Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

EN1211 - Materials + Manufacturing > Manufacturing > Flashcards

Manufacturing Flashcards

1
Q

what is machining? advantages + disadvantages?

A

Material removed to create final component–subtractive process

  • Advantages:
  • High precision
  • Good surface finish achievable
  • Disadvantages
  • Slow process, therefore can be expensive
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Turning

A
  • Removes material from outer diameter of workpiece
  • Allows specified diameter to be created
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Facing

A
  • Removes metal from end of workpiece
  • Creates flat end surface
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Parting off

A
  • Cuts workpiece to specified length
  • Parting tool driven transversely into workpiece
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Thread
Cutting

A
  • Creates threads by cutting a helical ridge on workpiece
  • Cutter driven at specific speed (by leadscrew or CNC
    motor)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Boring

A
  • Removes internal material from a workpiece
  • Straight and tapered holes can be created
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Knurling

A
  • Creates a textured surface by pressure or by cutting
    material
  • Specialist tool imparts pattern
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

3 jaw “self centring”
chuck

A
  • All jaws move at same time
  • Component automatically gripped in centre
  • Low accuracy (±0.25mm)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

4 jaw “independent”
chuck

A
  • All jaws move independently
  • Allows workpiece to be manually aligned
    accurately
  • Can accommodate more complex shapes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Collet chuck

A
  • Precision made, high accuracy (±0.025 mm)
  • Only accommodates specified size workpiece
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Turning between centres

A
  • Mounts component centrally on its axis
  • Allows accurate transfer between processes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

CNC lathe

A
  • Fully automatic
  • Computer Numerically Controlled
  • Follows programmed operation sequence
  • Motors drive movement
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Milling

A

used for:
- Surface cutting (plane or curved)
- Form milling (e.g. key slot, T-slot)
- Gear cutting
- profile duplication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Vertical milling machine

A
  • Vertical spindle
  • Tool gripped at one end
  • 3 or 5 axis variations
  • Cavities and pockets can be created
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Horizontal milling machine

A
  • Horizontal spindle
  • Tools supported at both ends
  • Large cuts possible
  • Less flexible than vertical milling
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Up-cutting
(conventional)

A

Tool sharpness important due to forces
involved

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Down-cutting (climbmilling)

A

Good surface finish achieved
* Less power consumed
* Backlash a major problem
* High machine rigidity required

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Backlash

A
  • Clearances can cause free “play” – known as
    “backlash”
  • Unwanted / uncontrolled movement in
    system
  • Wear increases backlash
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Straddle Milling

A
  • Multiple cutters spaced to cut both sides of
    workpiece at once
  • Precise setup required
  • Improved processing speed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Gang Milling

A
  • Multiple cutters grouped to form surface
  • Expensive setup and maintenance costs
  • Improved processing times and alignment
  • Setup can be maintained for batch production
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Gear Cutting

A
  • Uses a “dividing head”
  • Allows workpiece to be divided into set angles
  • Gear cutter forms shape of teeth
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Duplex Milling

A
  • Allows simultaneous working of both sides of
    workpiece
  • Motion replicated on both sides
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Copy / Profile
Milling

A
  • Machine follows original part to generate copied
    profile
  • Bullnose or “copy cutter” used
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Plano Mill

A

Allows multiple independent actions to be carried
out at once
* Can by automated using CNC control

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Drilling

A
  • Low Cost
  • Efficient
  • Poor heat removal
  • Poor accuracy/finish
  • Swarf removal difficult on deep holes
  • Depth > 5x diameter
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Broaching

A

Produces special shaped holes, slots and
external surfaces
* Fast, low cost operation
* Successive teeth remove material
* Machining completed in one pass
8
* Pull and push variants available
* Very high tool cost
* Excellent repeatability

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Thread cutting – tap and die

A
  • Operation: Manual, lathe, drill press/tapping head
  • External threads cut using:
  • Circular split dies, solid nut dies
  • Coventry die head for capstan use
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Casting
advantages+disadvantages?

A

Advantages:
* Final shape produced in a single step
* Complex shapes possible
* Low component cost
Disadvantages:
* Poor surface finish
* Poor dimensional accuracy
* Low component strength
* High setup and energy cost

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Casting: Pattern, Material and Shrinkage

A

Pattern required:
* Duplicate shape of part
* Can be made from:
- Wood: low quality
- Plastic: e.g. produced by 3D printing
- Metal: expensive, robust
* Draft required to allow removal from mould
Must consider shrinkage, finishing operations and distortion
* Typical shrinkage:
- Cast iron: 1%
- Steel: 2-2.5%
- Al, Mg: 1-1.3%
- Brass: 1.5%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Components of a casting mould

A

Cope and Drag: Top and bottom halves of mould
Riser: Liquid metal reservoir
Cores: For hollow sections
Core print: Supports core

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Sand Casting

A

Traditional casting process
* Numerous materials, design flexibility, low cost
process, low volume production possible
* Poor finish, accuracy, component strength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Shell moulding

