Custom Investment Casting Parts

Investment casting (lost-wax casting) produces near-net-shape metal components with complex geometries, tight dimensional tolerances, and smooth surface finishes. This manufacturing process reduces or eliminates the need for secondary machining, making it cost-effective for medium to high-volume production of intricate structural and mechanical parts.

Operational Capabilities & Engineering Limits
• Weight Range: 0.05 kg to 80 kg (0.11 lbs to 176 lbs) per part
• Minimum Wall Thickness: 1.5 mm (0.060 in) for silica sol process; 3.0 mm (0.120 in) for water glass process
• Linear Dimensional Tolerances: ISO 8062-3 Grade DCTG 4 to DCTG 6 (Silica Sol); DCTG 7 to DCTG 9 (Water Glass)
• As-Cast Surface Roughness:
Silica Sol Process: Ra 3.2 µm – Ra 6.3 µm (125 – 250 µin)
Water Glass Process: Ra 6.3 µm – Ra 12.5 µm (250 – 500 µin
• Annual Production Capacity: Up to 15,000 metric tons combined output

Process Selection Guide for Buyers

The foundry operates dual-process investment casting lines: Silica Sol for high-precision, corrosion-resistant parts, and Water Glass for structural carbon steel components.

Process Flow
• Aluminum Tooling
• Wax Injection
• Tree Assembly
• Ceramic Slurry Dipping
• Dewaxing & Firing
• Pouring & Cooling
• Shakeout & Cut-Off
• Final Inspection

Detailed Step-by-Step Execution
• Tooling & Die Fabrication: CNC-machined aluminum dies (6061/7075 alloy) are produced with shrink allowances (typically 1.5%–2.5%) factored into the CAD model based on alloy solidification dynamics.
• Pattern Injection: Temperature-controlled wax is injected into the aluminum die under pressure (2.0–4.0 MPa) to create an exact replica of the target component.
• Pattern Assembly: Individual wax patterns are gating-engineered and attached to a central wax runner (tree structure) to optimize metal flow and feeding during solidification.
• Shell Building:
Silica Sol: The pattern tree is dipped into a colloidal silica slurry and coated with zircon sand (primary coats) followed by mullite sand (backup coats). 5 to 7 layers are applied with strict humidity control (55% ± 5% RH) between coats.
Water Glass: The tree is dipped into a sodium silicate binder slurry and stuccoed with quartz sand, hardened in an ammonium chloride or aluminum sulfate bath (4 to 6 coats).
• Dewaxing & Autoclave: The shell assembly is placed in a high-pressure steam autoclave (0.6–0.8 MPa, 160°C–175°C) to rapidly melt and evacuate the wax without cracking the ceramic shell.
• High-Temperature Firing: Ceramic shells are sintered in a rotary or batch furnace at 950°C to 1150°C for 45–90 minutes to burn off residual hydrocarbons and achieve structural strength.
• Melting & Pouring: Induction furnaces melt certified raw ingots. Molten metal is slag-skimmed, spectrographically analyzed, and poured into preheated molds at temperatures ranging from 1450°C to 1680°C depending on the alloy.
• Knockout & Cut-Off: Solidified shells are broken via pneumatic hammers or high-pressure water jets. Parts are severed from the sprue using abrasive cut-off wheels.
• Grinding & Shot Blasting: Gating stubs are ground flush, and parts are blasted with stainless steel shot or alumina grit to uniform surface texture.

We process a comprehensive spectrum of ferrous and non-ferrous metals according to ASTM, AISI, DIN, EN, and JIS standards. Chemical composition validation via optical emission spectroscopy (OES) is performed on every heat prior to pouring.

Alloy Specification Matrix

Investment cast parts serve critical functional roles across heavy industry, fluid control, and power equipment:

Application Engine Mapping

While investment casting provides tight near-net shapes, high-precision interface surfaces require secondary CNC operations.

Operation Sequence
Raw Casting → In-House CNC Machining → Heat Treatment → Surface Finishing

In-House Machining Capabilities
• CNC Turning: Diameters up to 500 mm; positional accuracy within ±0.005 mm.
• 4-Axis & 5-Axis Milling Centers: Complex surface profiling, tight-tolerance bore alignment (H7 fit), and precise face flatness (<0.01 mm).
• Threading: Metric, NPT, BSPP, and UNC internal/external thread cutting.

Heat Treatment Processing
• Solution Annealing: 1040°C–1120°C followed by rapid water quench for austenitic stainless steels (restores corrosion resistance and homogenizes structure).
• Normalizing & Stress Relieving: 850°C–900°C air cooling to homogenize grain structure in carbon and alloy steels prior to machining.
• Quenching & Tempering (Q&T): Hardening in oil/water followed by tempering to achieve targeted HRC values (e.g., 28–34 HRC or 45–52 HRC).
• Age Hardening: H900, H1150 conditions for 17-4PH stainless steel to increase tensile strength.

Surface Treatment Options
• Electropolishing (Ra < 0.4 µm for sanitary applications)
• Passivation (ASTM A967 compliance)
• Zinc Plating / Phosphate Coating / E-Coating
• Black Oxide Coating
• Powder Coating & Liquid Painting

Quality assurance begins with raw material verification and continues through post-machining dimensional audits. Every shipment is accompanied by an EN 10204 3.1 Inspection Certificate.

Quality Assurance Verification Matrix

We produce custom components exclusively from customer-supplied technical drawings and specifications.

Project Execution Timeline

Engineering Workflow Details
• Design for Manufacturability (DFM) Review: Engineering evaluates wall thickness transitions, thermal mass concentration, parting line locations, and draft requirements prior to tool cutting.
• Solidification Simulation: Anycasting / MAGMASOFT simulation software models molten metal velocity, cooling curves, and shrinkage tendency to position risers and gates, eliminating internal porosity before cutting steel.
• Prototyping Options:
Quick-Turn SLA/3D Printed Wax Patterns: 7–10 days for physical functional prototypes without hard tooling.
Hard Aluminum Tooling: 21–28 days for production-grade T1 samples.
• First Article Inspection Report (FAIR): Submitted with full dimensional layout (CMM data), chemical composition analysis, mechanical test data, and material certifications.

To receive an accurate commercial proposal and technical review within 24 to 48 hours, please include the following data in your inquiry:

Engineering Drawings:
• 3D CAD Model: STEP (.stp), IGES (.igs), or SolidWorks (.sldprt) file formats.
• 2D Drawing: PDF format with critical tolerances, geometric dimensioning & tolerancing (GD&T), surface finish expectations, and machining callouts.

Material Specifications: Exact material grade (e.g., ASTM A351 CF8M, AISI 4140) or required mechanical parameters.

Order Volumes: Estimated Annual Usage (EAU) and initial pilot batch quantities.

Heat Treatment & Surface Finish: Hardness requirements, passivation, plating, or painting specifications.

Quality & Inspection Scope: Required NDT coverage (e.g., 100% PT, 5% X-ray sampling), pressure testing requirements (bar/PSI), and specific certificate needs (EN 10204 3.1 / 3.2).

Packaging Requirements: Anti-rust VCI packaging, individual box packaging, or standard export palletization.