What is Investment Casting?
Investment casting, also known as lost-wax casting, is a popular manufacturing process used by many industries now-a-days. It’s a precise way to make wide variety of parts – especially small or intricate ones using wax and ceramic molds. During the process, liquid wax is poured into a reusable master pattern which then becomes encapsulated in ceramic material before it’s fired off with heat. The heat melts away the wax, leaving behind a precise replica of the master pattern used to cast the part in metal. This method results in pieces that are precise to given specifications and usually require little additional machining. Investment casting is regularly utilized for complex parts with thin walls and intricate details, such as medical implants, turbine blades and engine components which could be challenging in other methods.
Processes of Investment Casting:
Step 1: Pattern Creation The first step is, to create the pattern or die of the desired component based on its 3D – model or design. This mold used is typically made of Wax or plaster model. It can be done by many different methods like carving, 3D printing, injection molding.
Step 2: Mold Creation Once the wax pattern is created, it is placed inside a mold. The mold is then filled with a liquid ceramic material by Injection molding, which hardens around the wax pattern.
Step 3: Tree Assembly The Wax pattern are attached to the centre of the wax sprue, forming the shape of a tree with the assembly of the patterns on both sides.
Step 4: Shell Moulding The tree assembly is immersed in to the refractory slurry which form the shell. It is called as Shell molding. Then after some cooling, it is immersed into coating for two to three times called Stucco Coating.
Step 5: Wax removal After sometime, this mold is heated by placing it a kiln which makes the wax or plaster to get melted leaving the hollow cavity of desired shape. After the wax is melt out, it is heated for the mold to get hardened.
Step 6: Mold casting The next step in the process, is to pour the molten metal into the mold cavity. It is usually poured by the method called as Gravity pouring and then its left for cooling.
Step 7: Removal of Shell After the cast gets solidified, the metal casting is removed by breaking the refractory mold. The shell is removed either by breaking it or by knock out.
Step 8: Finishing Operations Finally, the gates and runners are cut from the metal casting and post finishing processes are done for better surface finish and desired dimensional tolerances.
Investment casting is a versatile and precise manufacturing process that can be used to create a wide variety of shapes.
| Investment Casting |
| Requires more time for casting |
| Smooth surface finish and less post operation finishing |
| More cost |
| Able to achieve complex shapes and intricate designs |
| Higher dimensional tolerances |
| Well suited for high precision components. |
| Sand Casting |
| Less Casting time |
| Usually rough finish and requires post operation finish. But it also depends on the type of sand being used. |
| Relatively cheaper and economical |
| Require extra machining process to achieve desired geometry of any size and shape |
| Low Dimensional tolerance |
| Less precise process than investment casting, |
MATERIALS
In Investment Casting, different materials can be used. The kind of material used to generate the casting mainly depends on its application of utilization. Zastata works with variety of material grades, few of them are,
Aluminium
It is one of the best alternatives in many casting procedures due to its properties such as, Corrosion resistance, high thermal and electrical conductivity, mechanical properties, durability at elevated temperatures, etc.
Steel
Steel castings from investment casting usually have layer of chromium oxide which provides high durability. It is also used for its high corrosion resistance, more strength and toughness.
Metal Alloys
Many parts in investment casting are copper based alloys mainly brass, bronze and beryllium-copper. They have great corrosion resistance and resist more against wear. Also, alloys-based nickel, cobalt provides high rigidity and stronger at high temperatures while being a cost-effective option of manufacturers.
Cast Iron
They have high strength, heat resistance and toughness. Suitable for more complex structures that steel which is the reason for its high production cost compared to steel.
Zastata works in variety of other Iron grades like
- Gray Iron Grades [HT150, HT200, HT250, HT300, HT350]
- Ductile Iron Grades [QT400-15, QT400-15, QT400-15, QT450-10, QT500-7, QT500-9]
Some of the Heat treatment processes Zastata provides to enhance material properties and support fully finished product are,
- Normalizing
- Annealing
- Quenching
- Tempering
- Carburizing treatment process.
Zastata also performs premium quality testing procedures such as Non-destructive testing like fluorescent penetration, magnetic particle, radiographic, or other inspections may also be performed. Final dimensional inspections, alloy test results, and NDT are validated authentically with expertise prior to shipment.
The Finishing Processes
Zastata provides some finishing Processes like,
- Polishing, Sanding, Deburring, Grinding, etc.
- Peening & shot blasting – to roughen a smooth surface is required.
- Fettling – to improve surface flatness of the component.
- Painting and Powder coating – to enhance physical wear resistance, prevents corrosion and also improve physical appearances.
Quality Documentation
Zastata has good understanding and experience with Quality documentation like:
- APQP – Advanced Product Quality Planning
- FMEA – Failure Mode Effective Analysis
- PPAP Level 3 – Production Part Approval Process
- SPC – Statistical Process Control
- MSA – Measurement System Analysis
Die Casting Certifications
Zastata chooses manufacturers based on required certifications and product applications. Our manufacturers are certified to:
- ISO 9001:2015 (Quality Management System)
- ISO 14001:2015 (Environmental Management System)
- ISO 45001:2018 (OH & SMS)
- AS9100 Rev C (Aviation, Space and Defence)
- ISO13485:2016 (Medical Devices)
- IATF16949:2016 (Automotive Quality Management System)
OTHER TYPES OF CASTINGS
Whilst Pressure die casting is widely used casting method for high volume production, there are other casting methods which have their merits
OUR MANUFACTURER LOCATIONS
Over the years, Zastata has audited and worked with various die casting manufacturer across India for various casting types. Our pressure die casting company are selected and retained based on their quarterly quality performance on Cost, Delivery, Quality, Communication, Innovation and flexibility.
COUNTRIES WE EXPORT
Over the years, Zastata has audited and worked with various die casting manufacturer across India for various casting types. Our pressure die casting company are selected and retained based on their quarterly quality performance on Cost, Delivery, Quality, Communication, Innovation and flexibility.
UK
USA
AUS
Denmark
Germany
Canada
France
China
INDUSTRIES WE SERVE
Advantages:
- Very complex and intricate designs with thin sections can be casted.
- Suitable for both Ferrous, Non-ferrous materials and wide range of alloys.
- Provide High level of dimensional accuracy as low as 0.0076 mm.
- Smooth surface finish
- Require very less post machining and finishing process.
- Nearly no material waste.
Applications:
- It is used in Aerospace industries for manufacturing complex parts used in blades and Cooling systems.
- Used for manufacturing high accurate Artifacts like sculptures, Jewellery and Medical Equipments.
- Aircraft parts like door frames, Aluminum and steel castings are made using this process.
- Valve parts in pistons and rotors in motors & generators.
It is clear that investment casting is a highly technical process that requires high skill and experience for proper execution. Zastata is your best companion in providing the premium casting services including investment casting, and other casting services.
Zastata exhibits production complex with state-of-the-art casting equipments, and skilled crew of engineers, complimented by a professional technical team. We also pride ourselves on high-quality part manufacturing with fast lead times.
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