Applications of metal L-PBF

Applications of L-PBF

L-PBF with applications across all industries

Laser Powder Bed Fusion (L-PBF) is the most industrialized metal AM technology today. After early adopters within the medical and aerospace industry have proven the suitability of L-PBF for end use parts, companies across all industries have identified further cases in recent years.

L-PBF can be used to produce complex geometries ranging from several millimetres to dimensions close to 1m. Recent advancements in productivity and the increasing automation of subsequent process steps make L-PBF more and more suitable for applications in higher volumes. The technology therefore has a wide range of applications, including prototypes, end-use components, toolings and spare parts. 

Image Source: EOS GmbH

Catalytic reactors

User

Addcat

Industry

Industrial

Material

Stainless Steel

Technology

Laser Powder Bed Fusion

Classification

Non-qualified end part

Air purification component. 3D printing gives the free form design possibilities to fully optimize the structure of a catalytic reactor, going beyond designs made with traditional processes. This enables AddCat to improve the catalytic process making the air purification more efficient and reliable in a smaller reactor volume. Courtesy of AddCat

Anti-scatter grid

User

Dunlee

Industry

Medical

Material

Tungsten

Technology

Laser Powder Bed Fusion

Classification

Qualified end part

The anti-scatter grid (ASG), made out of pure tungsten, is placed on top of CT detectors to enhance image quality by rejecting scattered radiation. Through additive manufacturing, it is possible to 3D print 100 micron thick walls at a positional accuracy of 25 microns. Ability to print highly accurate and thin walls (100 microns). Courtesy of Dunlee

ARNO Cutting Tool

User

Rosswag GmbH

Industry

Tooling & Molding

Material

Tool Steel

Technology

Laser Powder Bed Fusion

Classification

Tools and fixtures

Cutting tool innovation by ARNO and Rosswag with patented coolant supply design manufactured in serial production. The additive manufactured grooving tool delivers coolant directly to the cutting zone of the insert and underneath the tool flank for highly efficient parting off, grooving and groove turning. This leads to financial and technical benefits due to an increased tool life of the insert and a higher process security.   Courtesy of Rosswag GmbH.

Hydraulic valve block

Old vs. new design

User

Airbus

Industry

Aviation

Material

Stainless Steel

Technology

Laser Powder Bed Fusion

Classification

Qualified end part

The objective was to replace a conventionally manufactured high-pressure hydraulic valve block with an additively manufactured one. The component is produced by LIEBHERR AEROSPACE and used on an AIRBUS A380.

The primary flight control component moves the spoiler of an aircraft to the desired position during take-off and landing and must thus meet highest quality standards.

The original component is machined from a forged block with several drillings and assembly operations. This leads to limited design freedom and long lead times. 

Autoclave for High Pressure Applications

User

BASF SE

Industry

Industrial

Material

Stainless Steel

Technology

Laser Powder Bed Fusion

Classification

Qualified end part

The autoclave with integrated tempering channels is certified according to the European Pressure Equipment Directive (2014/68/EU) Category III. It has an operating pressure of 225 bar. The autoclave features a more than two meter long interior channel for tempering fluid which winds around the container wall. The AM design enables faster temperature cycles, better regulation of an even temperature distribution as well as optimized tempering of the component. The component is produced with L-PBF from stainless steel alloy. Courtesy of BASF SE.

Energy feedthrough

User

Festo AG & Co. KG

Industry

Industrial

Material

Aluminium

Technology

Laser Powder Bed Fusion

Classification

Non-qualified end part

The part transmits and distributes compressed air. Advantage by Additive Manufacturing through economic substitution of costly extrusion press part. Images courtesy of Festo AG & Co. KG

Sinter-based AM technologies and process chain

Sinter-based AM - a technology overview

Many different printing technologies - one sintering process

The sinter-based AM (SBAM) technologies have, as the name suggests, the sintering process in common. In this process, the printed green part is consolidated into a dense part and receives its final properties. The green part can be printed in advance using different technologies.They all have in common that metal powder is bound to the desired shape by a binder. The best-known printing technologies include Binder Jetting and Filament Material Extrusion.

In this section, you learn everything about the sinter-based AM  process chain and get an overview of the different printing technologies.

Goal and structure of this course

This course is aimed at engineers, designers and other professionals that are working closely with sinter-based AM technologies. The goal is to cover the most important aspects that will enable engineers and designers to fully grasp the capabilities and technical limitations of the printing technologies and the sintering process to succeed in technology selection and part design. Besides going through the course from the beginning until the end, this course can also act as a constant source of knowledge while working on AM projects. 

The course is structured into the following sections.

This section will start with an overview of the sinter-based AM process chain and its printing technologies, followed by a technology deep dive into the most important aspects of the BJT technology, followed by a closer look at the debinding and sintering step also including sintering simulation .

