UTS ENGINEERING
41053
Materials & Manufacturing Engineering A
Material Properties, Testing & Manufacturing Processes
Bachelor of Engineering (Honours) | Year 1
University of Technology Sydney
, Topic 1: Material Properties
1.1 Mechanical Properties
Strength: Ability to withstand applied stress without failure
Stiffness: Resistance to elastic deformation (E = Young's modulus)
Toughness: Energy absorbed before fracture (area under stress-strain curve)
Hardness: Resistance to surface indentation (Brinell, Rockwell, Vickers)
Ductility: Ability to deform plastically before fracture (% elongation)
Brittleness: Fractures with little or no plastic deformation (glass, ceramics)
Fatigue strength: Maximum stress sustainable under cyclic loading
Creep: Slow deformation under constant stress at high temperature
1.2 The Stress-Strain Curve
Key regions of a tensile test (for ductile metal):
1. Elastic region — linear, reversible. E = σ/ε
2. Yield point — onset of plastic deformation. Stress = σᵧ
3. Strain hardening — material strengthens as it deforms
4. Necking — cross-section reduces locally
5. Fracture — failure
⚡ Exam Tip: The area under the entire stress-strain curve = toughness. The slope of elastic region = E
(stiffness).
Topic 2: Metal Alloys
2.1 Steel
Iron-carbon alloy (typically 0.02 – 2.14% C). Carbon content strongly affects properties:
• Low carbon (<0.3%): soft, ductile, weldable — structural steel, car bodies
• Medium carbon (0.3-0.6%): stronger, less ductile — gears, shafts, rail
• High carbon (0.6-1.4%): hard, brittle — cutting tools, springs, wire
Alloying elements:
• Chromium (Cr): stainless steel (≥11%), corrosion resistance
• Nickel (Ni): toughness and corrosion resistance
• Manganese (Mn): hardenability
• Molybdenum (Mo): high-temperature strength
41053
Materials & Manufacturing Engineering A
Material Properties, Testing & Manufacturing Processes
Bachelor of Engineering (Honours) | Year 1
University of Technology Sydney
, Topic 1: Material Properties
1.1 Mechanical Properties
Strength: Ability to withstand applied stress without failure
Stiffness: Resistance to elastic deformation (E = Young's modulus)
Toughness: Energy absorbed before fracture (area under stress-strain curve)
Hardness: Resistance to surface indentation (Brinell, Rockwell, Vickers)
Ductility: Ability to deform plastically before fracture (% elongation)
Brittleness: Fractures with little or no plastic deformation (glass, ceramics)
Fatigue strength: Maximum stress sustainable under cyclic loading
Creep: Slow deformation under constant stress at high temperature
1.2 The Stress-Strain Curve
Key regions of a tensile test (for ductile metal):
1. Elastic region — linear, reversible. E = σ/ε
2. Yield point — onset of plastic deformation. Stress = σᵧ
3. Strain hardening — material strengthens as it deforms
4. Necking — cross-section reduces locally
5. Fracture — failure
⚡ Exam Tip: The area under the entire stress-strain curve = toughness. The slope of elastic region = E
(stiffness).
Topic 2: Metal Alloys
2.1 Steel
Iron-carbon alloy (typically 0.02 – 2.14% C). Carbon content strongly affects properties:
• Low carbon (<0.3%): soft, ductile, weldable — structural steel, car bodies
• Medium carbon (0.3-0.6%): stronger, less ductile — gears, shafts, rail
• High carbon (0.6-1.4%): hard, brittle — cutting tools, springs, wire
Alloying elements:
• Chromium (Cr): stainless steel (≥11%), corrosion resistance
• Nickel (Ni): toughness and corrosion resistance
• Manganese (Mn): hardenability
• Molybdenum (Mo): high-temperature strength
