Weight: 5g – 50kg
Capability: 150 ton per month
Machining tolerance: +-0.01-0.03mm
Surface Roughness: 6.4 Ra um/ 254 Ra uinches
Tight tolerance: CT4-6
1)Less than 100g: 1000 pcs
2)100g-200g : 500 pcs
3)More than 200g 200 pcs
Table of Contents
What is Investment Casting?
Investment casting can also refer to lost-wax casting. Investment casting has more than 5,000 years in numerous forms. There are two main investment casting methods, silica sol investment, and water glass investment. In addition, The silica sol investment casting costs more but has a better surface than the water glass method.
The investment castings involve creating an original wax pattern, coating layers of plaster, and building successive layers until a strong shell envelopes the model. Then, melted material is poured into the mold, creating an exact duplicate of the desired part.
Applications of Investment Castings
The investment castings parts could be applied to medical equipment, food service, beverage industry, power generation, automotive, aerospace, gas, and oil and energy industries applying other precision parts.
For example, the gas and oil industry turns to cast parts for impellers, valves, and fittings. Investment castings are even used by truck spare parts in the transportation industry.
Advantages of Investment Casting
- high dimensional accuracy and surface finish, so it can reduce the machining work, leave a little machining allowance in the parts with higher requirements, or even some castings only leave polishing and polishing allowance, and can be used without mechanical processing. It can be seen that the investment casting method can save a lot of machine tools and processing time, and greatly save metal raw materials.
- cast a variety of complex shapes, high precision alloy casting, especially high-temperature alloy casting. For example, the blades of a jet engine, with their streamlined shape and cooling chamber, are difficult to form by machining. It can realize mass production and ensure the consistency of casting.
- low initial tooling costs, investment casting tools generally have a lower cost than other averaged casting processes.
Investment Casting Process
Shell Making(slurry coating)
Baking & Casting
1. Create a wax pattern
The process replicates wax patterns as same as the finished part by injecting wax into a metal injection die.
2. Wax Assembly
The next step is to assemble the wax pattern onto the gate and runner to improve production efficiency.
3. Create the mold shell and set and dry
To build a firm and solid ceramic shell, the finished tree is dipped into a ceramic slurry with a couple of layers. Some parts require four and a half layers of coating, some require five or six layers depending on the size and shape of the parts.
The wax inside is melted away by steam autoclave.
After dewaxing, the high-temperature operation also strengthens the shell and increase stability, which minimizes the possibility of problem during pouring.
5. Baking and Casting
The molten metal is poured into the pre-heated mold cavity.
Waiting for the mold cools to the room temperature and fully solidify.
7. Shell Removal
The shell material is removed through processes of hammer knockout and vibration.
8. Cut Off
The individual parts are cut off from the gating and runner system.