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Frequently Asked Questions

Investment casting is a manufacturing process in which a wax pattern is coated with a refractory ceramic material. Once the ceramic material is hardened, its internal geometry takes the shape of the casting. The wax is melted out and molten metal is poured into the cavity where the wax pattern was. The metal solidifies within the ceramic mold and then the metal casting is broken out. This manufacturing technique is also known as the lost wax process.

Investment casting was in us for casting of religious and fine-arts applications during the 4000 BCE-1540 CE period. It is now clear that the secret behind the intircate motifs and serial production of gold and silver ornaments was the investment casting method. Starting from 1897, the method was being used for dentistry and surgical apparatus production. The starting steps for the modern industrial development of investment casting started in 1907 in Chicago, USA, through the invention of first technological industrial wax. During WW-II, the demand for special alloys and difficult geometry of parts for jet motors and turbines led to the further development of the process, and investment casting entered the industrialization era. Following this majör historical development, investment casting is now the unique method for production of complex shape parts.

Almost any configuration or design can be produced as an investment casting. Investment castings offer more design flexibility over any other manufacturing process. Investment castings excel at reducing the high cost of machine components and weldments.

· Complex shaped parts, not possible or feasible with other methods, may be produced.
· Excellent surface quality and tight tolerances are possible simultaneously.
· The need for secondary-machining is minimised.
· A very diverse range of casting alloys is feasible.
· Irregularities such as burrs and mould release lines are eliminated.
· Precise dimension control and design flexibility is at peak level.
· Part weight reduction and economic alloy consumption possibilities.
· High quality coupled with high mechanical strength
· Possibility to produce low batch-sizes in short durations
· Owing to long mould life-span, excellent repeatability in part production parameters.
· Cost increase due to the non-recyclability of seramik shells and wax models (hence the name lost-wax-method)
· Relatively high cost of raw materials required for the process
· Comparatively higher need for well-educated and experienced labor
· Less recognition of the method in the industry, in comparison to more common production methods

While investment castings are usually more expensive than other casting and production methodds, investment castings greatly reduce the overall cost of a metal component by reducing the amount of machining or welding and material waste that may occur.

Typically, a split cavity aluminum die is manufactured that is the "female" mold from which the "male" wax patterns are produced. Depending on the complexity of the casting, various combinations of aluminum, ceramic or soluble cores may be employed to yield the desired configuration.

Please refer to our website: Quality / Metrology Laboratory / VDG P690 Tolerance Table.

Iron based Alloys
 1) Stainless Steel Alloys

 2) Steel Alloys

     1.1) Austenitic Stainless Steels

     2.1) Carbon Steels

     1.2) Ferritic Stainless Steels

     2.2) Cementation Steels

     1.3) Martensitic Stainless Steels

     2.3) Tempered Steels

     1.4) PH (Precipitation Hardening) Steels

     2.4) Tooling Steels

     1.5) Dublex Stainless Steel

     2.5) Automate Steels

 

     2.6) Spring Steels

Aluminum based Alloys

ASTM F75 CoCrMo Alloy

Copper based Alloys

- 2 units of 2x150 kg double-crucible induction furnaces at 175 tons/month active steel melting capacity
- 3 units of 500 kg, 300 kg ve 100 kg induction furnaces at 35tons/month  active aluminum melting capacity.
- Weight range: 0.5gr to 105 kg steel casting and 10gr to 35 kg Aluminum casting capability for complex parts.

YES. Unimetal offers finished products through in-house operations and organization of tooling production, casting, precision machining, heat treatment and surface treatment.

YES, and dimensional capacity is 500 x 400 x 300 mm. Rapid Prototype process can be implemented which will be a low risk opportunity to prove your design using Investment Casting. This will provide you and your company an Investment Casting for your testing and evaluation. It could also be an excellent solution for your low-quantity orders, without incurring Tooling cost.Often a cast prototype can be produced in 2 weeks.

· MACHINING: Although the latest technology machining equipment makes it possible to produce complex geometry parts, investment casting is always favorable for unit price in terms of high-volume demand and delivery duration. Material consumption and waste is also significantly lower in investment casting. Alloy diversity is much wider in investment casting. And complex geometries that could not be attained in machining are possible with investment casting through the usage of ceramic cores and water-soluble waxes.
· MIM: Tooling costs are significantly higher in MIM. Smaller and less critical parts may well be produced with MIM method, but all sizes and highly critical parts are possible with investment casting, with a more diverse alloy range at lower cost. Low batch-size production is NOT possible with MIM.
· SAND CASTING: The surface quality range of Sand Casting is Ra: 12.5-50.0, whereas investment casting is much finer at Ra: 3.2-6.3 range. Investment casting is the best choice for much tighter tolerance requirements, and allows the casting of complex parts within a wide alloy range.
· FORGING: Complex designs and geometries that are not possible for forging are all possible with investment casting.
· DIE CASTING: Limited alloy range and high tooling cost are the main disadvantages of die casting. Repeatability of injected parts in comparison to original specs is not continuously sustainable. Impurities of the molten metal and lacking the required feding metal during cooling are the shortcomings of the process, causing microstructural and volumetric flaws.

Samples within 2 weeks and upon sample-approval 6-8 weeks for serial production.

Investment casting will yield Ra 3.2 to 6.3, which can be further refined with secondary-machining.

Yes, we can provide solutions for many challenging parts. In fact, investment castings is often the only answer to casting difficult parts economically. Unimetal is an expert in manufacturing parts that would be very costly if at all possible with other methods.

YES, we create high quality, flexible and economical solutions to customer demands from hundreds to hundred thousands peices. Unimetal prides itself in meeting your specific requirements and deadlines.

Typically, we respond to your RFQ with a quotation within 1 week, if the data that we require is supplied timely by customers.

For a clear, precise and timely quotation; we request, if possible:
a. 2D technical drawing
b. 3D model data
c. Casting material / alloy information
d. Yearly demand quantity and delivery lot-size
e. Specific quality requirements / standards