3D printing in the metal industry – processes, opportunities, challenges and areas of application for additive manufacturing processes

The use of additive manufacturing methods in industry has increased significantly over the past ten years. This shows the increased willingness of many companies to invest in this technology. This applies not only to 3D printing in general, but in particular to the additive manufacturing of metals. 

Important 3D printing processes for metals

The most widely used additive manufacturing methods today are:

  • Selective laser melting (SLM)
  • Electron beam melting (EBM)
  • Laser metal deposition (LMD)
  • Wire arc/plasma arc energy deposition
  • Wire feed electron deposition

At CERATIZIT, of the various printing processes, we rely on selective laser melting (SLM) as it can be used to produce components with a high tensile strength and excellent material density. The SLM process is particularly suitable for the production of tool base bodies in small to medium batch sizes.

Benefits and areas of application for additive manufacturing

The main advantages of additive manufacturing of metals are evident: The process enables a high degree of flexibility and maximum design freedom – not only in prototype design, but increasingly also in series production.
Additive metal printing can achieve things that aren’t possible with conventional subtractive or casting technologies. The process enables us to combine production steps and thus to produce complex tools for the manufacturing process with higher added value for our customers, as well as to create the tricky components that no one else dares attempt. 

When do we use 3D printing?

Before we decide to manufacture using 3D printing, we first take a very close look at the idea for a component or assembly: “Using a checklist, we perform a critical point-by-point examination of whether additive manufacturing clearly adds value. If this is the case, we will continue pursuing the idea,” says Karl-Heinz Edelmann, explaining the approach.

The next step is the additive design. We believe in fully exploiting the design freedom of 3D printing to achieve the highest possible added value. If, for example, the design is largely self-supporting in the printing direction, hardly any supports are required. This, in turn, saves material and processing time and reduces the reworking of the surfaces after printing.

Which metals are suitable for 3D printing?

Aluminium and steel are the most commonly used metals in 3D printing, with tool steels being a key group. Materials such as cobalt-chrome, Inconel and titanium are also used.

We also often use maraging tool steel to produce tool base bodies for cutting tools. It stands out thanks to its high tensile strength and toughness. It is also easy to carry out a heat treatment with low distortion. Theoretically, all materials used for 3D printers can be recycled. With the powder-bed-based process, the used powder can generally be mixed with new powder and fed back into additive manufacturing. We achieve this without any significant loss of quality.

This is how our PCD tools are produced using a 3D printer:

Other established areas of application of additive manufacturing in the industry

Nowadays, additive processes can be carried out with a wide range of materials. The term “3D plastic” limits the consideration of this technology solely to the polymer and resin-based 3D printing processes. Owing to the low cost of materials and printers, 3D printing of plastics is a popular entry-level process in additive manufacturing, especially in the maker scene.

With the same dynamism as this scene, we also regularly develop and create new products. Production aids and devices form a key field of application. Our expert Karl-Heinz Edelmann explains why plastics are used here in particular: “It’s always important to consider whether components made of steel are required in terms of tensile strength. The key principle is: as strong as necessary! Production aids made of plastic have real benefits: The risk of injury when handling them is often lower. The lower weight compared to steel is also an advantage when it comes to human handling.”
Another important aspect to consider is that devices made of plastic prevent damage when they come into contact with hard materials such as the cutting edges of cutting tools.
A device which is constructed entirely via 3D printing can be produced again in batch sizes of 1 if required. Production and storage costs can also be reduced owing to short delivery times, low manufacturing costs and fast response times when changes are made to models.

Areas of application for plastic additive manufacturing

  • Prototype construction
  • Production of aids and tools
  • Components with complex geometries
  • Lightweight components
  • Customised products
  • Additive manufacturing of small-scale series
  • Production of spare parts for repairs
  • Components that require a large amount of chip-forming machining
  • Components with complex internal contours such as coolant holes

We are now able to produce cutting tools with measurable added value owing to additive manufacturing. More specifically:

  • Higher chip removal rate → more parts output
  • Vibration-free milling of thin-walled components → longer service life
  • Reduction of burr formation on workpiece edges when milling → less reworking
  • Minimisation of residual chips in the component
  • Lightweight tools → large tool diameters with low weight 
Minimised burr formation and perfect surface quality when milling with 3D-printed PCD milling cutters

When is 3D metal printing more beneficial than conventional methods?

Additive manufacturing provides a cost advantage mainly where normal manufacturing is particularly complex, for example if a large amount of material has to be machined. In particular, due to the aforementioned constructive design freedom, functional aspects can also be repeatedly adapted in the development process if necessary. For our customers, this means significant added value in terms of costs and time savings.
We machine other elements such as the shank or tool separation point and later join them together with additively manufactured 3D prints as one component. This creates a hybrid part at an attractive price.

Additive manufacturing allows for greater design freedom

3D printing opens up new technical possibilities for us, through which we can overcome the existing limits of conventional manufacturing processes – for example, with the printing of chip and coolant holes, tools with a higher number of cutting edges and more degrees of freedom in constructive design. 

  • Creation of individual parts → from batch sizes of 1
  • Shapes can be redesigned and optimised → especially useful for complex shapes. It is also possible to change aspects such as weight or size.
  • Shortened manufacturing process → time-consuming production steps such as CNC machining are reduced to a minimum. This is particularly advantageous when producing prototypes, as it speeds up testing and the associated design optimisation.
  • The production process is sustainable as there are fewer waste products.
  • Shorter development loops for new products → lower follow-up reworking costs compared to conventional methods, as only functional surfaces are reworked.
  • Metal parts made using additive manufacturing can also be economical substitutes for high-performance materials.

“Where conventional tool systems reach their physical limits, 3D printing offers us new opportunities to provide our customers with a custom solution for their specific machining situation,” says our expert Patrick Schreiber gladly. Thanks to the high level of freedom in the process, aspects such as the coolant holes, number of cutting edges, stability and weight of a tool can be adapted to the relevant machining situation.

→ We have wide fields of application, for example in e-mobility, where the trend is clearly in the direction of smaller quantities and greater component variation.

We can even create trickier components

Tricky components like this complex wheel carrier can be achieved thanks to additive manufacturing.

The components are often very thin-walled and require extreme accuracy. With conventional solutions, this often leads to vibrations during the machining process. This is where we intervene: “With our modular tool systems, fast delivery times are possible with the best tool quality,” explains our expert Patrick Schreiber. We work according to a modular principle. The basic framework of the tool is already defined, so we need only expand it with the customer-specific 3D-printed attachment. We have thereby significantly reduced our delivery times – moreover, tool solutions are now possible that set new standards in strength and weight optimisation.

Future challenges of additive manufacturing

3D printing with metal is still relatively expensive, which is why solutions are usually hybrids. We use additive manufacturing only where there is actually added value. As always, our customers can choose between a subtractive method, hybrid method and 3D-printing method.

  • Improvement of process repeatability
  • Reliability of the printing process
    → Both can be solved through proper additive design. Design must be rethought. (Key word: support structures)
    → Positive example from Green Team

 

Additive manufacturing: Ideas cubed

Our experts are highly sought-after when it comes to individual tool solutions for series production. Here, they explain why hybrid tools play such an important role.