Research and Development in Materials and Processes of Superalloy Fabricated by Laser Additive Manufacturing

Titanium (Ti) alloys are widely used in high-tech fields like aerospace and biomedical engineering. Laser additive manufacturing (LAM), as an innovative technology, is the key driver for the development of Ti alloys. Despite the significant advancements in LAM of Ti alloys, there remain challenges that need further research and development efforts. To recap the potential of LAM high-performance Ti alloy, this article systematically reviews LAM Ti alloys with up-to-date information on process, materials, and properties. Several feasible solutions to advance LAM Ti alloys are reviewed, including intelligent process parameters optimization, LAM process innovation with auxiliary fields and novel Ti alloys customization for LAM. The auxiliary energy fields (e.g. thermal, acoustic, mechanical deformation and magnetic fields) can affect the melt pool dynamics and solidification behaviour during LAM of Ti alloys, altering microstructures and mechanical performances. Different kinds of novel Ti alloys customized for LAM, like peritectic α-Ti, eutectoid (α + β)-Ti, hybrid (α + β)-Ti, isomorphous β-Ti and eutectic β-Ti alloys are reviewed in detail. Furthermore, machine learning in accelerating the LAM process optimization and new materials development is also outlooked. This review summarizes the material properties and performance envelops and benchmarks the research achievements in LAM of Ti alloys. In addition, the perspectives and further trends in LAM of Ti alloys are also highlighted.

PurposeThis study aims to discuss the state-of-the-art digital factory (DF) development combining digital twins (DTs), sensing devices, laser additive manufacturing (LAM) and subtractive manufacturing (SM) processes. The current shortcomings and outlook of the DF also have been highlighted. A DF is a state-of-the-art manufacturing facility that uses innovative technologies, including automation, artificial intelligence (AI), the Internet of Things, additive manufacturing (AM), SM, hybrid manufacturing (HM), sensors for real-time feedback and control, and a DT, to streamline and improve manufacturing operations.Design/methodology/approachThis study presents a novel perspective on DF development using laser-based AM, SM, sensors and DTs. Recent developments in laser-based AM, SM, sensors and DTs have been compiled. This study has been developed using systematic reviews and meta-analyses (PRISMA) guidelines, discussing literature on the DTs for laser-based AM, particularly laser powder bed fusion and direct energy deposition, in-situ monitoring and control equipment, SM and HM. The principal goal of this study is to highlight the aspects of DF and its development using existing techniques.FindingsA comprehensive literature review finds a substantial lack of complete techniques that incorporate cyber-physical systems, advanced data analytics, AI, standardized interoperability, human–machine cooperation and scalable adaptability. The suggested DF effectively fills this void by integrating cyber-physical system components, including DT, AM, SM and sensors into the manufacturing process. Using sophisticated data analytics and AI algorithms, the DF facilitates real-time data analysis, predictive maintenance, quality control and optimal resource allocation. In addition, the suggested DF ensures interoperability between diverse devices and systems by emphasizing standardized communication protocols and interfaces. The modular and adaptable architecture of the DF enables scalability and adaptation, allowing for rapid reaction to market conditions.Originality/valueBased on the need of DF, this review presents a comprehensive approach to DF development using DTs, sensing devices, LAM and SM processes and provides current progress in this domain.

Progress and perspectives in laser additive manufacturing of key aeroengine materials

