Gravity die casting

1. {
Presentation on
Gravity Die Casting
Presentation By- Saliganti Shiva Kumar
M.Tech-1st Year
FFT (2018-20)
NIFFT Ranchi

2. INTRODUCTION:
Gravity die casting (or) Permanent mold
casting uses mold which is permanent .
Molten Metal is poured into mold under
gravity only, no other pressure is applied to
pour the molten metal . However liquid metal
solidifies under pressure of metal in the risers
.

3. Permanent molds:
 These are made of dense, fine grained, heat resistant cast iron,
steel, bronze, aluminium , graphite or other suitable
refractories.
 This is made into two halves in order to facilitate the removal
of casting from the mold .
 This is designed with horizontal or vertical parting line like as
in sand molds .
 Pouring cup , sprue, gates and riser are built in the mold halves
itself.
 The two mold halves are securely clamped together before
pouring.

4.  Cores for this type of casting used is metal
generally or dry sand.
 For facilitating the removal of metal cores ,
surfaces should have a draft of at least 3 to 5
degrees.
 Molds using dry sand cores or shell cores are
known as semi- permanent molds.
 Dry sand cores positioned and supported in
core prints.
Cores for permanent molds

5.  This coating is nothing but refractory coating.
 After the mold surfaces have been heated to the
required temperature , a refractory coating is
sprayed on the mold cavity .
Chills:
A chill is used to promote directional solidification.
These are mostly pieces of Cu , Brass or Aluminium and
are inserted into the mold’s inner surface .
Coatings:

6. Permanent mold casting
production:

7.  Carburetor bodies
 Hydraulic brake cylinders
 Refrigeration castings
 Oil pump bodies
 Aircraft and missile castings
Applications: