How to use metal 3D printing in die-casting molds?

一, The main benefits of metal 3D printing technology that makes die-casting molds possible
1. You can design complicated buildings for free, which goes beyond what traditional crafts can do.
The cooling water channel in classic die-casting molds is made by mechanical processing, which makes it hard to get a uniform layout of complicated surfaces or deep recesses. This can cause problems like local overheating and thermal fatigue cracking of the mold. Metal 3D printing may build conformal cooling channels by stacking materials on top of each other. This lets the cooling liquid directly affect high-temperature locations and improve the temperature distribution on the mold surface. Platinum Technology, for instance, employs BLT-18Ni300 material to make molds for die-casting aluminum alloys. By optimizing the design of the internal flow channels, the cooling efficiency goes up by more than 30%, the mold life is doubled compared to previous methods, and the product yield rate goes up from 85% to 99%.
2. To lower overall expenses, find a balance between light weight and structural strength.
Traditional mold making uses a lot of metal cutting, but only about 30% of the material is used. The heavy mold construction also makes it more expensive to move and maintain. Topology optimization technology is used in metal 3D printing to get rid of unnecessary materials and find the best balance between weight and structural strength. The aluminum alloy die-casting mold shown by Platinum Lite weighs only 27 kg, which is 40% lighter than typical molds. It is also strong enough to work under high temperatures and high pressures. Also, the integrated molding technology of 3D printing cuts down on the number of parts that need to be put together, stops thermal expansion and contraction changes that happen when parts are spliced together, and makes the mold even more stable.
3. Quick iterations and flexible production to speed up the development cycle
Making molds the old-fashioned way takes a long time and a lot of steps, like designing, cutting, welding, and putting them together. It also costs a lot to change the design. Metal 3D printing directly drives manufacturing using digital models, which makes it easy to quickly make prototypes and make improvements over time. For instance, Broadcom Precision uses Huashu High Tech FS273M series equipment to offer full process services for die-casting molds for new energy vehicle battery pack shells. This cuts the development cycle from 45 days in traditional processes to 7 days, lowers the cost of each piece by 60%, and successfully achieves large-scale application with an annual output of 100,000 sets.
二, A major technological advance in metal 3D printing for die-casting molds
1. New materials: making heat resistance and thermal conductivity work better together
Die casting molds must endure the impact of liquid aluminum at elevated temperatures above 600 ℃, necessitating stringent criteria for the material's thermal cracking resistance, wear resistance, and thermal conductivity. Metal 3D printing is now able to use H13 tool steel, MS1 martensitic aged steel, copper alloys, and other materials in stable ways. It has also been able to improve performance through post-processing strengthening technology. For instance, a company made a copper-based composite material that has a hardness of 52HRC and a thermal conductivity of 120W/(m · K) after being treated with laser quenching. This meets the long-term use needs of die-casting molds for aircraft engine blades.
2. Process optimization: working with several lasers and smart parameter control
Manufacturers of printing equipment are always finding ways to get over technological roadblocks to make printing faster and more accurate. The Platinum BLT-S450 can do collaborative printing with eight lasers and has a forming size of 450mm × 450mm × 500mm. The printing speed is 300% quicker than that of single laser devices. An intelligent parameter control system can automatically change laser power, scanning speed, and other settings based on the properties of the material to make sure that the surface quality and interlayer bonding strength are high. For instance, when making die-casting molds for a certain type of car engine cylinder block, the BLT-S450 equipment runs continuously for 7 × 24 hours, cutting the time it takes to print a single mold from 72 hours to 24 hours and keeping the dimensional accuracy within ± 0.05mm.
3. Strengthening after treatment: improving both surface performance and fatigue life
The surface roughness (Ra ≥ 6.3 μm) and internal residual stress of metal 3D printed parts may affect how well the mold works, thus they need to be improved through post-treatment techniques. The most popular technologies right now are:
Heat treatment: Annealing gets rid of internal stress and makes the material stronger;
Sandblasting and polishing: To lower the chance of aluminum sticking, make the surface less rough by lowering the Ra to 0.8 μ m or below.
Laser cladding: Putting a coating on the mold's surface that is resistant to wear to make it last longer.
For instance, a specific company came up with a composite post-treatment procedure for the die-casting mold of new energy vehicle motor shells that has enhanced the mold life from 30,000 times to 120,000 times and cut the cost per piece by 75%.
三, Examples of how the industry works and how it might make money
1. In the area of new energy vehicles, die-casting molds for battery pack shells
A top firm that makes new energy vehicles employs metal 3D printing to make die-casting molds for battery pack shells. The design of a conformal cooling water channel raises the mold temperature uniformity from ± 15 °C to ± 3 °C, cuts the cycle time by 35%, and extends the life of a single mold to more than 80,000 times, which is 40% longer than typical H13 steel molds. Also, the lightweight structure of 3D printing makes molds 50% lighter, makes handling 60% more efficient, and cuts expenses by 45%.
2. In the aerospace field, there is the engine turbine disc forging die.
To make turbine disc forging dies for a certain type of aircraft engine, traditional methods need to weld and put together 100 separate parts, which can take up to 11 months to deliver. After using Optisys' DMLS technology, the mold has been made into a single unit, which cuts the weight by 95% and the delivery time to 2 months. The mold's stiffness has been enhanced by 25% through topology optimization design, which meets the needs of working in high temperatures and high pressures.
3. In the world of consumer electronics, a laptop shell die-casting mold
A big company that makes consumer electronics employs metal 3D printing to make die-casting molds for laptop cases. The conformal cooling water channel lowers product warpage from 0.5% to 0.15%, and the internal lattice structure design cuts the weight by 40% while keeping the strength. The mold is being used on a wide scale, making 500,000 sets a year. The cost per component has gone down by 30% compared to older methods.