Manufacturing Processes 1 Final
Exam
Metal Forming - Answer-Slides 1
Bulk deformation - Answer-Thickness or cross-sections are reduced or shapes are changed significantly
Localized deformation - Answer-Thickness or surface area remains relatively constant
Sheet Forming Processes - Stamping - Answer-the process in which thin walled metal parts are shaped
by means of punches as dies driven by mechanical or hydraulic presses
Examples
razor blades
cans
door panels
door hinges
Sheet Forming Processes - Shearing - Answer-Mechanical cutting of materials without the formation of
chips or the use of burning or melting
- exceeding the shear strength of the material
- Holes, slots, grooves, etc. cut by excessive shear
,Clearance between die and punch is less than sheet thickness
What is the clearance between die and punch? - Answer-Less than the sheet thickness
Sheet Forming Processes - Non-shearing(forming, drawing, bending) - Answer--Exceeding the yield
strength of the material
Punch and die have rounded corners
Clearance between die and punch is MORE than sheet thickness
Shearing - Possible Features - Answer-Notch
Slits
Holes
Slots
Perforations
uses lancing
Shearing - Basic types - Answer-Blanking
Cutting up a large sheet of stock into smaller pieces suitable for the next operation in stamping, such as
drawing and forming
Shearing - Basic types - Answer-Piercing
Cutting features inside the workpiece
,What are the basic types of shearing used for? - Answer-Produce intermediate blanks
Produce features
Separate/remove part from strip of sheet metal
Trim a part for size control
Non-shearing: Bending - Answer-Bending - plastic deformation of material
The material is stressed beyond the yield strength but below the ultimate tensile strength (mild steel
tensile strength is 60000 psi)
Tooling
-Punch
-Die
Springback (elastic recovery) is an issue
When bending pressure is removed, elastic energy in bent part, causing it to partially recover toward its
original shape
Non-shearing: Drawing - Answer-Converts a thin, flat, circular blank into a recessed cup
Punch has rounded corners to prevent shearing
Non-shearing: Embossing - Answer-Drawing used to form shallow indentation such as lettering or other
designs
Depth limited to 1 TO 3 times the thickness of the metal
, Applications
-Market Branding
-Serial Number
-Instructions
Stretch Forming - Answer-Produces large sheet metal parts
Process:
-Two or more sets of jaws hold the workpiece in tension
-Force die into workpiece
---Move die
---Move workpiece
Stretch Forming 2 - Answer-Used in aerospace industry to produce parts with a large radius
Used in automotive industry to shape body panels
Spinning - Answer-A rotation disk of sheet metal progressively shaped over a male form or mandrel to
form symmetrical shapes
-Seamless, hollow rotationally symmetric shapes
-Cylinders
-Cones
-Hemispheres
Lathe Based
Exam
Metal Forming - Answer-Slides 1
Bulk deformation - Answer-Thickness or cross-sections are reduced or shapes are changed significantly
Localized deformation - Answer-Thickness or surface area remains relatively constant
Sheet Forming Processes - Stamping - Answer-the process in which thin walled metal parts are shaped
by means of punches as dies driven by mechanical or hydraulic presses
Examples
razor blades
cans
door panels
door hinges
Sheet Forming Processes - Shearing - Answer-Mechanical cutting of materials without the formation of
chips or the use of burning or melting
- exceeding the shear strength of the material
- Holes, slots, grooves, etc. cut by excessive shear
,Clearance between die and punch is less than sheet thickness
What is the clearance between die and punch? - Answer-Less than the sheet thickness
Sheet Forming Processes - Non-shearing(forming, drawing, bending) - Answer--Exceeding the yield
strength of the material
Punch and die have rounded corners
Clearance between die and punch is MORE than sheet thickness
Shearing - Possible Features - Answer-Notch
Slits
Holes
Slots
Perforations
uses lancing
Shearing - Basic types - Answer-Blanking
Cutting up a large sheet of stock into smaller pieces suitable for the next operation in stamping, such as
drawing and forming
Shearing - Basic types - Answer-Piercing
Cutting features inside the workpiece
,What are the basic types of shearing used for? - Answer-Produce intermediate blanks
Produce features
Separate/remove part from strip of sheet metal
Trim a part for size control
Non-shearing: Bending - Answer-Bending - plastic deformation of material
The material is stressed beyond the yield strength but below the ultimate tensile strength (mild steel
tensile strength is 60000 psi)
Tooling
-Punch
-Die
Springback (elastic recovery) is an issue
When bending pressure is removed, elastic energy in bent part, causing it to partially recover toward its
original shape
Non-shearing: Drawing - Answer-Converts a thin, flat, circular blank into a recessed cup
Punch has rounded corners to prevent shearing
Non-shearing: Embossing - Answer-Drawing used to form shallow indentation such as lettering or other
designs
Depth limited to 1 TO 3 times the thickness of the metal
, Applications
-Market Branding
-Serial Number
-Instructions
Stretch Forming - Answer-Produces large sheet metal parts
Process:
-Two or more sets of jaws hold the workpiece in tension
-Force die into workpiece
---Move die
---Move workpiece
Stretch Forming 2 - Answer-Used in aerospace industry to produce parts with a large radius
Used in automotive industry to shape body panels
Spinning - Answer-A rotation disk of sheet metal progressively shaped over a male form or mandrel to
form symmetrical shapes
-Seamless, hollow rotationally symmetric shapes
-Cylinders
-Cones
-Hemispheres
Lathe Based
