The present and future of 3D metal printing

A similar approach is derived, by mean of using laser source, in selective laser melting (SLM), aka direct metal laser sintering (DMLS) by bonding metal powder particles that, now, undergo complete phase of melting. The idea of implementing SLM in 3D metal printing revolution originates back in 1980s when Japanese researcher Hideo Kodama discovered polymerisation of some photosensitive polymers under UV light. The invention is known as stereo-lithography and fond its use in many areas for more than 25 years. The procedure of printing a metal product is similar to the one implemented for stereo-lithography, and consisted of slicing a 3D model onto layers (cross-sections of the geometrically defined part), and then sinter metal particles by scanning a cross-section of the powder layer with the laser beam. Next, the building bed lowers down by the distance of predefined 3D slice width followed by spreading over with the new powder amount. Thus, a 3D part is build up layer by layer from the fused powder particles while unprocessed powder could be recycled.

Surface integrity parameters

DMLS technique theoretically has no limitations on achieving 3D products with complex geometries because during the building process there is no need to provide support structures (such as in FDM) – the powder itself serve as a support resulting in product designs that cannot be manufactured using conventional methods like machining where material cannot be physically removed. The only drawback in DMLS technique is that it is practically impossible to build a 3D closed hollow sphere since there is no way to remove non-sintered powder from it.

Material density using 3d laser sintering

Theoretically speaking, it should not have any limitations on achieving the final product with properties as an initial raw material. However, the process born on the edge of the new millennia is still yet to be totally understood. The major problems discovered states that oxygen should be avoided during sintering process, powder beds should be preheated to prevent micro-cracking due to thermal stress, and other technical factors. DLMS still undergoes theoretical studies that examine and control a numerous amount of parameters of this technique such as laser power, scanning speed, powder bed temperature, oxygen concentration in a build chamber, and much more. Every step in this exploration is bringing DLMS theory to the perfection. Laser Photonics is constantly researching and investing into perfecting the DLMS theory with their own research facility.

Surface quality of printed part

The quality of the surface (referred also as roughness and surface finish) is directly related to height of the powder layer and a laser beam spot size. The tinier the powder layers, the finer the final product. However, with this course, the buildup time is raised drastically without post-processing. Laser Photonics manufactures an industrial grade CleanTech products devoted to surface treatment and surface preparation. This technology is used in depainting, degreasing, oxides/rust removal, and surface pre/post welding treatment. Recently the application of this technology was broadened by using it for surface smoothening/reshaping of laser sintered products.

Aluminum or titanium powder printed parts

A number of DLMS unit parameters influence the brittleness of final product such as laser power, scanning speed, powder particles size and composition, bed temperature, and so on. All of those parameters are tied up to the main one – the build chamber size, and could be adjusted consequently during the test procedure.

3D Laser sintering applications

Medical applications are early 3D adopters of laser metal printing for medical orthopedics benefit significantly from the ability of 3D Laser Metal Printing to manufacture complex geometries and structures with high grade powders such as titanium. From patient-specific implants to ultimately, volume production of orthopedic implants featuring hybrid structures and textures; 3D laser metal printing has the potential to unlock manufacturing capabilities that combine free-form shapes and intricate lattice structures that improve Osseo integration, leading too much improved patient outcomes and reduced operating time-tables.

Industrial Applications: from tooling inserts featuring conformal cooling channels to lightweight structures for challenging and critical high technology applications, 3D laser metal printing significantly reduces the constraints on designers. This design freedom results in optimised structures and shapes that would otherwise be constrained by conventional processes or the tooling requirements of large volume production. 3D laser metal printing helps to reduce lead times, reduce tooling costs & permits the creation of designs not previously possible.

Large scale use of 3D printing in manufacturing

Today’s DMLS systems have fulfilled the role of fast track prototyping, however, these systems have been confirmed across all market sectors failing to provide the level of parts quality that requires regulatory approval (FDA/FAA) with regards to patient and/or passenger safety prohibiting metal printing companies from moving applications into a production environment. 3D metal AM systems today meet the classical definition of an unstable process based on metal printed parts data that exhibit unit-to-unit variations that do not behave consistently over time or within normal distribution control limits. As a result, these systems are marketed for prototype or proof of concept programs. Metal printed parts are required to achieve MRL10 to meet conditions to move the application into production. The most experienced metal printing companies average MRL4. The main challenges to address in achieving MRL10 relate to process reliability (Unstable Process), inconsistent quality, size limitations, and metal printing speeds.

Fonon Corp. teamed with Laser Photonics Corp. (LPC) in developing next-generation 3D Metal Printing System Patents/IP. LPC has successfully demonstrated a prototype system drawing tremendous interest from industry experts. Combining both FTI/LPC Intellectual Property represents the largest portfolio of technologies placing Fonon in the unique position to manufacture the next-generation of specialised 3D Metal Printing System. Fonon’s next-generation metal printing systems address common industry applications utilising the company’s proprietary IP developed for parts quality and optimised for manufacturing purposes.

LPC’s BTS™ Transformational Technology now opens new doors for space applications onboard space ships or orbiting space stations tooling rocket engine and space craft parts in a deep vacuum environment.
Today, the company focuses on designing and manufacturing of application specific systems for warhead manufacturing, bone structures and knee replacements systems, automotive parts AM systems, and aerospace turbines and components manufacturing equipment.

Source: Laser Photonics