Flashcards in Chapter 2 Deck (28):
Types of ferrous and nonferrous
Ferrous - Steel and cast iron
Nonferrous - aluminum and copper
Four types of steel
Plain carbon steel
Low alloy steel
Plain carbon steel. Explain strength and ductility.
Mainly carbon. Strength increases with carbon but ductility decreases. Heat treated will make martensite which is very strong and hard.
Plain carbon steel. Explain use of low, medium, and high carbon steel.
Low carbon (<0.20%) - railroad rails
Medium carbon (0.20% to 0.50%) - Machinery components.
High Carbon (>0.50%) - Springs, and cutting tools and blades
Low alloy steel
Superior to plain carbon steel after heat treatment. High strength, hardness, hot hardness,
15% Chromium. Nickel protects against corrosion. Carbon adds strength and hardness but reduces corrosion protection.
More expensive than low alloy and plain C.
Highly alloyed. Heat treated. For dies and molds.
Properties of Nickel and alloys
Magnetic. Modulus of E close to iron. Superior when heat treated. Very corrosive resistant.
Properties of Zinc and alloys
Low melting temp so for die casting. Corrosion protection as coating.
Properties of Superalloys
Resist surface degradation at high temperature. Very expensive. Gas turbines
Meant for 1100 C temp.
What are new Ceramics
Controlled simple structures.
oxides, carbides, nitrides, and borides.
Oxides ceramics. Properties
Al2O3 or Alumina.
Good hot hardness, low thermal conductivity, and good corrosive resistance
Silicon Carbide and tungsten carbide
Properties of Nitrides
Silicon nitride and boron nitride
Hard, brittle, high melting temperature, electrically insulating.
Gas turbine components and cutting tool coatings
State of matter - Not enough time to cool from molten state to crystalline structure.
Type of ceramic - Inorganic nonmetallic that cools to a rigid condition without crystallizing.
Main component of Glass
SiO2. Silica. 50% to 70%
Naturally transforms into a glassy state when cooling instead of crystallization like other ceramics.
Why add ingredients to glass
Adds color, acts as flux (promotes fusion), alter index of refraction for optics, and decreases viscosity
Polymer and properties
Organic long-chain molecules.
Low density. good strength to weight. high corrosion resistance. low electrical and thermal conductivity.
Types of Polymers
Plastics - thermosetting and thermoplastic
Rubber - elastomers
Polyethylene and nylon. Solid at ambient temp but liquid at ~100 degrees. No degradation after cycles of cooling and heating.
Phenolics and epoxies. Degrades (char) after repeated heating cycles. When heated they flow and shape around mold. Elevated temp cause chemical reaction making it in-fusible.
Rubbers. Extreme elastic extensibility (factor of 10) under relatively low mechanical stress.
Similar structures to thermosets but different properties. Both different to thermoplastics.
Importance of Polymers. 4 traits.
Net shape processing.
Require less energy to produce than metals.
Transparency competes with glass.
Name polymer molecular structure
Linear (chain link), Branched (chain link but with branches), cross-linked (elastomers are loose; thermosets are tight)
Very strong and stiff yet light in weight.
Great fatigue properties
What are primary and secondary phases
Primary - The matrix when the secondary phase is embedded
Secondary - Reinforcing phase that reinforces the primary phase.
It strengthens the material which as a fibers, particles or flakes.