Consumable Pattern Ceramic Molding
Our Process
Waukesha’s Consumable Pattern Ceramic Molding is best described as a hybrid between investment casting and lost foam casting, using elements of each. The process begins with a consumable pattern made from one of several material types:
- Styrofoam (CNC milled or blown)
- Polymethyl methacrylate acrylic (PMMA, 3D printed)
- Stereolithography (SLA, 3D printed)
These patterns are alternately coated in ceramic slurry and stucco, with drying between each application. Once the required number of layers is built up, the foam is evacuated and the shell is fired to develop maximum strength. The resulting ceramic molds are cleaned, inspected, and buried in sand prior to metal pouring.
The end result is a durable ceramic mold capable of producing castings with high dimensional accuracy and complex geometry.
Key Waukesha Advantages
- Ideal for very complex castings that would often require cores
- High dimensional accuracy with minimal draft angles
- Excellent near-net surface finish, reducing the need for machining
- Applicable for both high and low production volumes, depending on pattern type
- Versatile process compatible with multiple pattern materials
- Wide alloy selection, including Waukesha’s proprietary specialty metals
Waukesha Investment Casting Capabilities
- Part weight range: Approximately 5 lbs to 2,500 lbs (depending on part envelope)
- Section sizes: 0.250″ to 14″
- Surface finish: Approximately 300 RMS, depending on part size and processing
Please contact us for specific part and size feasibility.
Pattern Material Options
Waukesha Foundry supports four consumable pattern types for ceramic molding, making the process highly adaptable across a wide range of part designs and lead times:
- Machined Foam
- Blown Foam
- 3D Printed PMMA
- 3D Printed SLA
Each pattern type is selected based on project requirements such as lead time, geometry, and production volume. All patterns are coated in ceramic slurry and stucco to form a shell. Once shell building is complete, the patterns are evacuated in a furnace, fired, and buried in bonded sand before pouring. Shells are poured at ambient temperature.
3D printed PMMA and SLA patterns are well-suited for rapid prototyping and short-run production. These pattern options eliminate the need for hard tooling and help reduce turnaround time without compromising on part integrity or material choice.
Advantages Over Investment or Lost Foam Casting
- More versatile pattern material options
- Accommodates a wider range of part sizes and geometries
- Higher mold strength and better dimensional stability
Disadvantages Compared to Investment or Lost Foam Casting
- Surface finish typically limited to 300 RMS, compared to 125 RMS for investment
- Tolerances are not as tight as those achieved with investment or lost foam processes
// Pattern Method Comparison Table
How Our Process Compares
Waukesha Foundry’s Consumable Pattern Ceramic Molding process offers multiple patterning methods to align with different project needs, whether it’s rapid prototyping, low-volume runs, or high-volume production. The chart below summarizes how these pattern types compare to traditional methods.
| Manufacturing Process | Lead Time | Part Size | Volume Suitability | Tooling Cost | Per-Part Cost | Applications | Limitations |
|---|---|---|---|---|---|---|---|
| Machined Foam Pattern, Ceramic Shell | 4–8 weeks | 5 to 2500 lbs | Low | $ | $$ | Quick lead time for low-volume, complex designs | Thin section sizes may not be possible |
| Blown Foam Pattern, Ceramic Shell | 20–26 weeks | 5 to 500 lbs | Very High | $$$$$ | $$ | Cost-effective for high-volume production | High tooling cost and long lead time |
| 3D Printed Pattern, Ceramic Shell | 6–8 weeks | 5 to 2500 lbs | Low | $$ | $$ | Rapid prototyping or complex geometries | Higher cost compared to foam patterns |
// Process Comparison Summary Table
How It Compares to Other Casting Methods
Waukesha’s Consumable Pattern Ceramic Molding process combines the strengths of both investment and lost foam casting while addressing some of their limitations. The summary below provides a high-level comparison of each method’s capabilities and trade-offs.
| Process | Advantages | Limitations |
|---|---|---|
| Consumable Pattern Ceramic Molding | Multiple pattern types, higher mold strength, adaptable to various part sizes | Max 300 RMS surface finish, wider tolerances than investment |
| Investment Casting (Low-Cost Country Sourcing) | Suitable for high volumes of smaller parts, re-usable wax patterns | Mold must be poured hot, limited to smaller part sizes |
| Lost Foam (or Lost Wax Casting) | Similar to investment but with foam patterns, fewer cores needed | Foam is not removed prior to pour; quality can be impacted by residue |
Investment Casting (Low-Cost Country Sourcing)
Investment Casting is only applicable for higher volume, smaller weight parts. The process typically uses wax patterns. The pattern is coated in alternating layers of ceramic slurry and stucco, forming a shell around the pattern.
Once the required number of layers is achieved, the pattern is evacuated in an oven and the wax is re-used. The empty shells are then fired at high temperatures and turn into hard ceramic, similar to pottery.
The shells are removed directly from the high temperature oven to be poured red-hot. If they are allowed to cool, cracks may form which would need to be repaired before pouring.
FAQs
What industries use WM3?
As a food-grade alloy that can be used at both low and high temperatures, WM3 is used throughout food, beverage and dairy processing equipment. Its high strength and corrosion-resistant properties also make it a top choice in seawater and desalination applications that often involve high-volume production demands.
How does WM3 compare to nickel-based alloys like WM88?
While both alloys offer resistance to wear in metal-to-metal contact, WM88 is the preferred choice for demanding anti-galling applications. WM3 is typically selected for applications where corrosion resistance, thermal conductivity, and material compatibility are primary considerations, rather than maximum anti-galling performance.
Do you offer custom bar lengths or castings in WM3?
Absolutely. In fact, you can get any Waukesha Metal in the length or casting needed for your application. It’s part of our commitment to helping our customers get the right materials for their production parameters – and where needed, our tooling expertise ensures components are ready for precision performance.
Does WM3 resist galling against stainless steel or Inconel®?
Yes. Our WM3 alloy offers great anti-galling properties for clean processing.
Can I request material testing or performance data for WM3?
Our team of experts will work alongside your engineers to get you everything you need to maximize WM3 performance in your application.