Lost wax casting is a precise way used to create complex metal casting parts with high-accuracy details like bucket teeth. The main process of lost wax casting, also known as investment casting, involves the following steps:
Pattern Creation:
A detailed and precise wax pattern of the bucket teeth is created as a mold and then by injecting molten wax into this wax mold.
Wax Model Assembling：
The wax patterns are attached to a central wax sprue, forming a wax mold tree. This tree can hold multiple wax patterns for efficiency.
Shell Coating :
The tree with wax patterns is coated with a ceramic slurry. This process involves dipping the tree into a fine ceramic material multiple times to build a strong ceramic shell outside the wax patterns. Each layer is dried before the next application to ensure an even and robust shell.
De-waxing:
The ceramic shell with the wax patterns inside is heated in an autoclave or furnace. The heat melts and removes the wax, leaving behind a cavity in the shape of the intended bucket teeth. This step is crucial for creating the mold for casting.
Shell Roasting:
The ceramic shell containing the cavity left by the wax pattern is subjected to high temperatures to remove all residual wax and moisture before the molten metal is poured in.
Compound analysis and Casting:
The metal alloy steel is analyzed to determine its chemical composition. This analysis ensures that the alloy steel meets the specified requirements of bucket teeth impact strength and durability.
The ceramic shell is preheated to a specific temperature to prepare it for receiving the molten metal. Molten metal is poured into the ceramic mold, filling the cavity left by the wax pattern.
Shell Removal and Sand Cleaning:
Once the metal has fully solidified, the ceramic shell is broken or removed. This can be done by mechanical means like vibration, or sandblasting. The bucket teeth is revealed, usually with a rough surface due to the shell removal. The parts also need to be cut off from the trees and then make a shot blasting to refine the surface finish
Heat Treatment:
The parts must undergo heat treatment processes such as quenching, and tempering to help improve the mechanical properties of the casting bucket teeth, such as hardness, strength, toughness, and ductility.
Painting and packing:
After Heat Treatment the bucket teeth need to go through shot blasting again and inspection to make sure all the fitment is correct. After that, the bucket teeth will be painted and packed into the warehouse.
