Texas MMET 201 Final Assessment with
Complete Solutions
Cutting - ANS-single - point or mulipoint cutting tools and processes, such as:
turning, boring, drilling, tapping, milling, sawing, and broaching
Material Removal Processes - ANS--cutting
-abrasive processes
-advanced machining processes
Advantages of Machining Processes - ANS--close dimensional accuracy
-may have features that can't be produced by other manufacturing processes
- more economical
Limitations of Machining Processes - ANS-1. They waste material, require more
energy and labor
2. takes more time than other processes
3. It can have adverse effects on the surface integrity of the product, including
fatigue life
Shear angle - ANS-influences force and power requirements, chip thickness, and
temperature
Continuous chips - ANS-formed at high cutting speeds and/or high rake angle
Serrated chips - ANS-called segmented or non homogeneous chips.
- Metals with low thermal conductivity and strength that decrease sharply with
temperature
- such as titanium
Discontinuous chips - ANS-forms when:
1. the workpiece material is brittle & contains hard inclusions and impurities
2. when cutting speed is very high or low
3. machine has low stiffness and poor damping
4. depth is large or rake angle is low
5. there is a lack of an effective cutting fluid
Thermosetting Plastics and Ceramics - ANS-tend to produce discontinuous chips
because they are brittle materials
thrust force is important because... - ANS-the tool holder, the workholding devices,
and the machine tool must be sufficiently stiff to support this force with minimal
deflections
Negative thrust force - ANS-friction at tool chip interface is low
, positive thrust force - ANS-when the rake angle is high
Specific cutting force - ANS-ratio of the cutting force to the cross sectional area
being cut (i.e., the product of width of cut and depth of cut)
Press working or Press forming - ANS-used commonly in industry to describe
general sheet - forming operations
Punching - ANS-the sheared slug is scrap, or may be used for some other purpose
Blanking - ANS-the slug is the part to be used and the rest is scrap
Die cutting - ANS-1. Perforating: punching a number of holes in a sheet.
2. Parting: shearing the sheet into two or more pieces
3. Notching: removing pieces (or various shapes) from the edges.
4. Lancing: leaving a tab without removing any material
Minimum bend radius - ANS-the radius at which a crack first appears at the outer
fibers of a sheet being bent
bending - ANS-As R/T decreases (the ratio of the bend radius to the thickness
becomes smaller), the material eventually develops cracks
Bendability - ANS-increased by increasing the temperature and pressure
Spring back - ANS-plastic deformation is followed by some elastic recovery when
the load is removed
Spring back increases with - ANS-- Increasing the ratio R/T and the yield stress of
the material
-decreasing the elastic modulus
Overbending - ANS-it can be achieved by rotary bending technique
.Coining - ANS-it is called bottoming
compensation for springback - ANS-1.Overbending
2.Coining: it is called bottoming
3.Stretch bending
4.Bending at elevated temperatures
forging - ANS-have good strength and toughness, and are very reliable for highly
stressed and critical applications
Open Die Forging Advantages - ANS--Simple
-inexpensive dies
-wide range of sizes available
-good strength characteristics
Complete Solutions
Cutting - ANS-single - point or mulipoint cutting tools and processes, such as:
turning, boring, drilling, tapping, milling, sawing, and broaching
Material Removal Processes - ANS--cutting
-abrasive processes
-advanced machining processes
Advantages of Machining Processes - ANS--close dimensional accuracy
-may have features that can't be produced by other manufacturing processes
- more economical
Limitations of Machining Processes - ANS-1. They waste material, require more
energy and labor
2. takes more time than other processes
3. It can have adverse effects on the surface integrity of the product, including
fatigue life
Shear angle - ANS-influences force and power requirements, chip thickness, and
temperature
Continuous chips - ANS-formed at high cutting speeds and/or high rake angle
Serrated chips - ANS-called segmented or non homogeneous chips.
- Metals with low thermal conductivity and strength that decrease sharply with
temperature
- such as titanium
Discontinuous chips - ANS-forms when:
1. the workpiece material is brittle & contains hard inclusions and impurities
2. when cutting speed is very high or low
3. machine has low stiffness and poor damping
4. depth is large or rake angle is low
5. there is a lack of an effective cutting fluid
Thermosetting Plastics and Ceramics - ANS-tend to produce discontinuous chips
because they are brittle materials
thrust force is important because... - ANS-the tool holder, the workholding devices,
and the machine tool must be sufficiently stiff to support this force with minimal
deflections
Negative thrust force - ANS-friction at tool chip interface is low
, positive thrust force - ANS-when the rake angle is high
Specific cutting force - ANS-ratio of the cutting force to the cross sectional area
being cut (i.e., the product of width of cut and depth of cut)
Press working or Press forming - ANS-used commonly in industry to describe
general sheet - forming operations
Punching - ANS-the sheared slug is scrap, or may be used for some other purpose
Blanking - ANS-the slug is the part to be used and the rest is scrap
Die cutting - ANS-1. Perforating: punching a number of holes in a sheet.
2. Parting: shearing the sheet into two or more pieces
3. Notching: removing pieces (or various shapes) from the edges.
4. Lancing: leaving a tab without removing any material
Minimum bend radius - ANS-the radius at which a crack first appears at the outer
fibers of a sheet being bent
bending - ANS-As R/T decreases (the ratio of the bend radius to the thickness
becomes smaller), the material eventually develops cracks
Bendability - ANS-increased by increasing the temperature and pressure
Spring back - ANS-plastic deformation is followed by some elastic recovery when
the load is removed
Spring back increases with - ANS-- Increasing the ratio R/T and the yield stress of
the material
-decreasing the elastic modulus
Overbending - ANS-it can be achieved by rotary bending technique
.Coining - ANS-it is called bottoming
compensation for springback - ANS-1.Overbending
2.Coining: it is called bottoming
3.Stretch bending
4.Bending at elevated temperatures
forging - ANS-have good strength and toughness, and are very reliable for highly
stressed and critical applications
Open Die Forging Advantages - ANS--Simple
-inexpensive dies
-wide range of sizes available
-good strength characteristics
