Investment Casting (Lost Wax Process)

Investment casting is expandable mold metal casting process which is also known as lost wax process because the pattern is made up of wax and is melted away when it is heated. Wax is recovered and can be used again and again that’s why this process is called investment casting process.

Steps involve in investment casting

Step 1 

First and most unique step is the making of the patter which is of wax. A few number of pattern are attached to the wax sprue

Step 2

Pattern attached to wax sprue is then fully dipped in the refractory material tank so that it is fully covered by the refractory material. It is them drayed to make it rigid

Step 3 

Pattern is now inverted and heated to remove the wax from it. After the removal of the wax patter is now hollow from inside and metal can be poured in it

Step 4

To remove all the contaminants from the mold it is heated at very high temperature and them hot molten metal is poured into it and then kept for a long time for cooling

Step 5

After the metal is cooled refractory material is removed and pattern is removed from the metal sprue

Advantages of investment casting

• Complex parts can be manufactured
• High dimensional control
• Good surface finish
• Wax is recovered
• No machining is required
• Net shape process

Disadvantages of investment casting

• Take more time than other processes
• Expansive than other processes