Machining Flashcards
Machining starts with a __________ of material and __________ material __________ to achieve a desired shape or finish
solid block, removes, gradually
Machining is Used extensively to:
1. Create parts from __________
2. Perform _________ operations on parts shaped by another principle
3. Make _______ or _______ to be used in other operations
4. Deliver a desired _________
Stock material, secondary, molds, dies, surface finish
Machining allows virtually unlimited _______________ with a very ___________ range of
production volumes
form freedom, large
What are the three machining methods we learned about?
Drilling, Turning, Milling
In many mechanical machining methods, the ___________of tool moves with _______________ through a solid slab of material at a _______ depth
Leading edge, constant speed, fixed
In machining, the tool is ______ shaped with an internal “____________” and Its position relative to material is defined by the _______ angle and the _______ angle
wedge, contour angle, relief, rake
____________+_________________+_________________= 90 deg
Relief angle, Contour Angle, Rake Angle
Machining is process of __________ deformation that is localized in a “shear zone” just ahead of cutting tool. The material is quickly sheared away by the tool while __________ heats the material rapidly
Plastic, friction
For isotropic materials, shear yield stress is about _________of tensile yield stress
50-60%
o
o The ________ angle prevents ________________in the
region behind the part
two directions
tangential force
vertical force
climbing
higher
elastically
springs back
relief excessive friction
What two directions does the tool apply force in?
Tangential & Vertical
In machining, a ______________ (Fh) allows the tool to cut in the horizontal
direction
Tangential Force
In Machining, a ______________(Fv) helps keep the tool from “______________” out of the material. Under this force, the material deforms __________ and _________ behind the tool while the ________ angle prevents ________________in the region behind the part
vertical, climbing, elastically, springs back, relief, friction
The ________ the rake angle, the higher the required Fv.
higher
For typical rake angles, Fh ≈ 1.5kt, where k is the ____________ and t is _______________
shear yield stress, cutting depth
What are the typical relief angles for:
Steel _____
Aluminum _________
Plastics _________
4, 6, 10
Machining generates heat from the _________________ and the ________ between the cutting tool and the part
Plastic deformation and friction
o About ______ of heat from machining ends up in chip
80%
__________ is often used in machining to remove heat, ________ chips and__________ the tool and machining surfaces but can be hazardous in work environments and pose environmental issues associated with disposal
Cooling fluid, wash away, lubricate,
Special alloys are sometimes used to __________ machining
Speed up
In materials with added alloys, certain elements such as ________ or _________
promote the formation of _____________ which are somewhat detrimental to material properties but promote weakness in the _________ resulting in a reduction in required _________
lead, sulfur, inclusions, shear zone, cutting forces
To produce ________________, try to avoid applying forces in ________ or __________
which produce much larger ___________ than forces in ___________ or __________ and consideration should be given to the clamping system used to
hold the part during machining
tighter tolerances, bending, torsion, deformation, compression, tension
Deformation considerations may dictate the ________ in which
machining tasks are completed
order
One way to reduce tool deformation is to __________ the required cutting force by making __________ cuts and reducing __________
reduce, shallower, tool size
When reduced tools and cut depth are used, In order to maintain ____________ , the tool speed must be __________ which is known as ________________. This Increases friction, so __________ tools are often used and ___________ becomes a problem when operating at high speeds, especially with thin parts
Productivity, increased, high speed machining, ceramic, vibration
When machining, __________ and __________ of cuts are __________ compared
to overall part, so cutting must be done in passes. Ideally, there would be no overlap between __________ , but inevitably there is which creates repeating surface pattern roughness
depth, width, small, passes
__________ are created when the tool “runs out” across edge of material
Burrs
__________ are created when the tool creates repetitive impressions on the part
Lay patterns
__________ is ideal for parts that have rotational symmetry
Turning
The __________ is the most common turning machine where the material is usually __________ on one side with a chuck and then fixed on the other with a __________
Lathe, clamped, center pin
Typical lathes turn in a range between __________ rpm
1000-5000
What type of Drilling is described here?
o Drilling a hole to act as a guide for drilling the final hole
Spot Drilling
What type of Drilling is described here?
o A stepped hole in which a larger diameter follows a smaller diameter partially into the hole
Counterboring
What type of Drilling is described here?
o Similar to counterboring, but the hole is cone-shaped
Countersinking
What type of Drilling is described here?
o Precisely enlarges an existing hole
Boring
What machining method is described here?
o In milling, material is moved below a spinning tool
o Material moves in multiple axis (at least two , but often
three)
What variety of Mill is Described Below?
o Long narrow cylinder for making slots and fine details
End Mill
What variety of Mill is Described Below?
o Short squat cylinder for removing a lot of material fast
Slab Mill
What variety of Mill is Described Below?
o Has spherical head and can create double curved shapes
