Engineering Materials Flashcards
single element that is not combined with any other
chemical element. It is too soft, low in strength, or low in some
other desired property to be used in any commercial
Pure metal
mixture of two or more metals producing a new metal
Alloy
It is a pure ferrite.
Iron
produced from ore of hematite or magnetite in the blast furnace by melting with limestone and coke
Pig iron
with carbon content of 1.7 to 6/7%. It is low cost, good casting property, high compressive strength, high wearing resistance, brittle and lower tensile strength
Cast iron
- It is a molten iron with carbon added into it that is cast into
an ingot and then rolled, forged, hammered, pressed, or
machine into desired shape - Structural steel, steel bars and cylinders, and steel plates
are commonly used as machine elements and frames
Steel
durable to shock because the mild steel in the center layer is deformable and has higher wear
resistance than hard steel at the outer side. It is usually used for moldboard and share of a plow
Soft-centered steel
with carbon content not exceeding 0.25%
Low-carbon steel
contains 0.25 to 0.50% carbon. It is usually used in making structural and machinery steel.
Medium-carbon steel
carbon content is above 0.50%. It is usually used in the manufacture of spring and tool steel.
High-carbon steel
contains carbon of 0.15 to 0.25%. It is malleable and easy to cut and weld. Most parts of agricultural machines are made of this kind of metal.
Mild steel
a medium-carbon steel used for
components of machines requiring greater strength and hardness, such as axles for power tillers, hitch pin, spike tooth of threshers and shellers, connecting rods, etc
Cold-rolled steel
steel that has been roll-pressed at a very high temperature over 1,700°F which is above the re-crystallization temperature of steel. It is softer as compared to cold-rolled steel. It can be easily folded and rolled to form air ducts, chutes, etc
Hot-rolled steel
1% Ni, 11-14% Cr, 0.6% Mn, 0.6% Si. It has high resistance to corrosion and oxidation. It is used for fabrication of dairy, food, equipment. Standard materials such as valves, nozzles, and etc. are examples of the use of stainless steel
Stainless-steel
a steel manufactured under carefully controlled condition with carbon content between 1,7% to 1.5% commonly used as machine tool and other machine parts that require strength such as teeth for slow-moving shredders, special gears, pulley, etc
Tool steel
– steel that is processed by cold drawing, cold rolling, or heat treatment to give elastic property to the metal
Spring steel
a piece of metal which has been rolled into a sheet of 3/16in. or less in thickness. Commonly available sizes are 3’-wide x 6’-long and 4’-wide x 8’-long. The thickness is expressed
in terms of gauge number, which is equivalent to number of
sheets in 1in.-thick pile of metal sheet
Sheet
long sheets of metal that is less than 12in. Wide
Strips
metal with thickness over 3/16in. Commonly available
size is 4’-wide x 8’-long. Thickness is given in terms of mm or in inch
Plate
made of different shapes and are usually available in standard length of 20ft or 6m. They are purchased in terms of quantity, shape, size, and kind of metal used.
Metal bars
commonly used in the construction of agricultural machines. They are specified in terms of quantity wanted, the kind of material and shape, size, and length of each piece.
Structural shapes
include all hollow metal shapes such as pipes and tubes. They are available in round, square, and
rectangular shapes. Specifications are given in terms of shape,
schedule number, size, and length
Tubular products
Includes all metals such as copper, aluminum, magnesium, and zinc in which iron is not present in large amount.
Non-ferrous
- Large group of materials consisting of combination of carbon and oxygen, hydrogen, nitrogen, and other and organic elements - Non-metallic materials that can be molded into shape. They are light in weight, resistant to deterioration by moisture, low elasticity and thermal conductivity, and good color range.
Plastic
- Materials ranging from glass to furnace brick.
- These include ceramic oxides, glass-ceramics, carbides and
nitrides.
Engineering ceramics
- The oldest engineering material that includes jute, flax, and hemp
- Usually used for engineered products such as rope, cordage, nets, water hose, and containers. Plant and animal fibers are used for felt, paper, brushes, and heavy structural cloths
Fiber
- A non-crystalline or amorphous solid.
- Types include soda-lime glass, Borosilicate glass, lead-alkali
glass, aluminosilicate glass, silica glass, and fused silica.
Glass
- Standard parts of agricultural machines play a very important role in the construction and performance of the machine
- They are especially manufactured and mass produced to perform
a specific function. - They can be readily purchased from stores and hardware, and are available in various sizes.
Standard materials
It is used to hold power transmission parts in position
Bearings
They are used to prevent oil or any fluid from leaking through
bearing parts
Oil seals
- Used to transmit power from the driver shaft to the driven shaft
Pulley and belt
Part of the machine that transmits power at higher torque but at
lower speed from the driver to the driven shaft.
Sprocket and chain
They are used in transmitting power when the machines are
compact and shafts are placed close together.
Gears
- They are a direct-drive transmission system used to transmit power to a misaligned shaft.
- Commonly used in driving attached implement like rotary tiller, post-hole digger, and fertilizer applicator to the power take-off shaft of a tractor
Universal joints and flexible shafts
- is a device that produces intermittent motion or a specific motion to a member called follower
- It is a disc with a lobe on one side and, when rotated, produces intermittent motion
Cam
They are used to hold machine parts together
Bolts and nuts
They are externally threaded fasteners capable of being inserted into holes in assembled parts of mating with a preformed internal thread or forming its own thread.
Screws
They are low-cost permanent fasteners well suited to automatic assembly operation.
Rivets
- They are used on the end either beneath the head of the bolt or
beneath the nut. - They are used primarily as a seat to distribute load in a fastener
system.
Washers
They are inexpensive and effective fastener and are used when loading in shear. They are commonly used to fasten shaft in some control linkages
Pins
They are used to provide a removable shoulder to accurately locate, retain, or lock components on shaft or in bores and
housing
Retaining rings
