Additive manufacturing: key questions and answers

What are the benefits of additive manufacturing?

In industry, especially in sectors using pumps and valves, I can see a number of benefits.

What are the disadvantages of additive manufacturing?

Naturally, additive manufacturing processes have also got some disadvantages and provide some challenges.

All in all, additive manufacturing provides an alternative to methods such as injection moulding, milling or turning, all of which have got their own specific advantages and disadvantages. In product development and production it is important to weigh up what method is best suited for a specific order.

What are the different additive manufacturing procedures?

Additive manufacturing can be carried out using different methods. Currently, our focus is on metal powder bed fusion with a laser beam (PBF-LB/M). This technology, that used to be called selective laser melting (SLM), uses a laser to melt the powder. With this method we can process almost all weldable materials. However, it is not suitable for materials with a high carbon content or special alloys. In such cases, an electron beam can be used as an energy source instead.  

Another method is polymer powder bed fusion with a laser beam (PBF-LB/P), which used to be called selective laser sintering (SLS). Here, the powder is initially heated up and then sintered with a laser. With this procedure we can produce high-quality plastic components, for example. Almost every material can be matched with a suitable additive procedure. Special materials that cannot be processed with one of the methods can often be processed successfully with a different method. This allows us to work with a large range of metals, including diverse stainless steel and nickel base alloys.

Here are some further additive manufacturing procedures:

What components is additive manufacturing suitable for?

Additive manufacturing can be particularly recommended for components that are very complex or have got special material properties. Examples are components with complex geometries, such as gyroid structures. These are organic, three-dimensional patterns that provide components with an excellent stability to weight ratio. Such structures cannot be created using traditional procedures such as casting, turning or milling. An example of a KSB product that simply would not exist without additive manufacturing is the recently introduced MagnoProtect containment shroud for KSB mag-drive pumps.

The material quality does not need to be compromised: It exceeds that of cast components as no shrinkage cavities or stresses and strains can occur. It is roughly comparable to forged material.

For critical, system-relevant components the time benefit of additive manufacturing comes into play. We can manufacture parts of any type very quickly. If a pump fails in a critical process of a chemical plant, for example, the entire system will be down, leading to five- to six-digit losses per hour. The faster we can replace the defective component, the lower the damage.

In the end, additive manufacturing systems are worthwhile when low component quantities are needed. Producing an injection moulding tool can easily cost 10,000 euros or more. For a market launch, for example, aiming initially to test the product, the costs usually far exceed the revenue generated. Here it makes sense to initially make individual parts by additive manufacturing before they will later be series-produced. Any changes resulting from the initial application experiences can thus be made in a significantly more cost-efficient manner.

A similar scenario is that of spare parts procurement, especially for older or less common systems. Traditionally, producing rare spare parts could take weeks to months, and a huge warehouse of spare parts would have to be stocked. Instead, we are establishing a digital warehouse stocking 3D data sets. If and when a spare part is required, we access its design data and produce it in a very short time: "Parts on Demand" is the key.

At KSB we not only offer our additive manufacturing competencies and technologies to KSB customers but also to external customers, which means we also manufacture non-KSB-specific components.

Additive manufacturing and digital warehouse – could you explain this concept to us in more detail, please?

In principle, a digital warehouse is a virtual space in which digital models of spare parts are stored. They can then be produced directly by additive manufacturing in the required quantity and quality. Instead of a physical stock, we have got a digital stock than can be printed on demand. At present, we are using this technology internally for prototypes, patterns and spare parts. In the long term, we would like to establish an online appearance for our customers, where they can order parts in a shop or manage their own digital spare parts warehouse.

Among the biggest benefits for us and our customers are flexibility and speed. We can produce spare parts exactly when and where they are needed. This drastically reduces delivery times and enables us to offer tailored solutions. We also considerably reduce storage costs as no large physical stock has to be kept. In the long term, this will play an increasingly important role, and we will be able to replace traditional spare parts supply in many areas.

An impressive example is the above-mentioned project for a nuclear power station, where we manufactured an urgently required impeller within a mere 48 hours. With traditional methods this would have taken several months to produce. Our digital warehouse allowed us to access the model and start production immediately.

How can additive manufacturing contribute to more sustainability?

Additive manufacturing procedures use less material than classic methods. In extreme cases of metal-cutting, for example, 90 percent of the raw material may end up as metal chips. Even though they can be reused, this requires additional energy. With the exception of support structures and allowances for machining, additive manufacturing only uses the material that is actually required. Studies have shown that additive manufacturing is less sustainable for series production than casting methods, for example, as it uses more energy.

However, looking at a product’s entire life cycle is important when assessing its true sustainability. In their application, components made by additive manufacturing show some clear benefits, such as in the production of spare parts for systems that have been running for several decades. Extending the systems’ service life is certainly sustainable. Stockkeeping plays a role in the sustainability balance too. A digital warehouse reduces the need for physical warehouses and the corresponding land consumption. In addition, CO₂ emissions by transport are reduced when we manufacture parts near their place of use instead of transporting them over long distances.

Most of all, it is the freedom of design that contributes to the sustainability of additive manufacturing. Additive manufacturing enables complex designs, saving weight and energy. An additively manufactured heat exchanger, whose efficient structure saves 15 percent of fuel, offsets its CO₂ footprint within a few operating hours. Additive manufacturing allowed us to produce the MagnoProtect containment shroud, for example. With its complex channel structures, in which a vacuum is present, it protects the operators from leakage of corrosive or toxic liquids, for example. At the same time, it enhances the overall efficiency of the pump, which saves energy.  Even though additive manufacturing may be more energy-intensive, the initial energy needed can be more than offset by the power reduction during operation, thus contributing to more sustainability.

To conclude: How do you envisage the future of additive manufacturing?

I think that additive manufacturing will continue to gain in importance. The technology will become faster, more cost-efficient and more versatile. The costs are sinking continuously. When we first started, stainless steel powder costed 100 euros per kilogramme; now it is only about 30 euros. And the machinery is getting more efficient, too. Nevertheless, traditional methods will always remain more economical for specific applications. It is unlikely for additive manufacturing to completely replace traditional methods. Every technology has got its own strengths. Selecting the right technology for each application is what counts. The effect of additive manufacturing systems on warehousing could be almost revolutionary in the future. It enables the establishment of digital warehousing and thus makes spare parts procurement more efficient and flexible.