Please enable JavaScript.
Coggle requires JavaScript to display documents.
Mechanical Practice 1 (Sat 08/01/2022_Week 01) - Coggle Diagram
Mechanical Practice 1 (Sat 08/01/2022_Week 01)
Introduction
The change of the metal workpiece shape is plastic deformation
We use a die to take the desired metal shape
Metal forming includes a large group of manufacturing processes
Metal forming
Sheet metal working
Shearing
Drawing
Bending
Bulk deformation
Forging
Extrusion
Rolling
Drawing
Plastic region
strain "∈"
strength coefficient "K" (MPa) ⇊ high temperature
stress "σ"
strain hardening exponent "n" ⇊ high temperature
σ = K.∈^n
ductility (plastic deformation of work metal) ⇈ high temperature
cold, warm & hot
d = t(i) - t(f) = r.t(i)
thickness "t" (mm = in)
reductio "r"
draft "d" (mm = in)
t(i).w(i).L(i) = t(f).w(f).L(f)
t(i).w(i).v(i) = t(f).w(f).v(f)
work length "L" (mm = in)
work velocity "v" (m/s = fl/sec)
work width "w" (mm = in)
s = [v(f)-v(t)] / v(r)
work velocity "v" (m/s = fl/sec)
roll speed "v(r)" (m/s = fl/sec)
forward slip "s"
Each roll
average flow stress "Y"
torque "τ" (J = in - lb)
P = 2π.N.F.L
power "P" (J/s = W = in - lb/min)
τ = F.L/2
rotational speed "N" (1/s = rev/min)
L^2 = R.[ t(i) - t(f) ]
rolling force "F" (N = lb)
F = Y.w.L
contact length "L" (m = in)
Y = K.∈^n / (1 + n) with ∈ = ln[ t(i) / t(f) ]
dmax = μ^2.R
μ(cold) = 0.1
μ(warm) = 0.2
roll radius "R" (mm = in)
coefficient of friction "μ"
μ(hot) = 0.4