Introduction of lost-wax casting (Investment casting)

27 4 月, 2020

Introduction of lost-wax casting (Investment casting)

Unitedparts Supplies is proud of providing kinds of OEM custom parts manufacturing service, such as metal stamping, laser cutting, casting (die-casting/lost wax casting/gravity casting), forging, machining, plastic injection, and assembly.

In order to let more people understand each manufacturing service, the process, the advantage and disadvantage etc. We want to introduce these manufacturing process, and if you have some questions, please feel free to contact us.


What is lost wax casting?


The originally English of lost wax casting called investment casting; however, the manufacturing process of dewaxing, it is also known as lost wax casting.


There are two major categories of lost wax casting: solid mold and ceramic shell mold. The ceramic shell mold is a modified method from solid mold. Most of foundries apply for this method already.


Lost wax casting is widely used in industry machinery and equipment, valves, pump, injection engines, gas turbines, measuring instrument, aircraft parts, internal combustion engines, vehicles, food machinery, printing machinery, paper machinery, compressors, sewing machines, steam turbines, weapons, business machines, and other machine parts.


The material of the lost wax casting method is made of refractory slurry (such as silicic acid or silicone rubber), binder and other materials to make slurry liquid and mix with zircon sand and mulgrain sand are sequentially covered in the wax tree outside after repeating several times of dipping slurry, fluid sand and drying to form a layer of similar ceramic shell, after the formation of the so-called ceramic shell mold, so casting alloy steel, super alloy and other high-temperature high-precision casting method, known as ceramic shell mold lost wax casting method.


The Benefits of Lost-Wax investment casting


  1. Investment casting can apply any material and more flexible of production capacity. Casting material without any restrictions, such as aluminum, magnesium alloy, titanium alloy, copper alloy, all kinds of steel, cobalt and nickel-based heat-resistant alloy, hard materials.
  2. Investment casting can produce and make for thin-wall, complex shape, delicate floral form, multi-working procedure, difficult-to-machine material, near net-shapes and several components become one piece.
  3. Investment can save material waste and mass production.
  4. Investment casting can offer the maximum of casting limits length is 700mm, easy to make the length of 200mm or less. The maximum weight is about 100 kg, but generally is under 10 kg.
  5. Compare with other casting method, investment casting can achieve the purpose of short working time and low cost which doesn’t need many working procedure, large mechanical process, low productivity and waste lots of material in order to bring high cost components.
  6. Investment casting can achieve such as complex components can be casted holes, pitch, groove, teeth, notched, thin sharp edge and other forms. Due to fine dimensional accuracy, more than 90% no longer need to be processed such as milling, turning, boring.


The Process of Lost-Wax investment casting


All of our process from casting wax injection to finish are all with strictly inspection before be delivered.

1. Manufacturing of die as per customer’s drawing specifications with close tolerances

2. Preparation of disposable wax patterns by injection moulding & inspection of wax patterns

3. Assembling of wax patterns on runner to form an asssembly

4. Building a ceramic shell by alternate dipping of the assembly in a ceramic slurry and stuccoing under controlled conditions of humidity and temperature

5. Drying molten metal in the sintered shell, fetting, heat treatment and cleaning of the casting

6. Inspection and testing which includes 100% visual inspection, dimensional checks, non-destructive examinations