Precision casting process advantages
Fast
Fast speed, low cost, 2-3 days to get the disappearing mould, to meet the business needs of multi-species, small batch.
Excellent
Wax moulds with complex spatial structure can be printed, and the dimensional accuracy is close to that of moulds.
Net
Only 0.05% ash residue, no heavy metal elements, no pollution of castings.
Precision
The surface quality of the mould is good, with strong expression of details. After processing the surface roughness up to Ra1.6, the smallest print size is only 0.3mm.
When do you need SLA fast precision casting?
☑ Process design optimisation
☑ Urgent delivery
☑ Small quantity (less than 50 pieces), when the cost of making moulds is high
☑ Special structure, unable to open the mould
☑ Test pieces, prototype verification
Casting process details
Ⅰ. Mould making
Pre-processing software's shell extraction function, the mould is processed into a hollow structure: greatly reducing the consumption of resin raw materials, saving a lot of cost; basically eliminates the expansion of the resin in the post-processing process; greatly reducing the amount of residual ash out of the mould step
3D printed moulds: moulds can be produced quickly, regardless of complexity. Eliminates the need for a moulding process, saving a great deal of time and expense.
Required software: Polydevs pre-processing software from Unitech.
Polydevs pre-processing software allows you to customise the wall thickness of the extracted shells, the length and width of the internal support arms, the position of the discharge holes can be freely selected to place them, and the lightweight processing avoids the problem of expanding the shells during dewaxing.
Polydevs pre-processing software fromUniontech
Required equipment:Uniontech SLA 3D printer Lite600
Material:Somos photosensitive resin 111222, Element
Has a very low ash content. And the surface people ash is very easy to be cleaned, and at the same time has a low viscosity, dimensional stability, smooth surface of parts, easy surface treatment, product stability and so on.
Ⅱ.mould pre-processing and assembly of trees
SLA printed moulds can be directly "welded" to the sprue with wax and assembled like normal wax moulds.
Considering the way of removing the SLA mould, the design of the gate and runner can be bigger than the traditional wax mould, which can help the air to enter and burn the mould.
Ⅲ.Shell making
Before hanging the first layer of paste, when cleaning the wax tree, pay attention to see if there are any air bubbles appearing. If there are, it means that the mould is not well sealed. Avoid damage to the wax tree by buoyancy when immersing it in the slurry. In order to enhance the strength of the mould shell, consider making one more layer of shell or using reinforcement.
Ⅳ.Dewaxing
Scald through the ventilation holes before roasting to facilitate gas convection during roasting.
Ⅴ. Roasting
Adequate air into the high-temperature roasting, maintain the temperature at 800-1100 degrees for two hours (according to the size of the part, the appropriate extension of time)
SLA prototype used Somos casting speciality resins (Somos @ 11122, Somos @ Element) 50 ~ 60 ℃ when the beginning of softening, more than 300 ℃, the molecular structure of the resin began to collapse, reaching 600 ℃, the resin material combustion decomposition into carbon dioxide, water and a small amount of residue. Completely burned destabilisation temperature at about 800 ℃.
Ⅶ.remove the ash
Ash residue will affect the surface quality of the casting and cause internal defects.
Ⅶ. preheating and pouring
Plug the ventilation holes with ceramic rods, refractory clay and other materials before preheating
Finished Product Show
The application of 3D printing technology in precision casting process is one of the important directions of technology development in precision casting industry. By combining 3D printing and precision casting of their respective advantages, can break through the industry's original small batch moulding high cost, modelling limitations and other pain points. At present the application of 3D printing process to production has become the trend of precision casting industry. Whether it is 3D printing wax mould, 3D printing ceramic core or 3D printing mother mould and other applications will greatly strengthen the market competitiveness of precision casting company.
