A2 - Engineering Materials Flashcards
(25 cards)
Why is material selection important in agri machines?
Because it directly affects durability, cost, and performance.
What’s the difference between ferrous and non-ferrous metals?
A: Ferrous = contains iron (e.g., steel, cast iron); Non-ferrous = no or little iron (e.g., aluminum, copper).
characteristics of cast iron
High compressive strength
high wearing resistance
low cost
low tensile strength
brittle
what is steel?
is cast into an ingot and then rolled, forged, hammered, pressed, or machine into desired shapes.
What are examples of non-metallic materials used in machines?
Plastics (for insulation)
rubber (for sealing)
wood (traditional parts)
ceramics (heat resistance)
fibers (ropes, insulation
glass (sight glasses, insulation)
What are standard machine parts and their uses?
Bearings → reduce friction
Pulleys → transmit power
Gears → speed/torque adjustment
Screws → fastening
Washers → load distribution
Why is material selection important in agricultural machinery?
It affects the machine’s durability, cost, and performance. Substandard materials lead to quick wear and higher power requirements.
What are the two main classifications of metals?
Ferrous (contains iron) and Non-Ferrous (does not contain iron in significant amounts).
Name examples of ferrous metals.
Cast iron, carbon steel, alloy steel.
Name examples of non-ferrous metals.
Aluminum, copper, magnesium, zinc.
What are the key properties of metals?
Hard, high melting temp, good conductivity, easily shaped, deformable without fracture.
What is cast iron best known for?
Good casting property, high compressive strength, and wear resistance, but it is brittle.
What is stainless steel made of and what are its properties?
1% Ni, 11–14% Cr, corrosion-resistant
What are thermoplastics and thermosetting plastics?
Thermoplastics can be remolded; thermosetting plastics become permanently hard after heating.
What is the function of bearings in machines?
They support and guide rotating parts, reducing friction between moving components.
engineering applications of rubber
shock, noise, and vibration control
sealing,
electrical and thermal insulations
waterproofing
What is steel?
cast into an ingot and then rolled, forged, hammered, pressed, or machined into desired shapes.
Soft-Centered Steel
durable to shock because the mild
steel in the center layer is deformable and is higher wear
resistant than hard steel at the outer side. They are usually
used for moldboard and share of a plow
Low-Carbon Steel
with carbon content not exceeding
0.25%
Medium-Carbon Steel
contains 0.25 to 0.50% carbon.
They are usually used in making structural and machinery
steel
High-Carbon Steel
carbon content is above 0.50%.
They are usually used in the manufacture of spring and tool
steel.
Mild Steel
contains carbon of 0.15 to 0.25%. They
are malleable and easy to cut and weld
Cold-Rolled Steel
are medium-carbon steel
which are used for components of machine requiring
greater strength and hardness, such as shafting and
connecting rods
Stainless Steel
1% Ni, 11-14% Cr, 0.6% Mn, 0.6%
Si. They have high resistance to corrosion and oxidation.
They are used for valves, nozzles, and dairy machines.
