The laser metal fusion process starts with the virtual 3D model of the component as a CAD drawing. During data preparation, the workpiece is divided into many individual layers ("slices") and, if required, a support structure is attached. The workpiece is finally built up layer-by-layer in the process chamber under shielding gas on a substrate plate. The oxygen level here is 0.1 percent. In the chamber, the supply cylinder, build cylinder, and overflow cylinder are next to one another in one axis. The recoater shifts the powder from the supply cylinder to the build cylinder. The laser then melts the first layer of powder according to the part contour. In the next step, the build cylinder is lowered and the excess powder lands in the overflow cylinder. This process is repeated until the component has been generated completely. In order to increase productivity, TRUMPF uses multiple lasers that work simultaneously in its systems. This is referred to as a multilaser principle. Metal powder is finally removed from the finished part in an unpacking station. The component is then separated from the plate, the support structures (if present) are removed, and, if required, the workpiece is reworked.
Laser metal fusion – benefits, working principles, and applications of the additive technology
Laser metal fusion is an additive manufacturing method where a workpiece is built up gradually in a powder bed. To do so, a laser melts down the metal powder in material layers precisely at the points specified by the component's CAD construction data. The process is therefore often known as metal 3D printing/3D printing; the term laser sintering is also common in the industry. The process is optimally suited for series production of geometrically complex parts with delicate internal channels and cavities that cannot be produced using conventional processes such as turning or grinding or can only be produced less effectively. Components which exhibit high stability as well as a low weight are created using industrial 3D printing – this is particularly beneficial for lightweight design or customized implants and prostheses. Furthermore, laser metal fusion is a sustainable production method, as, compared to ablative processes, no chips (and therefore little excess material) is created. With almost two decades of experience in additive technology, TRUMPF provides complete packages for powder bed processes that are mature for industry – consisting of machines, services, and digitalization from a single source. From part identification to the finished product and beyond – we cover the entire process chain for you.
Users can directly create functional components – e.g. with integrated cooling channels – from 3D CAD models using LMF.
Using LMF, components with conformal cooling can be produced. They dissipate the heat that is produced during the production process right where it is created.
In additive manufacturing, construction using lattice structures enables significantly quicker production of components.
During 3D printing, the construction and the design determines the production of the component – unlike in conventional production processes.
Practically no setup time is required in the case of 3D printing. This means that you can always utilize your machines optimally and increase the efficiency of your production.
The Industrial Part and Powder Management from TRUMPF increases the productivity of your production.
A closed powder circuit ensures a clean and safe production environment.
The laser metal fusion process explained in brief
Applications and areas of use – as diverse as the technology itself
Laser metal fusion meets the high quality and safety requirements when it comes to the production of medical devices and implants. The shown personalized cranial implant made from titanium was produced in 8 hours and 45 minutes and with almost 5,000 layers, for example.
In aerospace engineering, lightweight design while maintaining a good flow of forces within the workpiece is of utmost importance. This topology-optimized design can be produced easily using powder bed processes – as with the mounting bracket for airplane doors shown. It was built up within 8 hours and with almost 2,700 layers.
The hydraulic block shown is used for coupling between the control valve and the hydraulic cylinder. If it is produced with the laser metal fusion method, its total volume can be reduced by 80% and the pressure loss can be reduced by 93% – without any loss of function. The construction process was carried out without any support structures and was completed in eleven hours.
Five single parts would conventionally be required to produce this runner. In the case of laser metal fusion, you produce the finished component directly. Close-contour, complex tempering channels can be generated easily using LMF. Moreover, customers benefit from cycle time reduction and thermally stable production processes with a minimal reject rate. The runner in the image was produced within 70 hours.
In the automotive industry, complex, functional prototypes can be constructed quickly and without any tools using laser metal fusion. Additive manufacturing of the axle support shown took five hours.
The dental industry also benefits from the many advantages of additive manufacturing. Any desired complex indications can be constructed highly precisely and in record time layer-by-layer with bio-compatible material. The dental pad with dental crowns shown was produced within six hours with around 1,200 layers.
Which products are suitable for laser metal fusion?
Laser metal fusion (LMF)
Laser metal fusion is often called metal 3D printing, powder bed fusion, or selective laser melting. The laser builds up the workpiece layer by layer from a powder bed. A CAD model provides the plan. Tools are not required. The powder is applied to a build platform. The laser beam melts the powder very precisely according to CAD data and connects defined points with the layer below. The laser repeats this process until the metal part is finished. The workpiece has the characteristics of the material used in powder form. A large number of metal materials can be used in powder form, e.g. steel, aluminum, or titanium.
Advantages of laser metal fusion
As a supplement to conventional production methods, the LMF method offers a number of advantages. There are virtually no limits on the design freedom, which enables complex forms and custom components to be produced quickly, cost-effectively, and with flexibility. When conventional production methods reach their limits, LMF can provide the answer. It enables cost-effective production, even for small lot sizes.
Areas of application
The components produced using this method meet stringent material requirements for demanding applications. As a result of the components' stability and low weight, the method is ideal for lightweight designs and bionic structures, such as those found in the aviation and aerospace, automotive, and medical technology sectors.