Sheet Metal Processes Flashcards
Sheet metal has a ___ surface area and a ___ thickness.
large; small
Effects of residual stresses
Non-uniform deformation
Stress remains in material after force is removed
Cracking can occur
Springback
When metal pops back after bending
Shearing
Think scissors, metal is broken in two using a punch and a die
Die cutting
Like a cookie cutter
Minimum bend radius
The radius when cracks first start to appear while bending
Ways to compensate for springback
Overbending (just bend it further than you need to)
Coining (compressive stresses localized)
Stretch bending (stretch, hold tension, and bend)
Elevated temperature (decreases yield stress)
Hemming
Hides sharp edges by folding them over
Beading
Sheet edge bent into die cavity
Flanging
Edge is bent 90 degrees to improve stiffness
Dimpling
Punched hole expanded until it becomes a flange
Air bending
Sheet bent into open space, no downward movement constraints
Stretch forming
Sheet is stretched over protruding die
Deep drawing
Sheet is pushed into convex die
Bulging
Hollow part is expanded using a rubber plug in a split die