A
  • Hot metal pattern dipped into fine sand mixed
    with resin to form thin shell
  • Mould split and baked, placed in pouring jacket
  • Good tolerance, surface finish and productivity
  • High labour / process cost
30
Q

Vacuum moulding:
V-Process

A
  • Vacuum used to maintain the mould shape
    during casting – no binder required in sand
  • Sand immediately reusable after demoulding,
    little / no fumes
  • Slow process – normally used in prototypes
31
Q

Freeze moulding:
“Eff-Set” process

A
  • Moulds made from sand, clay and water using
    permanent patterns - water frozen for rigidity
  • Castings have good finish
  • Sand immediately reusable
  • Not commercially available
32
Q

Full Moulding

A

AKA: Evaporative Casting, Lost Foam, Expanded
polystyrene
* Polystyrene foam pattern, ceramic coated and
loose sand packed - pattern decomposes
during pouring
* No parting line, one-offs possible, poor surface
finish

33
Q

Investment Casting

A
  • Similar to shell moulding but with a “rubbery”
    mould
  • Greater variety of shapes possible – flexible
    mould allows slight undercuts
  • Expensive, possible parting line
34
Q

Rubber mould
casting

A
  • Reusable rubber mould
  • Only suitable for casting low melting point
    materials, e.g. wax, plastic, “Wood’s metal”
35
Q

Gravity Die
Casting

A

Uses metallic die (mould) - preheated
* Reusable mould
* Good finish, tolerance, High productivity,
Controlled cooling
* Limited mould life, high tooling costs

36
Q

Die Casting
(Pressure Die
Casting)

A

Hardened tool steel dies, metal cores
* High pressure applied during solidification
* High process speed, high complexity and detail
possible, low porosity
* Very high tooling and equipment costs

37
Q

Slush Casting

A
  • Pour molten metal in the mould, “slosh about”,
    cooling the outside shell - pour out when thin
    shell is formed
  • Poor quality – limited to “decorative” items
38
Q

Centrifugal
Casting

A

Use centrifugal force for casting hollow parts
* Consistent wall thickness, dense, high quality
structure
* Limited to cylindrical geometries

39
Q

Centrifuge Casting

A
  • Use centrifugal force to apply pressure
  • Produces dense/homogeneous castings
  • Used for small, high quality parts (e.g. jewellery,
    dental implants)
40
Q

Squeeze Casting

A

Partially solid metal is squeezed in a die
* Pressure maintained until full solidification
* Homogeneous components, similar properties to
forging
* Little commercial use

41
Q

Continuous
Casting (con-cast)

A
  • Used in heavy industry (e.g. steel works)
  • Surface solidifies in mould, bulk solidifies as
    material passes along rollers
  • Impurities remain in “Tundish”
42
Q

Finishing Operations & Design Considerations

A

Finishing:
* Cleaning
* Machining
* Defect repair
* Heat treatment
* Inspection
Design Considerations:
* Parting line location
* Avoid sharp corners or edges
* Uniform thickness / gradual thickness
change

43
Q

Joining

A
  • Engineering systems are complex
  • Individual parts are easier to manufacture
  • Products can be disassembled for maintenance
  • Allows use of different materials
  • Promotes mass production and reduces cost
44
Q

Mechanical
Joining

A

Can be temporary (e.g. nut and bolt) or permanent
(e.g. rivets, crimps)

45
Q

Forge Welding

A

Deformation in hot working condition
* Oxide and contaminants are squeezed out
* Develop inter-atomic bonding

46
Q

Cold welding:
“Coalescence”

A
  • Localized pressure, large amount of cold work
  • Vacuum required
  • Used for small parts
47
Q

Friction Welding

A
  • Rotational friction and pressure
  • Welded throughout joint - strength almost the
    same as the base material
  • Typically used for drive shafts
48
Q

Ultrasonic Welding

A
  • Ultrasonic vibration and pressure applied
  • Restricted to thin, small, parts, e.g. electronic
    components, plastic components
49
Q

Diffusion Welding

A
  • Flat and highly polished surfaces held together
    under pressure and heated in inert
    atmosphere
  • Limited deformation, high bond strength
  • Slow process - 15 minutes to several days
  • Good for welding Ti-based super-alloys (e.g.
    aircraft components)
50
Q

High frequency
welding

A
  • Induction coil used to induce eddy currents
  • Creates localized heat at joint faces – small
    HAZ
  • Pressure applied to forge the joint
  • Highly conductive material can be easily joined
51
Q

Explosive welding

A
  • Temperature and pressure produced by
    explosion
  • Produces bond not easily achieved by other
    means - large areas bonded very quickly
  • Can weld metals with different melting points
  • A way of cladding materials to increase
    corrosion resistance
52
Q

Oxy-fuel Gas
welding

A
  • Heat from burning Acetylene (C2H2) and Oxygen
  • Usually uses filler
  • Oxide contamination leads to poor weld quality
  • Heat is not concentrated, slow, large HAZ
53
Q