Laser Additive Manufacturing (LAM) titanium powder consolidation has been practiced for a number of years. The LAM technology holds great promise for repair, direct fabrication and modification of titanium Alloy components. This technology also provides for surface modification through alloying and physical texturing. The LAM technology has been applied to the development of a number of aerospace applications through its ability to add almost any powder material to a surface of an existing sub-structure. However, this technology as been limited by its inability to function in true 3-D environments. The limitations have been the result of the inability to easily translate from solid models and program in parameter changes at selected points. This paper describes a new method that allows true three-dimensional fabrication to those applications where a high resolution and tolerances are important (e.g., knife edges, seal edges, optics fixtures). The new system, MicroLam (m-Lam), an adaptation of the flexible robotic environment (FRE) to LAM, is being developed to fabricate bio-medical devices under a contract (#W81XWH-08-1-0315) through the US Army Medical Command. The m-Lam employs a six axis coordinated motion system with a higher resolution (∼100 microns) than previously possible for other LAM systems. The general areas where this and the current LAM technologies will be directed includes but is not limited to: repair of complex structures: fabrication of additive shapes on existing structures; seal edges; leading edges; wear resistant surfaces containing a variety of conventional carbides, silicides, borides and novel nano-particle reinforcements; build up of functional material on wrought and cast structures; and functionally gradient transition layers.Laser Additive Manufacturing (LAM) titanium powder consolidation has been practiced for a number of years. The LAM technology holds great promise for repair, direct fabrication and modification of titanium Alloy components. This technology also provides for surface modification through alloying and physical texturing. The LAM technology has been applied to the development of a number of aerospace applications through its ability to add almost any powder material to a surface of an existing sub-structure. However, this technology as been limited by its inability to function in true 3-D environments. The limitations have been the result of the inability to easily translate from solid models and program in parameter changes at selected points. This paper describes a new method that allows true three-dimensional fabrication to those applications where a high resolution and tolerances are important (e.g., knife edges, seal edges, optics fixtures). The new system, MicroLam (m-Lam), an adaptation of the flexible...

A cutting-edge manufacturing technology that uses powder or wire as the feeding material and a high-energy heating source is known as metal additive manufacturing (AM). High-performance components for automotive, aerospace, medical, and energy applications are designed and produced using additive manufacturing (AM). In this overview, only laser additive manufacturing (LAM) procedures such as powder bed fusion (PBF) and directed energy deposition are discussed (DED). LAM provides an alternate path for fabricating current designs and permits the creation of new designs with complexity that is not possible with conventional methods. One of the most promising forms of additive manufacturing is laser additive manufacturing, which may produce things at low cost while keeping high value and yield (LAM). Specifically, when it comes to directed energy deposition (DED) or powder bed fusion (PBF), which involve various types of wire-fed, powder fed, and powder-bed assembly, it examines the key metallurgical phenomena that occur during LAM as well as the distinctions between different LAM technological pathways. This study offers a thorough overview of the classification of LAM systems, applications of LAM processes, key processing factors, frequent flaws, mechanical characteristics of manufactured parts, numerous machine-related parameters, and optimization of deposition conditions.

Beam shaping technology and its application in metal laser additive manufacturing: A review

Laser additive manufacturing (LAM) is a layer wise fabrication technology which enables the production of complex shaped, individually designed parts with mechanical properties comparable to conventionally manufactured parts. However, the part manufacturing is relatively slow and via this whole production feasibility is not yet totally studied for real series production, as findings from literature shows. It is obvious that many of those studies are carried out in companies “behind locked doors” and because of this whole era of research is suffering of this lack of information.Even though the throughput time from idea to real metal product is short, the throughput time of the actual LAM phase could still be improved to gain more feasible fabrication method. Due to this, it is necessary to increase the build rate in order to improve the process efficiency and also improve whole production feasibility of LAM. It was observed that there are only few public studies about process efficiency of laser additive manufacturing of stainless steel. According to literature, it is possible to improve process efficiency with use of higher laser power and thicker layer. The process efficiency improvement is possible if the effect of process parameter changes in manufactured pieces is known.The manufacturing strategy of track by track and layer by layer involves a lot of different independent and dependent thermal cycles all having an influence on the part and material properties and this way to end result of process.Experimental tests of this study were made with two different machines: with a modified research machine representing EOS EOSINT M-series and with an EOS EOSINT M280. Material used was stainless steel 17-4 PH.Since the quality of manufactured parts depend strongly on each single laser-melted track and each single layer, this study concentrates to investigating the effects of the processing parameters such as scanning speed and laser power on single-track formation.It was concluded that heat input has an important effect on the penetration depth and possibility to melt thicker powder layers. These factors were noticed to be crucial for improving process efficiency. It was concluded in single track tests that some of the tracks have very deep and narrow penetrations into the bulk material. It was also observed that there is possibility to form keyhole in each exposed track with the tested parameters. It was concluded that laser interaction time has effect on the depth of the penetration and keyhole formation, since the penetration depth is increasing while the laser interaction time increases.Laser additive manufacturing (LAM) is a layer wise fabrication technology which enables the production of complex shaped, individually designed parts with mechanical properties comparable to conventionally manufactured parts. However, the part manufacturing is relatively slow and via this whole production feasibility is not yet totally studied for real series production, as findings from literature shows. It is obvious that many of those studies are carried out in companies “behind locked doors” and because of this whole era of research is suffering of this lack of information.Even though the throughput time from idea to real metal product is short, the throughput time of the actual LAM phase could still be improved to gain more feasible fabrication method. Due to this, it is necessary to increase the build rate in order to improve the process efficiency and also improve whole production feasibility of LAM. It was observed that there are only few public studies about process efficiency of laser additive m...

