Introduction

Lost Wax Casting/ Investment Casting:
Investment casting is a process where a wax pattern is used to form a ceramic shell in which molten metal is poured to cast the desired parts. This process is also known as “Lost-wax Casting” or “Precision Casting”. In this casting process, “Investment” of the refractory coating material is done on surface of the wax pattern.
A replica of the part to be casted, is created using wax which is called as wax pattern. Later, all patterns will be assembled on a runner to form a wax tree assembly. Multiple coats of refractory ceramic material are applied on a wax tree assembly. Upon drying of ceramic coating, wax is drained out of the coating by melting it and a ceramic shell is formed. Ceramic shell is heated upto certain temperature to achieve shell hardness and remove left-over wax.
Shell with the cavity in a shape of the part to be casted, is going to be used as an expendable investment mold. Molten metal is poured into this investment mold, where it will solidify and form a part. Later this mold is broken out to get the casted parts.
Capability to cast complex parts and excellent as-cast surface finish makes Investment casting a preferred casting method over other casting methods. Also, the parts casted with investment casting method requires less casting tolerance compared to other casting methods.

Experience and dedication ensure exceptional results in wax casting manufacturing industry.


Step.1 Tool & Die Making

The Die are develop as per the requirement of Customer . Dies can be develop in Steel, Aluminium or Soft Metal.The first step involves designing and building a 3D model and cavity in the solid block by various means of machining setup.


Step.2 Wax Injection

The die creates a wax replica of the desired part by injecting melted wax under high pressure into the cavity. The die can be made as a simple one cavity manual tool or a complex multi-cavity automatic tool depending on volume requirements.


Step.3 Wax Assembly

In this process the patterns are attached to a wax sprue to create a pattern cluster, or can be called tree. To attach patterns, a heating tool is used to slightly melt the desired wax surfaces, which are then pressed against each other and left to cool and harden.

Step.4 Coating

The ceramic known as the Investment is a repeating a series of steps coating, stuccoing and hardening until a desired thickness is achieved. Coating involves dipping a pattern cluster into slurry of fine refractory material and then draining to create a uniform surface coating and the deep in to stucco to built-up the thickness.

Step.5 De-Waxing

Once ceramic moulds have fully cured, they are turned upside-down and placed in a steam autoclave to melt out the wax.Any wax that runs out of the mould is usually recovered and reused.

Step.6 Melting

The investment mould is then placed open-side i.e cup side up into a sand bed and then the molten metal is poured in a hot shells which are pre heated in a shell baking furnace. After Pouring the metal shell are send to fettling section for finishing of the castings.


Step.7 Shell Removing

After casting, we need to remove the shell to obtain the castings. Factories usually use a vibratory process to remove the shell and blast to clear the refractory material adhering to the castings.


Step.8 Cut and Remove Casting Ingates & Risers

Once the casting cluster is cleaned up, we need to cut each casting off. The casting ingates and risers are ground off with the abrasive belt grinding machine to form the individual castings..


Step.9 Finished Parts for Inspection and packing

Once the casting cutting and grinding completed, The products are ready for inspection as per customer requirements and then packed and shipped to them.


PROCESS