Materials Science - Week 1
What are the three most common criteria when selecting materials?
1) Strength vs ductility 2) Deterioration 3) Cost
Why does the Boeing 787 claim tremendous fuel savings?
About 50% of its materials were composites, leading to the aircraft being lightweight and thus requiring less fuel.
Describe the purposes of advanced materials.
Biomaterials are inserted into the human body. Smart materials can sense changes in the material, use a sensor + actuator (ex. SMAs, piezoelectric ceramics) Nanomaterials are on the order of 10^-9 meters.
Why are aluminum and magnesium common for aerospace structures?
Both are metals with a low density, thus will have lower weight than if using another material.
Define a material property.
How a material responds to a stimulus.
Differentiate between materials science and materials engineering.
Materials science examines the relationship between structures and properties in a material. Materials engineering involves designed a structure to produce a predetermined set of properties.
What are the six types of properties we focus on? Give examples of each.
Mechanical (deformation from applied load), electrical ( conductivity), thermal (heat capacity, thermal conductivity), magnetic (magnetic field response), optical (index of refraction), and deteriorative (chemical reactivity).
Rank the three main types of materials from highest to lowest density.
Metals -> ceramics -> polymers
Name the types of materials.
Metals, ceramics, polymers, composites, advanced materials (bio/smart/nano-materials).
Differentiate between microscopic and macroscopic.
Microscopic - Can only be viewed with a microscope Macroscopic - Can be seen with the naked eye
Describe the general trend of properties for polymers.
Not stiff or strong, extremely ductile, decompose at modest temperatures. Low electrical conductivity.
Describe the general trend of properties for metals.
Stiff, strong, ductile, resistant to fracture. Good heat and electricity conductor, not transparent to visible light.
Describe the general trend of properties for ceramics.
Stiff, strong, hard, extremely brittle, easy to fracture. Good insulators.
Define material structure.
The arrangement of the internal composition of atoms.
Material performance is primarily a function of its __________.
properties
Microstructure/nanostructure of a material affects...
strength, ductility, toughness, and fatigue
Atomic structure of a material affects...
strength, stiffness
