Investment casting (lost wax casting) is suitable for the production of parts with complex shapes, high precision and difficult-to-cut materials, especially for materials such as high-temperature alloys, stainless steel, aluminum alloys, and titanium alloys. The material selection of investment castings needs to comprehensively consider factors such as the use environment, mechanical properties, processing difficulty, cost, and adaptability of the investment casting process. The following analysis is based on common material types, typical application scenarios, selection principles, and precautions to help rationally select materials:
High-temperature alloy parts (such as aircraft engine turbine blades):
It is necessary to select high-temperature resistant and oxidation-resistant alloys (such as nickel-based high-temperature alloys), and use the near-net-shape forming ability of investment casting to reduce subsequent processing, while ensuring the strength and stability of the material at high temperatures.
1. Performance advantages:
Excellent high-temperature strength (temperature resistance can reach more than 1100°C), oxidation resistance, and thermal corrosion resistance.
Suitable for complex cooling structures (such as turbine blade air film holes), near-net-shape forming is achieved through investment casting, and machining is reduced.
2. Application scenarios:
Aerospace: engine turbine blades, combustion chambers, and guides.
Energy and power: gas turbine blades, high-temperature furnace tubes.
3. Key points of the process:
Vacuum melting is required to avoid alloy oxidation, and yttrium oxide ceramic shells are used (resistant to high melting point alloy erosion).
The shrinkage rate is high (1.5%~2.5%), and the mold design needs to be accurately compensated.
Stainless steel parts (such as medical devices, valve bodies):
Corrosion-resistant stainless steel (such as 316L, 17-4PH) is preferred, and the high-precision surface of investment casting is used to reduce the polishing process to meet medical-grade surface requirements.
1. Performance advantages:
Excellent corrosion resistance, comprehensive mechanical properties and surface finish (Ra≤6.3μm), suitable for precision parts.
Martensitic stainless steel can be strengthened by heat treatment (such as 17-4PH after aging treatment, the hardness reaches HRC38-44).
2. Application scenarios:
Medical devices: surgical instruments, artificial joints (biocompatibility is required, such as 316L).
Industrial valves: valve body, pump housing (corrosion resistance requirements, such as 316L).
Food machinery: pipe fittings, reactor parts (sanitary surface).
3. Key points of the process:
Avoid carbide precipitation (such as 304 stainless steel needs to control the solution treatment temperature) to prevent intergranular corrosion.
Poor thermal conductivity, thick-walled parts are prone to shrinkage, and the pouring and riser design needs to be optimized.
Aluminum alloy parts (such as aerospace structural parts):
Select high-strength aluminum alloys (such as A356, 2024), and use the thin-walled part forming ability of investment casting (minimum wall thickness can reach 0.5mm) to achieve lightweight design.
1. Performance advantages:
Lightweight (density about 2.7g/cm³), high specific strength, suitable for thin-walled parts (minimum wall thickness 0.5mm).
Good thermal conductivity, suitable for heat dissipation parts (such as electronic device housings).
2. Application scenarios:
Aerospace: structural parts, engine compartment parts (such as A356-T6).
Automotive industry: turbocharger housing, suspension system parts.
Consumer electronics: precision housing (such as drone rack).
3. Key points of the process:
Easy to inhale and form pores, and the melting process needs to be strictly controlled (such as degassing by introducing inert gas).
The shrinkage rate is moderate (0.8%~1.2%), and the riser needs to be reasonably set for shrinkage.
Titanium alloy parts (such as aviation fasteners, artificial joints):
Use investment casting to solve the problem of difficult cutting and high cost of titanium alloys, while ensuring the biocompatibility of parts (such as Ti-6Al-4V).
1. Performance advantages:
High specific strength (strength is close to stainless steel, and density is only 60% of it), corrosion resistance, and excellent biocompatibility.
Suitable for high-load and highly corrosive environments (such as marine engineering, medical implants).
2. Application scenarios:
Aerospace: fasteners, landing gear parts (TC4).
Medical devices: artificial joints, dental implants (TC4ELI, low-gap elements).
Chemical equipment: corrosion-resistant valves, pump impellers (TA2).
3. Key points of the process:
High melting point (about 1668℃), vacuum arc melting and yttria ceramic shell are required.
High activity, easy to react with the shell to form a surface contamination layer (α embrittlement layer), which needs to be removed by machining later.
Copper alloy
1. Performance advantages:
Good wear resistance (such as tin bronze for bearings), seawater corrosion resistance (such as aluminum bronze for ship parts).
Excellent thermal conductivity, suitable for heat exchanger components.
2. Application scenarios:
Mechanical manufacturing: shaft sleeves, worm gears (tin bronze).
Shipbuilding industry: propellers, valves (aluminum bronze).
3. Key points of the process:
Aluminum bronze is easy to oxidize, and a bottom pouring system is required to avoid turbulent air entrainment.
The shrinkage rate is low (0.7%~1.0%), which can reduce the size of the riser.
successful cases
Choose the plan that suits you best.
Alloy Steel Investment Casting
Alloy steel investment casting components are typically used in industries where high strength, wear resistance, and corrosion resistance are required.
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Lost Wax Casting Parts
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Investment Casting Metal Parts
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