Investment Casting Alloys
Precision investment metal alloy casting utilizes numerous types of materials to produce a wide range of part sizes that maintain exceptional accuracy. With a team that is 100% dedicated to quality precision investment casting, Aero Metals delivers high quality investment casted parts that provide outstanding benefits that are extremely reliable.
At Aero Metals, we cater to the challenges of producing advanced quality complex parts. Our investment casting experts have the knowledge and expertise to replicate your complex parts to your exact specifications. We guarantee a level of quality other investment casters simply cannot match.
Contact Aero Metals for more information regarding our technologically advanced investment metal alloy casting methods, or call us at 219-326-1976 and we will gladly answer any precision investment casting questions that you may have. Aero Metals is your premier source for high quality, high-volume investment casting services.
Investment Casting Alloy Material Options
Precision investment castings can be created from an almost limitless variety of investment casting alloys. The metals we work with include but are not limited to the following materials.
- Stainless Steel
- Ductile Iron
- Beryllium Cooper
- Nickel-Based Alloys
- Cobalt-Based Alloys
- Copper-Based Alloys
The Aero Metals Advantage for Precision Investment Casting
There are several reasons to choose Aero Metals as your source for precision investment castings. Our expert team is results driven and provides the following approach to your investment casting needs.
- Engineering centric with a metal casting focus
- Custom design and build your tools in house
- Extensive experience with complex geometries and hard-to-manufacture parts
- Capable of handling high-volume investment castings
- Numerous material options, including ferrous and non-ferrous alloys
- In-house CNC machining capabilities to complete your metal castings
- One-stop shop for investment castings and casting-based assemblies
- Guaranteed consistent quality
- Our team is comprised of highly-skilled, very experienced toolmakers, engineers, foundry and production technicians you won’t find anywhere else.
Precision Investment Casting Cost & Development Design Strategies
At Aero Metals, we will work with you to provide a proven, cost-effective design strategy that takes into consideration all the key factors within your project. Depending on your specifications, we can design your project with cost-reduction in mind allowing for a better understanding of the overall project cost estimates. Additionally, our high volume production requirements can be met with fully automated multiple cavity molds that provide the capabilities to further reduce costs.
Contact us to discuss your project or send us a quick email!
Investment Casting Elements of Cost
The following considerations should be examined before deciding on what type of investment casting option is best for your project. While we like to think that anything is possible, it always comes down to what it costs to produce it.
Wax Injection Tooling
Tooling type in order of least tooling cost but highest piece price are as follows:
- Manual (may require some tool modifications)
- Fully automatic
Wax Injection Tooling Treatment Methods
The greater the number of cavities per mold, the higher the tooling cost, but the lower the piece price. Configurations that do not allow metal cores to be drawn must be treated in one of the following manners:
- Collapsible Cores - Where possible will yield the lowest piece price but a higher tool cost.
- Loose Inserts - Only for low volume parts, but not recommend.
- Soluble Cores - Additional wax injection mold and injection labor required. Higher piece price but maintains tolerance control.
- Pre-formed Ceramic Cores - Expensive for specialized shapes and only used as a last resort.
Multi-piece Wax Assemblies
An acceptable method to use on selected configurations. Tolerance control suffers and piece price goes up.
Effect of Pieces per Tree
Within certain constraints, the more pieces per tree the lower the cost. When possible, a part should be designed so that a single gate can feed it. This will generally allow more pieces per tree and reduce the pour weight.
Where possible parts should be designed so that gates can be placed on flat surfaces rather than curved surfaces.
Gate grinding tolerances in order of increasing cost are as follows:
- .015 inch gate witness
- Flush to cast surface
- Grind to a dimension
- Radial gate removal
- Shot blast (the least cost method)
- Automatic sand blast (tumbling)
- Hand Sand blast (the highest cost method)
Straightening sometimes cannot be avoided and does add to cost. Try not to specify tighter tolerances for flatness, straightness, roundness, etc., than are required. Straightening costs are directly related to the tolerance specified.
Fixed gages such as “go/no-go” are less expensive than gauges with dial indicators. Whenever gauges are used there should be identical gauges for both Aero Metals and the customer.
- Magnetic particle inspection
- Liquid penetrant inspection
- Radiographic inspection
Certification includes chemical and mechanical test reports as well as marking each casting with Heat Codes for tractability.
The Investment Casting Process
Investment casting requires the use of a metal die (usually aluminum), wax, ceramic slurry, furnace, molten metal, and any machines needed for sandblasting, vibratory tumbling (with or without a grinding or polishing media), cutting, and grinding. The investment casting process involves the following steps:
- Pattern Formation – Lost wax casting patterns are created by injecting molten wax into an aluminum alloy die.
- Assembly – Single molds can be created, or tree-like precision investment casting molds can also be created for larger scale production runs.
- Shell Building – The investment castings outer shell casing is built up through dipping the tree-like assembly into ceramic slurry and then immediately coated with sand several times drying between each coat building layers.
- Autoclave Dewaxing – The inner cavity of precision investment casting is then dewaxed using high pressure and steam which forces the wax out of the cavities and leaves a hollow tree-like assembly of ceramic shell.
- Pouring & Solidification – The ceramic cavity is then heated and cured. This prevents heat shock and the ceramic shell from cracking once the liquid metal is poured into the ceramic tree-like shell.
- Ceramic Removal – Once the metal has cooled enough to be handled, the ceramic shell is removed from the tree and its parts by using a high impulse vibratory shaking.
- Sawing/Cutting – Once the ceramic shell has been cleaned off, the cast part(s) are then “cut off” from the tree-like cluster via a radial saw blade, friction band saw, or broken off using nitrogen.
- Post Processing – The part is then further processed which might include gate removal, caustic bath to remove ceramic from pockets, and heat treatment. Secondary machining, which is done in-house, may also be necessary depending on the requirements of the part and customer expectations.
- Finish – The part can be supplied with a standard 125 RMS sand blasted finish, media polished, plated, painted, or coated to fit the commercial application.