The micro forming or laser micro deep drawing is defined as the production of sheet metal with range in sub- millimeter at least two- dimensional part to be make in this process. A micro- part concerned with small sub- millimeters until few millimeters with in typical part- dimension. It process achieved such a manner miniaturization of sheet metal components is numerous and varied from the conventional metal of formed technique like as stamping and cold forming.
The micro deep drawing technique such as
- Superplastic forming
- Micro (or) Nano- imprinting
- Deep drawing
Micro deep drawing Process:
It is a laser forming process used and differ thermal mechanism caused by a bending the sheet metal. When the non- thermal mechanism used to provide a micro deep drawing. which is used to optical low- threshold surface breakdown, to make a shock wave. The shock wave means of the responsible energy to provide in surface of forming of forming process. The velocity of forming process is driven through the shock wave velocity. The forming process can be compare to high speed forming like as explosive forming or electromagnetic forming.
- The test layout for a deep drawing work is similar to the process of laser stretch forming
- The laser is induced the shock wave for the sheet metal as long as in microscopic range to make a part.
- The sheet metal is placed on the drawing die and cut with circular shape by using a laser. The drawing die is having diameter of 5 mm.
- Then the blank holder is placed on the blank with a blank holder force. But below the clamping force.
- One or more short laser pulse hit with specimen to focus blank surface.
- Q-switch ND: YAG type of laser used in this process with maximum power density of 1.7 GW/ cm2. The process consider for thermal damage and mechanical deform.
- The high energy of density in the laser radiation initiate ionization of close by atmosphere and plasma forming process take place.
- When the plasma caused by a shock wave. If the laser pulse density exceeds a certain threshold. Which shock wave disintegrates the components from specimen.
- The laser draw cup is released from the die
- The process is long than laser pulse time duration of 20- 80 ns. Since shock wave propagation, plasma formation and forming process occurred.
Aluminium sheet metal of 50 um thickness which is laser stretch- forming to a hemispherical done with the diameter of 1 and 12 mm. co2 laser induced 40 time high wave length more suitable for this deep forming process than excimer laser. That not caused by a ablation on the surface of metal, but just make a shock waves Nd: glass laser wavelength is about 5 time more than excimer laser.
Advantage of micro deep drawing process:
- The production rate is high
- Material loss is minimum (or) zero
- The final product having excellent mechanical properties
- Close tolerance
- Mass production
Application of micro deep drawing:
That process to make a micro product and micro metal components has strongly increased in industry clusters such as automotive, telecommunication, health care and military. The application as follow