Sand casting , what is sand casting???

                         SAND CASTING

Casting =

Pattern making + Mold making + Pouring

Molten Metal + Cooling + Removal +

Inspection

Types of Casting :

Expendable Mold, Multiple Use Mold

Sand Casting :

Expendable Mold casting process uses sand

as molding material.

Pattern Making

What is pattern?   

Approximate duplicate of product

Pattern material: Wood, Metals, Urethanes

etc.

Types of Patterns:

One Piece or solid pattern, Split Pattern,

Match-plate pattern, Drag & Cope Pattern

Allowances:

Shrinkage, Machining, Draft, Distortion 

Mold Making

 Consists : Sand Preparation and Mold Making

 Sand Properties :

Refractoriness, Cohesiveness, Permeability,

Collapsibility

 Mold Making Methods:

Hand Ramming, Sand Slinger, Jolting,

Squeezing, Combination 

Removal of Casting:

Shake out-vibrating machine

Shot blasting-Removal of internal surface sand

Trimming:

Excess material-manual cutting, sawing         ￾Trimming Press

Inspection:

Nobody is perfect…Sand Casting too…Defects…

Different Sand Casting Processes:

Green Sand Casting:

88% silica sand, 9% clay,3% water

CO2 Molding:

Sodium Silicate(3-6%)-CO2 flow- Strength Gain

Shell Molding:

Silica Sand + Thermo setting phenolic resin+ heat sensitive liquid

catalyst-shot on preheated metal pattern-shell formation