The second section will provide an overview of the different materials that are available as well as part characteristics that can be achieved with the BJT process and typical methods for quality assurance. Finally, several common defects in the BJT process are presented. 

The last section will act as a guideline for designers. Besides generally describing the process when designing for Additive Manufacturing, actionable restrictions and guidelines for the BJT process are provided. The final section will present several design examples from different industries. 

What you will find in this section

Sinter-based AM process chain

From digital model to finished part

Data preparation

Simulation to compensate the deformation during the sintering step, nesting of parts and definition of printing parameters

Printing

Through various printing processes, different feedstocks such as metal powders, filaments, pellets or dispersions are processed into green parts

Unpacking

Unpacking of fragile green parts needs to be done carefully and is typically a manual process.

Debinding

Debinding describes the process of removing the binder which results in a brown part

Sintering

To reach the structural integrity of a metal part, a sinter process is required. The powder particles fuse together to a coherent, solid structure via a mass transport that occurs at the atomic scale driven via diffusional forces.

The brown part shrinks ~13-21 % in each direction.

The process chain of sinter-based technologies differs from other AM Technologies. Especially the post-printing processes (debinding and sintering) are crucial to achieve the intended mechanical properties.

Technology principle

How does Binder Jetting work?

Binder Jetting is a powder based Additive Manufacturing technology in which a liquid polymer binder is selectively deposited onto the powder bed binding the metal particles and forming a green body.

The metal powder is applied to a build platform in a typical layer thickness of 40 µm to 100 µm. Subsequently a modified 2D print head apply a binder selectively onto the powder bed. Depending on machine technology a hardening or curing process of the binder is performed in parallel for each layer and/or at the end of the whole build. During the in-situ curing process a heat source is used to solidify the binder and form a solid polymer – metal powder composite.

Working Principle of Binder Jetting

Afterwards the build platform moves downward by the amount of one layer thickness and a new layer of powder is applied. Again, the liquid binder is deposited and hardened in the required regions of the next layer to form the green body. This process is repeated until the complete part is printed. After the complete printing process is finished the parts have to be removed from the “powder cake” meaning the surrounding loose but densified powder. To improve the removal of the excess powder from the green body often brushes or a blasting gun with air pressure are used.

To create a dense metal part the 3D printed green body has to be post-processed in a debinding and sintering process. Similar to the metal injection molding process BJT parts are placed in a high temperature furnace, where the binder is burnt out and the remaining metal particles are sintered together. The sintering results in densification of the 3D printed green body to a metal part with high densities of 97 % to 99,5%, dependent of the material.

Printing Technologies

Metal Binder Jetting

Binder Jetting is a powder based Additive Manufacturing technology in which a liquid polymer binder is selectively deposited onto the powder bed binding the metal particles and forming a green body.

The metal powder is applied to a build platform in a typical layer thickness of 40 µm to 100 µm. Subsequently a modified 2D print head apply a binder selectively onto the powder bed. Depending on machine technology a hardening or curing process of the binder is performed in parallel for each layer and/or at the end of the whole build. During the in-situ curing process a heat source is used to solidify the binder and form a solid polymer – metal powder composite.

Working Principle of Binder Jetting

Material Extrusion

Binder Jetting is a powder based Additive Manufacturing technology in which a liquid polymer binder is selectively deposited onto the powder bed binding the metal particles and forming a green body.

The metal powder is applied to a build platform in a typical layer thickness of 40 µm to 100 µm. Subsequently a modified 2D print head apply a binder selectively onto the powder bed. Depending on machine technology a hardening or curing process of the binder is performed in parallel for each layer and/or at the end of the whole build. During the in-situ curing process a heat source is used to solidify the binder and form a solid polymer – metal powder composite.

Working Principle of Binder Jetting

Mold Slurry Deposition

Binder Jetting is a powder based Additive Manufacturing technology in which a liquid polymer binder is selectively deposited onto the powder bed binding the metal particles and forming a green body.

The metal powder is applied to a build platform in a typical layer thickness of 40 µm to 100 µm. Subsequently a modified 2D print head apply a binder selectively onto the powder bed. Depending on machine technology a hardening or curing process of the binder is performed in parallel for each layer and/or at the end of the whole build. During the in-situ curing process a heat source is used to solidify the binder and form a solid polymer – metal powder composite.

Working Principle of Binder Jetting

Metal Selective Laser Sintering

Binder Jetting is a powder based Additive Manufacturing technology in which a liquid polymer binder is selectively deposited onto the powder bed binding the metal particles and forming a green body.

The metal powder is applied to a build platform in a typical layer thickness of 40 µm to 100 µm. Subsequently a modified 2D print head apply a binder selectively onto the powder bed. Depending on machine technology a hardening or curing process of the binder is performed in parallel for each layer and/or at the end of the whole build. During the in-situ curing process a heat source is used to solidify the binder and form a solid polymer – metal powder composite.

Working Principle of Binder Jetting