Material Science Flashcards
According to Miodownik, why did steel sword making acquire magic-like legend to it?
The process for incorporating the exact correct amount of steel was often complicated and not well understood, which was likened to magic
According to Miodownik, how did samurai swords incorporate different types of steel?
They used low carbon steel for the core to make them tough and high carbon steel for the edges to make them easy to sharpen.
What is polyester made out of?
Extruded petroleum
What is bronze made out of? Why was it so useful in early human development?
Bronze is a copper-tin alloy that is much harder than other available metals. It is easier to make than iron, which has a higher melting point
What is steel made out of?
Iron and carbon
What is stainless steel made out of?
Iron, carbon, and >10.5% chromium
How do you soften metal?
Warm it up
Why does metal make for better tools than bone, wood, or flint?
It is malleable and can be shaped without splintering, cracking, or breaking.
How do you make metal harder? What is that doing to the structure of the metal?
Hammering the metal. It creates a crystal structure between the atoms.
What property of the crystalline structure of metals allows them to be shaped and bent?
Dislocations are defects in the perfect crystal where atoms can move between parts of the crystal when bent
How did copper tools enable the Pyramids to be built?
They allowed the workers to carve and work on the blocks
Why do alloys tend to be stronger than pure metals?
The atoms are different sizes and disrupt the crystal structure. This makes it harder for dislocations to move.
What are the series of metal ages that humans went through?
Copper age, Bronze Age, Iron Age
What was the Bessemer process for making liquid steel? Why didn’t it work? How did they fix it?
Blow oxygen through the steel to take out carbon as carbon dioxide. It didn’t work because they couldn’t calibrate the amount of carbon. They fixed it by taking out all the carbon and adding back carbon
How does the chromium in stainless steel prevent rusting?
It reacts with the oxygen to form chromium oxide, which becomes a protective film over the steel
What is the name of the organic polymer that binds together cellulose in tree bark?
Lignin
What are some advantages of the book (codex) over the scroll?
- Faster to create and copy one page at a time
- Easier to search and index into as a reader
What do we add to paper to make it glossier, smoother, whiter, more water resistant, etc.?
Powder additives like calcium carbonate
How does concrete technically not dry out?
The water is actually locked up within the structure of the concrete. It forms a gel within the silicate hydrate fibrils.
What problem does reinforced concrete solve about concrete?
Concrete does well under compression but is susceptible to cracks and bending. The steel skeleton takes the stress there
How does self-healing concrete work?
They added bacteria found in alkali environments along with starch. When there’s a crack, the bacteria is exposed, rats, and produces calcite as waste to fill in.
What two properties make cocoa butter a good lotion?
Its low melting point makes it solid at room temperature but melt at body temperature. It has natural antioxidants for a long shelf life.
What about the structure of cocoa fat creates different types? How many types are there?
Cocoa butter is made of triglycerides, crystals that can pack in different ways to give different melting points and temperatures. There are 5 different types.
What is an aerogel?
A gel where the liquid component has been replaced by gas yet the gel structure remains