In the recent years, Laser Additive Manufacturing (LAM) has become a rather well-established manufacturing process to produce metallic parts. However, the very special consolidation conditions during AM with multiple heating and cooling at high rates may lead to complex out-of-equilibrium microstructures, pronounced element segregation and crack formation in the bulk alloy. However, there have been only a limited number of reliably processable alloys used in LAM so far, and the processing parameters are usually obtained in a trial-and-error approach. In order to exploit the advantages of LAM, novel alloys and composites adapted to the special processing conditions during LAM need to be developed. This requires a deep understanding of the materials consolidation process during LAM, which is currently still lacking. This talk will give an overview of the challenges and opportunities in LAM from a materials scientist’s perspective. Results of the LAM related research at Empa with a special emphasize on the optimization of Ti, Al and Cu based alloys will be presented.

Today, Laser Additive Manufacturing (LAM) is typically performed using a single beam with power up to multiple-kilowatts. The associated high heat input and limited process control hampers tight manufacturing tolerances and the applicable material spectrum. This paper highlights the development of Multi-beam LAM technology to address the shortfalls of today’s technology and to broaden the applicability to many industries. Multi-beam LAM deploys several low power beams, each precisely controllable with a minimum heat input thus providing the capability to tailor the applied energy to the specific needs of the application. The single beams either work in parallel to scale productivity without sacrificing precision or in close proximity creating desired heat profiles. This new approach is scalable in productivity through multiplication and is expected to allow deposition of difficult to coat materials through tailored heat profiles. Advances are expected in near net shape manufacturing of complex structures with fine features and high dimensional accuracy.A compact prototype processing head for Multi-beam LAM was designed and built to investigate the capability of the new technology. The head incorporates latest high-brightness diode laser technology and a compact powder nozzle design. Two laser beams are being emitted, a stationary beam with fixed position on the work piece and a movable beam that can be positioned relative to the stationary beam. A very effective solution with high spatial resolution and fast actuation was developed for steering the movable laser beam. The movable beam cannot only be set to a fixed position but it can also be scanned at high frequencies. The power of both beams is individually controlled. Ongoing process investigations and future MB-LAM target specific applications for vehicles, jet engines and medical devices serving the automotive, aerospace, medical and defence sector. Initial results are being presented.Today, Laser Additive Manufacturing (LAM) is typically performed using a single beam with power up to multiple-kilowatts. The associated high heat input and limited process control hampers tight manufacturing tolerances and the applicable material spectrum. This paper highlights the development of Multi-beam LAM technology to address the shortfalls of today’s technology and to broaden the applicability to many industries. Multi-beam LAM deploys several low power beams, each precisely controllable with a minimum heat input thus providing the capability to tailor the applied energy to the specific needs of the application. The single beams either work in parallel to scale productivity without sacrificing precision or in close proximity creating desired heat profiles. This new approach is scalable in productivity through multiplication and is expected to allow deposition of difficult to coat materials through tailored heat profiles. Advances are expected in near net shape manufacturing of complex structures ...

