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Great potential in 3D printing
Ceramic 3D printing is already successfully establishing itself as a technology of the future. According to the market research company SmarTech, the industry is expected to generate annual sales of 4.8 billion US dollars by 2030. Every year, new fields of application are added in areas such as process engineering, analytics and sensor technology, as well as medical technology. Numerous advantagesthat 3D printing offers compared to conventional manufacturing processes give customers more flexibility:
- Necessary Changes to the component can Fast and cost-effective as no new tool is required
- Metal and plastic components that could not previously be produced using conventional ceramic manufacturing processes can now be replaced by 3D printing. The customer benefits from longer service life and higher production stability
- 3D printing enables Complex individual components where several components were previously required. This eliminates the need for assembly and also makes procurement easier
So much for the theory, but what does the whole thing look like in a practical example? The following section looks at a current application in which 3D printing was used to optimize both service life and costs.
Practical example: Non-return valve for fluid atomization in process engineering
In many industries, such as process engineering, the chemical and pharmaceutical industries or the food sector, the Transport, dosing and control of highly abrasive fluids This is an endurance test for the materials used.
Normally, carbide (e.g. tungsten carbide-cobalt, WC-Co) is used in such cases. However, some of the fluids conveyed not only contain abrasive particles, but also corrode the binder phase (cobalt) of the carbide, which leads to component failure within a few hours. Therefore, the Fluids too corrosive for carbide.
Stainless steel 1.4404 as a corrosion-resistant alternative is already state of the art in many areas of process engineering, analytics and medical technology. In the application described here, stainless steel is suitable along straight pipelines, as abrasion is kept within limits. But The wear on valves, baffles and nozzles is too great for stainless steel. An extremely wear-resistant material is therefore required for these components.
This is where ceramics come into play. Aluminum oxide (Al2O3) and zirconium oxide (ZrO2) are very popular for technical applications, but are both suitable here? The corrosion resistance is impressive for both materials, Al2O3 has a higher hardness and therefore better abrasion resistance. In addition, ZrO2 twice as expensive to produce as Al2O3 and there is a risk of long-term hydrothermal ageing in an aqueous environment. Therefore high purity Al2O3 (99.9%) best suited for the application. However, one difficulty remains: as the peripherals are often made of stainless steel, the transition to the standard connections can be problematic, especially if a hermetically sealed connection is required. This can be remedied by combining the best of both worlds.
3D-printed metal-ceramic connection as a solution
Metal-ceramic joints can be produced using a wide variety of methods. Joining by means of active soldering was chosen for the application described, as this process guarantees the highest long-term stability. 3D printing also enables the Free design of the contact point and thus offers the possibility to Fast and cost-effective customization to be carried out. Other manufacturing processes often require tool adaptations, which are significantly more costly and time-consuming.
The actual non-return valve, which comes into direct contact with the aggressive fluids, is made of high-purity aluminum oxide. The ceramic ensures that the High corrosion and abrasion resistance for a Longer service life. The manufacturing process used is 3D printing based on stereolithography. This allows the required tolerances to be maintained and the entire valve displayed in one work step including the internal ball.
The connections to the ceramic are made of 1.4404 stainless steel and were manufactured by our partner Lightway GmbH 3D printed using the SLM process. At the same time, the stainless steel connections create a hermetically sealed connection to the periphery in order to be able to convey the abrasive fluids without leakage. The advantages of both materials were thus optimally utilized.
Combining metal and ceramic is a major technical challenge. The main problem here is the large difference in the coefficient of thermal expansion of aluminum oxide at 8 ppm/K compared to stainless steel 1.4404 at 22 ppm/K. This leads to high stresses at the point of contact between the two materials, both during production and when the component is used at high temperatures, and may cause the entire component to fail. Here too, 3D printing offers a solution. The flexibility of the process enables the contact point to be designed individually. For example, very thin wall thicknesses and a 3D-printed structure at the contact points stresses occurring between metal and ceramic can be dynamically relieved.
The resulting component meets all of the customer's requirements. The connection is hermetically sealed and the ceramic withstands the aggressive environment of the medium significantly longer than previously tested products. Thanks to the longer service life, the number of maintenance cycles was minimized and a more constant production level was achieved.
Outlook
With the experience gained and the consistently positive feedback from the customer, we are also planning to use the metal-ceramic connection technology in other areas. Other interesting applications include use in sputtering systems for vacuum technology and as nozzles in the food industry.
Vacuum technology poses a particular challenge to the quality of the connection, as it must not only be hermetically sealed, but also vacuum-tight. For the nozzles in the second application, ceramics already have a clear advantage over metals and plastics due to their food-safe properties. The use of hard metal is problematic due to the cobalt content of the material. Although nozzles made of high-performance plastic offer cost advantages in the short term, their service life is very short and there is a risk of contamination from microplastics.
On our homepage under hilgenberg-ceramics.com/news/ we regularly present applications that have been optimized through the use of ceramic 3D printing. Our process also offers you the performance and flexibility you need for your individual application.
Do you have any further questions about our article? Or would you like to explore the options of ceramic 3D printing for your own application? You can contact us at any time by email or phone.
