Shigley's Mechanical Engineering Design Alloys Quiz

Material Properties

• Induction hardening or flame hardening: a process to harden the surface of a material.
• Alloy steels: contain elements like Chromium, Nickel, Manganese, Silicon, Molybdenum, Vanadium, and Tungsten.

Corrosion-Resistant Steels

• Stainless steels: Iron-base alloys with at least 12% chromium, resist many corrosive conditions.
• Four types of stainless steels: Ferritic chromium, Austenitic chromium-nickel, Martensitic, and Precipitation-hardenable.

Casting Materials

• Gray Cast Iron: a type of cast iron.
• Ductile and Nodular Cast Iron: types of cast iron.
• White Cast Iron: a type of cast iron.
• Malleable Cast Iron: a type of cast iron.
• Alloy Cast Iron: a type of cast iron.
• Cast Steel: a type of metal alloy.

Nonferrous Metals

• Aluminum: a nonferrous metal.
• Magnesium: a nonferrous metal.
• Titanium: a nonferrous metal.
• Copper-based alloys:
  • Brass: an alloy of copper and zinc.
  • Phosphor bronze: an alloy of copper, tin, and phosphorus.
  • Aluminum bronze: an alloy of copper and aluminum.

Plastics

• Thermoplastic: a plastic that flows or is moldable when heat is applied.
• Thermoset: a plastic for which the polymerization process is finished in a hot molding press.

Composite Materials

• Composite materials: formed from two or more dissimilar materials, each contributing to the final properties.
• Materials remain distinct from each other at the macroscopic level.
• Usually amorphous and non-isotropic.
• Common filler types: laminates of filler to provide stiffness and strength, and a matrix to hold the material together.

Material Families and Classes

• Material Families and Classes: Different materials grouped into families and classes based on their properties.

Young's Modulus

• Young's Modulus: a measure of the stiffness of a solid material.

Torsional Strengths

• Maximum shear stress: related to the angle of twist by a specific formula.
• Torsional yield strength: corresponds to the maximum shear stress at the point where the torque-twist diagram becomes significantly non-linear.
• Modulus of rupture: corresponds to the torque at the maximum point on the torque-twist diagram.

Resilience

• Resilience: the capacity of a material to absorb energy within its elastic range.
• Modulus of resilience: the energy absorbed per unit volume without permanent deformation.

Toughness

• Toughness: the capacity of a material to absorb energy without fracture.
• Modulus of toughness: the energy absorbed per unit volume without fracture.

Statistical Significance of Material Properties

• Material properties are distributional and thus statistical in nature.
• Histogram of probability density: a graph showing the number of occurrences of a specific material property.

Cold Work

• Cold work: the process of plastic straining below the recrystallization temperature in the plastic region of the stress-strain diagram.
• The yield point is effectively increased.
• Material is said to have been cold-worked, or strain-hardened.

Reduction in Area

• Reduction in area: a measure of ductility.
• Ductility: represents the ability of a material to absorb overloads and to be cold-worked.

Cold-work Factor

• Cold-work factor W: a measure of the quantity of cold work.

Hardness

• Hardness: the resistance of a material to penetration by a pointed tool.
• Rockwell and Brinell: two common hardness-measuring systems.

Strength and Hardness

• Relationship between ultimate strength and Brinell hardness number: approximately linear for many materials.

Impact Properties

• Impact properties: measured using the Charpy notched-bar test.
• Energy absorbed, called impact value, is computed from height of swing after fracture.