
  - Circuit board substrates
  - Composite matrices

### Elastomers/Natural Rubber (NR)

- **Chemistry:** Polyisoprene (C5H8)n
- **Types:**
  - Natural rubber
  - Synthetic rubbers (SBR, NBR, EPDM)
- **Properties:**
  - High elasticity
  - Good tear resistance
  - Abrasion resistant
  - Temperature sensitive
- **Products:**
  - Tires
  - Seals and gaskets
  - Elastic bands
  - Shoe soles
  - Gloves

## Ceramics and Glasses {ceramics}

### Alumina (Al2O3)

- **Crystal structure:**
  - Hexagonal close-packed oxygen ions with Al³⁺ in octahedral sites
  - Multiple phases (α, γ, θ) with α being most stable
- **Forms:**
  - **Corundum:** Natural crystalline form
  - **Sapphire:** Single crystal (blue with Ti/Fe impurities)
  - **Ruby:** Red variety with Cr impurities
- **Properties:**
  - High hardness (9 on Mohs scale)
  - High temperature resistance (melting point 2072°C)
  - Excellent electrical insulation
  - Chemical inertness
- **Products:**
  - Abrasives and cutting tools
  - Semiconductor substrates
  - Watch crystals
  - High-temperature crucibles
  - Spark plug insulators

### Magnesia (MgO)

- **Chemistry:**
  - Ionic compound with cubic crystal structure
  - Produced by calcining magnesite (MgCO3)
- **Properties:**
  - High refractoriness (melting point 2852°C)
  - Basic oxide character
  - Good thermal conductivity
  - Electrical insulation
- **Applications:**
  - Refractory furnace linings
  - Electrical insulators
  - Cement additives
  - Animal feed supplement
  - Antacid medications

### Silica (SiO2) Glasses and Silicates

- **Forms:**
  - **Crystalline:** Quartz, cristobalite, tridymite
  - **Amorphous:** Various glasses
- **Glass types:**
  - Soda-lime glass (72% SiO2, Na2O, CaO)
  - Borosilicate glass (80% SiO2, B2O3)
  - Fused silica (100% SiO2)
- **Properties:**
  - Transparent to visible light
  - Chemical durability
  - Thermal shock resistance (varies by type)
  - Electrical insulation
- **Products:**
  - Windows and containers
  - Laboratory glassware
  - Optical fibers
  - Telescope mirrors
  - Electronic substrates

### Silicon Carbide (SiC)

- **Structure:**
  - Many polytypes (3C, 4H, 6H most common)
  - Strong covalent bonding
- **Properties:**
  - Extreme hardness (9.5 Mohs)
  - High thermal conductivity
  - Low thermal expansion
  - Semiconductor behavior
- **Applications:**
  - Abrasives and cutting tools
  - High-temperature bearings
  - Power electronics
  - Armor materials
  - Heating elements

### Silicon Nitride (Si3N4)

- **Structure:**
  - Two main crystalline forms (α and β)
  - Complex 3D network of SiN4 tetrahedra
- **Properties:**
  - High strength and toughness
  - Low thermal expansion
  - Good thermal shock resistance
  - Excellent wear resistance
- **Applications:**
  - Cutting tools
  - Engine components
  - Bearings
  - Turbocharger rotors
  - Metal forming dies

### Cement and Concrete

- **Chemistry:**
  - **Portland cement:** Ca silicates and aluminates
  - Complex hydration reactions during setting
- **Types:**
  - Ordinary Portland Cement (OPC)
  - Rapid-hardening cement
  - Sulfate-resistant cement
  - White cement
- **Properties:**
  - High compressive strength
  - Low tensile strength
  - Durability
  - Fire resistance
- **Applications:**
  - Building foundations
  - Bridges and dams
  - Roads and pavements
  - Precast components
  - Decorative elements

## Composites {composites}

### Fiberglass (GFRP - Glass Fiber Reinforced Polymer)

- **Structure:**
  - Glass fiber reinforcement (E-glass, S-glass, or specialty)
  - Polymer matrix (typically polyester, epoxy, or vinyl ester)
  - Fiber content typically 30-60% by volume
- **Properties:**
  - Good strength-to-weight ratio
  - Corrosion resistant
  - Electrically insulating
  - Moderate cost
  - Good formability
- **Manufacturing methods:**
  - Pultrusion
  - Hand lay-up
  - Spray-up
  - Filament winding
  - RTM (Resin Transfer Molding)
- **Products:**
  - Boat hulls
  - Storage tanks
  - Wind turbine blades
  - Automotive panels
  - Construction panels

### Carbon-fiber Reinforced Polymers (CFRP)

- **Fiber types:**
  - High strength (HS)
  - High modulus (HM)
  - Ultra-high modulus (UHM)
- **Matrix materials:**
  - Epoxy (most common)
  - PEEK (high performance)
  - Bismaleimide (high temperature)
- **Properties:**
  - Exceptional strength-to-weight ratio
  - High stiffness
  - Low thermal expansion
  - Fatigue resistant
  - Expensive
- **Applications:**
  - Aerospace structures
  - Sports equipment
  - High-end automotive
  - Racing vehicles
  - Industrial robotics