Arc Welding

A
  • Electric arc provides heat, gas required (from
    flux) to stabilise arc and protect weld
  • Shielded metal arc welding – “MMA”: coating
    creates gas shield, alloying elements (slag must
    be removed)
  • Electrode is consumed
54
Q

Flux cored
welding

A
  • Flux inside electrode:
  • Good control of welding parameters
  • Thinner electrode size needed
55
Q

Submerged arc
welding

A

Granular flux gives excellent shielding: high
quality weld
* Filler wire fed from reel
* High speed and deep weld penetration

56
Q

Gas metal arc
welding

A
  • MIG (Metal Inert Gas) or MAG (Metal Active Gas)
  • Uses Argon, Helium, CO2, or mixture of shielding
    gases, fed through nozzle
  • Consumable wire reel electrode: easy to automat
  • No/very little slag to remove
57
Q

Gas tungsten arc
(TIG)

A
  • Non consumable electrode, constant arc
  • Separate filler rod used, inert gas supplied as
    shield
  • High quality weld, deep penetration
  • Skilled manual operation: slow speed, high cost
58
Q

Plasma arc
welding /
cutting

A
  • High gas temperature due to ionization by arc:
    temperature up to 20,000°C
  • High energy concentration: localized heating
  • Fast, deep penetration, narrow HAZ
  • Temperature can be controlled through gas
    selected
59
Q

Resistance
Welding

A

Weld formed through heat from electrical
resistance and pressure – no filler used
* High reliability, small HAZ, low distortion, simple
automation, can weld plated metals
* Discontinuous weld, limited to lap joints

60
Q

Projection
welding

A
  • Projections pre-pressed into components -
    multiple simultaneous welds possible, precise
    weld location
  • Lower contact resistance for same force
  • Less wear on electrodes than resistance welding
61
Q

Exothermic
“Thermit”
welding

A

Heat produced by exothermic reaction, e.g.
“burning” aluminium and iron oxide:
8Al + 3Fe3O4 → 9Fe + 4Al2O3
* Typical uses: rails/large castings, cutting scrap
metal

62
Q

Electroslag
welding

A

Joins thick plates in single pass - whole face
welded
* Consumable electrodes act as filler - vertical feed
* Used for large bridge sections, boiler shells, etc.

63
Q

Electron beam /
Laser beam
welding

A
  • Single pass welding of thick material, precise
    welding of small components - high precision,
    low heat input
  • Very high equipment costs
  • Cutting holes with length/diameter ratios up to
    25:1
64
Q

Hot Air Welding

A
  • Fusing/repairing plastics - filler rod often used
  • Reflowing solder during circuit board fabrication
65
Q

Joining methods – welding problems

A

Distortion in joints:
* Care needed to minimise deformation in joint design
Challenges in liquid state welding:
* Material composition changes
* Cavities, contamination
* Residual stresses
* Most failures start at the HAZ
* Must consider cost of multi-run welds and joint preparation

66
Q

Forming? advantages + disadvantages

A

Forming involves plastic flow in the solid state.

Advantages:
* Fast production
* Efficient material usage
* High strength components, due to Work hardening, grain refinement and defect closure
* Better surface finish and tolerance than casting
Disadvantages:
* High force requirements - specialist equipment
* Tooling can be expensive
* Inferior surface finish and tolerance to machining
* Friction consumes ~50% energy input and causes die wear
* Anisotropy can be a problem

67
Q

Open Die Forging
“Smith” Forging

A
  • Involves hammering at high temperature
  • Oldest method
  • Low quantity production
68
Q

Closed Die
Forging

A
  • Heated metal formed to shape between two
    shaped dies – hammering used in drop forging
  • Excess metal used: flashing
  • Machining allowance needed for finishing
69
Q

Press Forging

A
  • Slow, uniform deformation
  • Improved dimensional accuracy and fewer
    intermediate steps (than drop forging)
  • Cooling dies often required due to longer contact
70
Q

Upset forging

A
  • Material gripped so that requisite length projects,
    upset area is heated
  • Forging performed by moving die/punch
  • Typical use – bolts, headed components
71
Q

Hot Rolling

A
  • Used for long lengths of uniform cross section
  • Friction drives the material between rollers
  • Typically used for flat rolling, shape rolling, roll
    forming of pipes (e.g. seamless pipes on
    Mannesmann mill)
72
Q

Thread Rolling

A
  • Threads can be hot or cold rolled
  • Material grain structure follows thread
73
Q

Cold Rolling

A
  • Usually follows a hot rolling operation
  • Pickling used to remove scale
  • Good surface finish, thickness control and workhardening (often desirable)
74
Q

Extrusion

A
  • Material pushed through shaped die (hot or cold)
  • Can produce complex geometries with constant
    cross section
  • Normally used with non-ferrous alloys
75
Q

Rod, Tube & Wire
Drawing

A

Material pulled through shaped die
* Good surface finish and accuracy, work
hardening often desirable, lubrication is crucial
* Typical max. reduction in area is about 20% per
pass

76
Q

forming methods - sheet metal working

A

EN1211 - Materials + Manufacturing (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions