Compared with traditional lost wax casting technology, 3d printing investment casting saves human resources and time and can provide more complex casting models. Therefore, 3d printed casting patterns are increasingly becoming the preferred investment casting solution for metal foundries and professional engineers. In addition to providing better surface finish and precision, 3d printing investment casting also has high quality and consistency in producing small batch casting components. So how do we understand 3d printing investment casting? We can learn some facts from its advantages and applications.
Benefits of Using 3D Printing Investment Casting
For a long time, the limelight of 3d printing investment casting overwhelmed lost wax casting. It does not need to spend plenty of time and money producing models because it uses CAD files to create prototypes. Use sla investment casting technology to print the model directly, with extremely low cost and fast speed.
First of all, 3d printing investment casting reduces the number of assembly parts and produces lighter castings. Strength and durability even surpass traditional metal manufacturing parts. It is necessary to know that lost wax casting takes a long time to design and manufacture wax molds.
Secondly, using 3d printing investment casting to print large-size parts is a perfect choice. Because it can work at once, there is no need to use a small device to print twice as usual. Not only the model-making time is significantly shortened, but also the labor cost is greatly reduced. In other words, the fewer parts, the less bonding work is required.
Finally, 3d printing investment casting technology has higher fault tolerance. In general, the traditional lost wax process takes weeks or months to modify the wax mold. And if something goes wrong while making the prototype, 3d printing investment casting only takes a few days to redesign. This situation also applies when the component fails to meet the expected standard.
Therefore, 3d printing investment casting is far superior to traditional lost wax casting in terms of time, cost, and operability. Adding 3d printing investment casting to your engineering work must be the best choice for your business to develop more vigorously!
3d printed patterns for metal casting
8 Steps of 3D Printing Investment Casting Process
3d printed casting patterns are a direct substitute for traditional casting models, but 3d printing wax for investment casting will not melt like wax molds. When producing metal parts, 3d printing wax for investment casting will burn in the cavity and leave a small number of ashes. So we need to remove it when cleaning the shell cavity. When using 3d printed casting patterns to make ceramic housings, vent holes are usually added to the surface. Doing that is conducive to the calcination of 3d printing investment casting. In addition, to prevent casting defects, 3d printed casting patterns must have an outstanding surface finish and close tolerances. Let’s take a look at what is the process of 3d printing investment casting?
In this case, we divided 3d printing investment casting into eight simple steps.
Step 1:
Select the configuration file in the printer, and then click Print. In addition, there are some things to note: First, when placing the model on the board, choose a direction that does not require support as much as possible. Secondly, use as few fillers and shells as possible. Finally, there should be a certain compensation coefficient between 3d printed casting patterns and actual metal castings. The best value is between 1.007-1.030.
Step 2:
Before starting 3d printing investment casting, we need to make sure that the printing surface is smooth and free of defects and debris. In this step, we recommend two post-treatment methods: spray polishing and dipping.
Step 3:
First, place the part horizontally on the cup, and then connect the part and the cup with a wax stick or sprue. The purpose of this is to ensure that the liquid metal can flow into the parts accurately and smoothly. In addition, we must minimize the bending of circulation channels. Otherwise, it will hinder the flow rate of the liquid. It is best to place smaller wax blocks in weak areas to achieve uniform flow. If there are any holes or gaps, we can use minor cuts to eliminate them.
Step 4:
Immerse the part tree in the ceramic slurry to create the mold. Pay attention to repeated alternation to ensure that liquid is wholly and evenly cover parts. We recommend that you apply at least five coats. For 3d printed casting patterns with a more complex structure, we should apply about eight layers. Pay attention to let the coating dry completely before repeating the work. Eventually, the printed material will evaporate during the burning process, resulting in a ceramic shell used as a casting.
Step 5：
Place the ceramic-coated parts in the furnace. Usually, we use 1100-1200°C firing for 40 to 60 minutes. The time is not certain. It varies with the type of metal and furnace produced. After the printing material is burnt inside, let the ceramic shell cool down completely.
Step 6:
Check the shell. If there is ash or debris inside, rinse immediately. Then put the ceramic shell into the kiln to preheat. Usually, the temperature is 550-1100 °C. Then you can pour the molten metal into the shell. At this time, the liquid rapidly cools and shrinks in the mold cavity. Finally, it is completely solidified into metal parts with excellent precision.
Step 7:
Now, you need to take out the finished part from the ceramic mold. After the part is thoroughly cooled, we can use a water jet or manually separate it from the mold. Don’t forget the sprue on the part. We recommend using an ion cutter to cut them.
Step 8:
To obtain a better finish and prevent corrosion, you can use patina as a protective coating for the parts.
Conclusion
All in all, there are many advantages to using 3d printing investment casting to make molds. Although traditional lost wax casting technology still has a significant market share, 3d printed patterns for metal casting have stronger practicability and lower cost. In the future investment casting industry, 3d printing wax for investment casting will eventually become the mainstream.