Today many challenges lie ahead of the aircraft industry. The increasing competition and shortage of resources raise a challenge for future manufacturing technologies and lightweight design. A possibility to cope with these circumstances is the manufacturing technology of Laser Additive Manufacturing (LAM). However there are still challenges to cope with due to the processes novelty, such as the development of further materials, especially lightweight alloys, and new design approaches. Therefore innovative approaches for material development and lightweight design were created in order to fully exploit the processes potentials. The material development process is based on an analytical calculation of temperature distribution versus effective process factors in order to identify acceptable operating conditions for the LAM process. A novel approach to extreme lightweight design was realized by incorporating structural optimization tools and bionic structures into one design process. By consequently following these design principles, designers can achieve lightweight savings in designing new aircraft structure and push lightweight design to new limits.

Additive Manufacturing (AM), likewise branded as 3D printing, is a field of significant interest that has been recognized as an advanced process for production of engineering components in a layer-by-layer approach. It both offers an alternative fabrication route for existing designs, as well as enables new designs with complexity unattainable using conventional techniques. Amongst different AM processing routes, Laser Additive Manufacturing (LAM) is one of the supreme encouraging additive manufacturing means due to the potential to fabricate products at low cost with high quality and productivity. Considering many studies are in progress in this new and exciting field, this review paper argues the present state of the art and considers new avenues for future research studies. It explores the key metallurgical phenomena during LAM and the differences between various routes of LAM technology in terms of powder bed fusion (PBF) or directed energy deposition (DED) involving different forms of powder-bed, powder-fed, and wire-fed assembly. The reported microstructural aspects, functional, and mechanical properties of advanced and high applicable materials classified as stainless steels, nickel-based and superalloys, titanium-based alloys, and metal matrix composites (MMCs) for various practical applications are highlighted along with the effects of different pre- and post-treatment characteristics. Hereafter an evaluation of the field is provided; the gaps in the scientific understanding are underlined, which may limit the growth of LAM technology for the design of metallic parts.

Laser additive technology additive manufacturing is a manufacturing method that realizes the combination of precise "shape control" of complex structure and high-performance "controllability". After rapid solidification, it forms a surface coating or matrix structure with very low dilution. Such surface coating or structure can effectively combine metallurgical technology, and can improve the wear resistance, corrosion resistance, heat resistance, oxidation resistance and other properties of the surface of the matrix material, or in manufacturing. At present, laser additive manufacturing is widely used in aerospace and military industry for rapid repair and performance enhancement of parts. In terms of metals, selective laser melting (SLM) and laser melting deposition (LCD) processes are mainly represented.

Overview of Sustainability Studies of CNC Machining and LAM of Stainless Steel

Additive Manufacturing (AM) offers lots of advantages when compared to other manufacturing processes, such as high flexibility and ability to produce complex parts directly from the Three Dimensional (3D) Computer-Aided Design (CAD) model. Producing highly complex parts using traditional manufacturing processes is difficult, and it requires it to be broken down into smaller parts, which consumes lots of materials and time. If this part needs to have a surface with improved property or a surface made of composite materials, it has to be done by employing another manufacturing process after the parts are completed. AM, on the other hand, has the ability to produce parts with the required surface property in a single manufacturing run. Out of all the AM technologies, Laser Additive Manufacturing (LAM) is the most commonly used technique, especially for metal processing. LAM uses the coherent and collimated properties of the laser beam to fuse, melt, or cut materials according to the profile generated from the CAD image of the part being made. Some of the LAM techniques and their mode of operations are highlighted in this chapter. The capabilities of using LAM for surface modification of metals are also presented in this chapter. A specific example is given as a case study for the surface modification of titanium alloy (Ti6Al4V) with Ti6Al4V/TiC composite using laser material deposition process – an important LAM technology. Ti6Al4V is an important aerospace alloy, and it is also used as medical implants because of its corrosion resistance property and its biocompatibility.

Laser Additive Manufacturing of Bio-inspired Metallic Structures