Squeeze casting
Introduction
Squeeze casting as liquid-metal forging, is a process by which molten metal solidifies under pressure within closed dies positioned between the plates of a hydraulic press.The applied pressure and instant contact of the molten metal with the die surface produce a rapid heat transfer condition that yields a pore-free fine-grain casting with mechanical properties approaching those of a wrought product. The squeeze casting process is easily automated to produce near-net to net shape high-quality components.
Process Characteristic
The squeeze casting process, combining the advantages of the casting and forging processes, has been widely used to produce quality castings. Because of the high pressure applied during solidification, porosities caused by both gas and shrinkage can be prevented or eliminated. The cooling rate of the casting can be increased by applying high pressure during solidification, since that contact between the casting and the die is improved by pressurization, which results in the foundation of fine-grained structures.
The Advantages
1) Good roughness like die casting & precision casting;
2) Parts with high-accuracy and tolerance like die casting & precision casting;
3) No more material costs and extra machining, much better than forging;
4) Can be T6 treatment, better than die casting, and like forging;
5) Parts with High Sealing Property as with almost no pores;
6) High mechanical property like forging, better than investment casting or sand casting;
Comparison between different processes:
Items | Squeeze casting | Forging | Investment Casting | High Pressure Casting | Low Pressure Casting |
Surface | Fine | Fine | Bad | Fine | Medium |
Roughness | Ra3.2~1.6 | Ra3.2~1.6 | Ra6.3~3.2 | Ra3.2~1.6 | Ra6.3~3.2 |
Inside | Fine Grain & Compact microstructure | Fine Grain & Compact microstructure | Coarse grain&Loosen microstructure | Inhomogeneous grain &Loosen microstructure | Coarse grain&Loosen microstructure |
Heat Treatment | T6 | T6 | T6 | Can't do T6 | T6 |
Structure Level | Complex Structure | Simple Structure | Complex Structure | Complex Structure | Simple Structure |
Forming Accuracy | High | Medium | Medium | High | Low |
Extra Machining | Minor | More | More | Minor | More |
Production Efficiency | High | Low | Low | High | Low |
Mechanical Properties | Same or close to forging | Highest | Medium | Low | Low |
Mechanical property
After T6, the mechanical property of squeeze casting parts could be very high.
Mechanical property comparison of the squeeze casting parts from different materials:
Material Lot# | Tensile Strength Mpa | Yeild Strength Mpa | Hardness HB | Elongation % |
AlSi9Mg | 240 | 160 | 80 | 3 |
A356 | 260 | 180 | 80 | 5 |
A356.2 | 290 | 220 | 90 | 6 |
Al-Ti alloy | 320 | 260 | 100 | 8 |
S319 | 340 | 290 | 110 | 8 |
SAMPLE TEST REPORT
Wide application
With the current emphasis on reducing materials consumption through virtually net shape processing and the demand for higher-strength parts for weight savings, the emergence of squeeze casting as a production process has given materials and process engineers a new alternative to the traditional approaches of casting and forging. By pressurizing liquid metals while they solidify, near-net shapes can be achieved in sound, fully dense castings.
Squeeze casting is simple and economical, efficient in its use of raw material, and has excellent potential for automated operation at high rates of production. The process generates the highest mechanical properties attainable in a cast product. The microstructural refinement and integrity of squeeze cast products are desirable for many critical applications.
Application | Parts |
Automobile Stressed Parts | Automobile Piston, Al-alloy or Almag wheel hub, Beam(cross beam), Knuckle, Lower arm, Brake caliper, Engine mounting, gearbox, Air compressor connectin rod |
Pressure parts/Air tight Parts | Air conditioning compressor turbine disk, Cylinder, Front and rear cover, Steering valve housing, Oil Pump, Manifold, Fuel distribution pipe, Brake block, Clutch cylinder |
Wear resistance parts | Shift Fork, Pump Casing, Rocker arms, Caterpillar board, Air compressor piston and swashplate, Aluminum composite brake hub, |
Motorcycle Stressed parts | Al-alloy or Almag wheel hub, Upper and lower connecting plate, Gearbox housing, Rear hanger, Crank, Frame body, Joint, Frame joint, Direction axis |
Motorcycle pressure and wear parts | Aluminum piston, Shock absorber, Disc brake pump body |
Electrical Parts/Power Parts | Disk drive housing,Electrical spindle bushing, Electrical compression ring, Sonar shel, Hotplate, Computer parts, Rotors, Crimping clamp, Suspension Clamp, Parralle groove clamp |
New energy vehicles | Electric automobile parts, Hybrid Power automobile parts, Bumpers, Body shell, Body framing |
Advanced field | Military parts, Aerospace accessories, Aircraft Accessories, Optical frame shell, Medical equipments accessories, Fitness equipment accessories |
Others | Marine Propellers, Pneumatic instrument housing, Pressure cooker and cooker equipments parts, Furniture accessories, Valve body, Valve Accessories, Garden tool parts, Fan blades, ect. |