Gravity Die Casting is a permanent mold casting technique in which the molten metal is poured into the mold using a container or ladle. The only force acting on the mold cavity is gravity, and filling may be regulated by tilting the die. Sand cores can be used to include undercuts and cavities into component forms. Due to quick solidification, this method provides a superior surface finish than sand casting as well as improved mechanical qualities.
Additionally, compared to aluminum sand casting, this method offers a greater casting rate. However, metal molds are more expensive than sand. The potential of low gas porosity and the attainment of tiny particle sizes are benefits of this method.
Gravity die casting typically results in higher-quality products than sand casting because it requires less finishing and fettling. In comparison to sand casting, the gravity die casting production technique often produces tooling at a lower cost.
Gravity die casting offers a large number of advantages. Some of them include the following:
• Outstanding dimensional accuracy
• Flawless cast surfaces
• Intricate forms may be cast with thinner walls
• Cast-in inserts might include threads, heating devices, and high-strength surfaces
• Reduction or elimination of secondary machining
• Longer manufacturing runs are conceivable due to the possibility of high production rates
• Greater tensile strength than with sand casting.
Aluminum Gravity Die Casting
The development of the mold using CNC machines is the first step in the aluminium gravity die-casting process, like other casting methods. Then, using either manual labour or gravity casting equipment, pour the melted aluminium ingots into the permanent moulds to fill the void. The aluminium alloy should next be cooled for a period to solidify. Finally, remove the flash from the aluminium gravity die casting blanks after removing them from the mold and perform any necessary post operations, such as shot blasting or machining.
A356-T6 Aluminum Gravity Die Casting Alloy
An aluminium alloy called A356 is made specifically for gravity die casting. It is appropriate for usage in aircraft, pump housings, impellers, high-velocity blowers, and other structural castings that need high strength because A356 cast aluminium alloy has outstanding casting and machining performance. This light alloy, which offers lightweight, pressure tightness, and excellent mechanical qualities, is often utilized to create complicated aluminium castings. A356 is occasionally used in place of 6061 aluminium.
Mechanical Properties at a Glance
• Elongation at Break: 3-6%
• Fatigue Strength: 50-90 MPa
• Shear Modulus: 26 GPa
• Ultimate Tensile Strength: 160-270 MPa
• Yield Tensile Strength: 83-200 MPa
• Melting Onset: 570℃
• Density: 2.6 g/cm³.
T6 heat treatment is advised after gravity die casting to enhance the mechanical qualities of A356 aluminium castings. A356 castings might have improvements in hardness, tensile strength, and ductility of 106%, 106%, and 214%, respectively.
Advantages of aluminium gravity die casting
• The surface finish and tolerances are both good
• When manufacturing quantities are relatively modest or when heat treatment is required to enhance the mechanical qualities, gravity die casting is a competitive casting technique.
• In comparison to sand casting, this casting technique provides superior tolerances and surface finish. But compared to sand casting, the tooling costs are a little higher
• Gravity die casting allows for the cost-effective production of tiny and medium-sized quantities of products with intricate interior forms.
Steps Involved in the Aluminium Gravity Die Casting
There are various processes in the aluminium die-casting process, especially if you need specialized parts for your applications. This is how it goes:
• Review of the customer's 2D drawing and the part's 3D CAD model
• Creating a 3D model of the component and getting client approval on the prototype
• Making reusable metal moulds and sand cores
• Finishing the PPAP procedure
• Die-cast aluminium alloys are melted and poured into automated gravity die-casting equipment.
• Removing the gate and allowing the cast to cool and solidify
• Heat treatment to enhance the mechanical qualities of the castings
• Shot-blasting to clean off dirt and sand down uneven surfaces
• CNC machining to improve the components.
This is the best method for producing accurate, efficient components for any industry. Automotive body parts manufacturers carefully monitor every step of the process and quality-test the finished product to ensure the highest level of client satisfaction.
Here is a look at some of the major components achieved through aluminium gravity die casting:
• Jigs & Fixtures & Foundry Machinery
• Leak Testing Machines & Thin Wall Leak proof Castings
• Radiography Quality Castings for High RPM
• Butterfly Valve Body for Material Handling
• Diesel Engine Parts, Crank Cases, and Cylinder Heads
• High Voltage Electric Parts and Two Wheelers Proto Castings
• GDC Dies & Pattern Equipment
• Die Casting Machines and Core Shooter Machines
• Heavy Commercial Vehicle Intercoolers
• Light Commercial Vehicle Intercoolers
• Fully Finished Precision Machined Castings
What Castings Can Replace Gravity Die Castings?
Aluminium die casting is an excellent substitute for gravity die casting when producing complicated pieces in big quantities. Sand casting is a viable alternative. However, because sand casting parts require additional post-production machining, they might occasionally be more expensive. HPDC (high-pressure die casting) is an excellent substitute for producing more exact parts. Caparo is an expert in the production of aluminium die casting and has more than 30 years of expertise in this field. Please feel free to contact the company if you need precise die-casting services for your project.
Concluding Remarks
The Caparo Group has been providing a full range of solutions from the idea to the manufacturing stage for more than 30 years as a producer of intricate aluminium precision casting. Caparo has a history of providing dependable, effective, and high-quality aluminium casting solutions to clients worldwide, and it has consistently led the industry in terms of technical know-how, innovation, and competence.
Caparo has built a top-notch aluminium foundry to create complex aluminium castings using gravity die casting and high-pressure die casting techniques. The company’s 850 devoted staff, in-depth metallurgical expertise, design and technical prowess, and use of contemporary technologies all work together to make it a chosen partner for its clients. The division has installed 7 high-pressure die-casting Buhler machines ranging from 250T to 1600T and each machine has a holding furnace and Jet cooling facilities. The facility has provisions for partial squeeze technology and vacuum die casting.