Metals Flashcards
What are metals mined from?
Metals are mined from rocks on earth’s surface in raw form of ore, then extracted and processed through crushing, heating, and adding chemicals.
What are ferrous metals?
Ferrous metals are metals that contain iron, are magnetic, conduct heat and electricity, react with water, corrode, and have a higher melting point (1200°).
What is cast iron?
Cast iron is brittle, corrodes by rusting, and is used for casting, as a base metal for all steel alloys, manhole covers, and car brake discs.
What is stainless steel?
Stainless steel is hard, corrosion and water resistant, made of iron, nickel, magnesium, and chromium.
Used in various applications due to its resistance to rust.
What is high-speed steel (HSS)?
High-speed steel (HSS) is very brittle, strong, and resistant to wear, made of iron, tungsten, vanadium, and chromium.
What is mild steel?
Mild steel is tough, ductile, malleable, has good tensile strength, and poor resistance to corrosion.
Used for cutlery, kitchen equipment, sanitary and surgical equipment, drill bits, lathe tools, and general-purpose engineering.
What is high carbon steel?
High carbon steel is hard and tough, but increased carbon makes it brittle.
Used for cutting tools, ball bearings, hand tools, screwdrivers, hammers, chisels, and saws.
What are non-ferrous metals?
Non-ferrous metals are metals that do not contain iron and are not magnetic.
What is work hardening?
Work hardening is the process of continuously bending, hitting, or shaping a non-ferrous metal over time to strengthen it, making it more rigid and less likely to bend.
What is planishing?
Planishing is intentionally hitting copper with a planishing hammer, which hardens the copper with each strike after it’s been shaped.
What is annealing?
Annealing is heating metal to a specific temperature and cooling it, which changes the molecular structure to soften and make it workable.
The temperature required is indicated by color, e.g., red for mild steel.
What is tempering?
Tempering removes brittleness from hardened metal and makes it more usable by heating it to around 900° (turns red) and then plunging it into cold water.
What is case hardening?
Case hardening is a quicker method that hardens only the surface of mild steel to a depth of 0.05mm.
It involves heating mild steel to red color, dipping it into a hardening compound high in carbon, and then plunging it into cold water.