### Kevlar-fiber Reinforced Polymers (KFRP)

- **Fiber characteristics:**
  - Para-aramid fibers
  - High tensile strength
  - Low density
  - Excellent impact resistance
- **Properties:**
  - Superior impact resistance
  - Good vibration damping
  - High tensile strength
  - Low compressive strength
  - UV sensitive
- **Applications:**
  - Ballistic protection
  - Motorcycle clothing
  - Sports equipment
  - Aircraft components
  - Marine cordage

### Filled Polymers

- **Common fillers:**
  - Mineral fillers (calcium carbonate, talc)
  - Carbon black
  - Glass beads
  - Wood flour
  - Nanofillers (clay, carbon nanotubes)
- **Benefits:**
  - Cost reduction
  - Improved mechanical properties
  - Better dimensional stability
  - Enhanced flame retardancy
  - Modified electrical properties
- **Applications:**
  - Automotive parts
  - Construction materials
  - Electronic housings
  - Consumer products
  - Industrial components

### Cermets

- **Structure:**
  - Ceramic particles in metal matrix
  - **Common combinations:**
    - WC-Co (tungsten carbide-cobalt)
    - TiC-Ni (titanium carbide-nickel)
    - Al2O3-Al (alumina-aluminum)
- **Properties:**
  - High hardness
  - Good toughness
  - Wear resistance
  - Temperature resistance
  - Chemical stability
- **Applications:**
  - Cutting tools
  - Mining equipment
  - Metal forming dies
  - Wear components
  - Aerospace parts

## Natural Materials {natural}

### Wood

- **Structure:**
  - Cellulose fibers (40-50%)
  - Hemicellulose (25-35%)
  - Lignin (20-35%)
  - Growth rings and grain patterns
- **Types:**
  - Hardwoods (oak, maple, walnut)
  - Softwoods (pine, cedar, spruce)
  - Engineered wood (plywood, MDF, OSB)
- **Properties:**
  - Anisotropic strength
  - Good strength-to-weight ratio
  - Natural thermal insulation
  - Hygroscopic (moisture-sensitive)
  - Biodegradable
- **Applications:**
  - Construction
  - Furniture
  - Paper products
  - Fuel
  - Decorative items

### Leather

- **Structure:**
  - Collagen fiber network
  - **Three layers:** grain, corium, flesh
- **Processing:**
  - Tanning (chrome, vegetable, synthetic)
  - Dying and finishing
  - Surface treatments
- **Properties:**
  - High tensile strength
  - Good abrasion resistance
  - Breathable
  - Ages aesthetically
  - Moldable
- **Applications:**
  - Footwear
  - Clothing
  - Upholstery
  - Accessories
  - Book binding

### Cotton:

- **Structure:** Cellulose fibers
- **Properties:**
  - Highly absorbent
  - Comfortable
  - Good tensile strength
  - Biodegradable

### Wool:

- **Structure:** Keratin protein fibers
- **Properties:**
  - Natural insulation
  - Moisture-wicking
  - Fire-resistant
  - Elastic recovery

### Silk:

- **Structure:** Protein fibroin fibers
- **Properties:**
  - High tensile strength
  - Smooth texture
  - Good drape
  - Temperature regulating

### Bone

- **Composition:**
  - Hydroxyapatite (mineral phase)
  - Collagen (organic phase)
  - Water
- **Structure:**
  - Cortical (dense outer layer)
  - Cancellous (porous interior)
- **Properties:**
  - High compressive strength
  - Good toughness
  - Self-healing capability
  - Anisotropic behavior
- **Applications:**
  - Medical implants
  - Fertilizer
  - Traditional tools
  - Decorative items

### Rock:

- **Types:**
  - Igneous (granite, basalt)
  - Sedimentary (limestone, sandstone)
  - Metamorphic (marble, slate)
- **Properties:**
  - High compressive strength
  - Weather resistant
  - Low maintenance
  - Thermal mass

### Stone:

- **Processing:**
  - Cut
  - Polished
  - Split
  - Crushed
- **Applications:**
  - Building materials
  - Countertops
  - Sculptures
  - Landscaping

### Chalk:

- **Composition:** Calcium carbonate
- **Properties:**
  - Soft
  - Porous
  - Water-soluble
  - Good marking ability

### Flint:

- **Composition:** Cryptocrystalline silica
- **Properties:**
  - Very hard
  - Conchoidal fracture
  - Sharp edges when broken
  - Fire starting capability

### Sand:

- **Types:**
  - Silica sand
  - Mineral sands
  - Beach sand
- **Applications:**
  - Construction
  - Glass making
  - Foundry casting
  - Filtration

### Aggregate:

- **Types:**
  - Crushed stone
  - Gravel
  - Recycled concrete
- **Applications:**
  - Concrete
  - Road base
  - Drainage
  - Landscaping