The growing competition in electric mobility is leading to an increased demand for inexpensive, high-performance lithium-ion batteries. In order to meet both objectives, optimization of the entire production chain is indispensable. In this work, the laser cutting of electrodes as one of the core processes in large-format battery production is addressed. A comprehensive literature review on the boundary

Direct laser metal deposition of a medium carbon low alloy steel was performed on a round bar sample. Taguchi design was used to investigate the effect of three process parameters with three different levels on the microstructure and properties of single- and multitrack clad samples. Microstructural analysis showed that coalesced bainite and lath martensite exist in the clad area. Two different kinds

Near-infrared lasers, which are mainly used in the SLM (selective laser melting) method at present, have a low absorption rate for copper, making it difficult to fabricate a 3D structure of copper. To solve this problem, we have developed a new 200 W blue diode laser (wavelength: 450 nm), that has a high absorption rate for copper. The SLM system with the blue diode laser has been developed. In addition

The productivity and quality of laser micromachining depend on multiple laser parameters that are intricately correlated. For these optimizations, a quick survey of laser parameters is vital. Recently, the authors developed a Yb-doped fiber chirped-pulse amplification system that can control various laser parameters in a wide range (pulse duration: 0.4–400 ps, repetition: single shot to 1 MHz, etc

Numerous sensing modalities have been utilized to monitor metal additive manufacturing, thus assessing process stability and build quality. One common directed energy deposition sensing method is coaxial “melt pool” imaging, wherein a camera mounted coaxially with the laser-focusing optics views the laser-interaction zone via a dichroic mirror. This work demonstrates that coaxial “melt pool” imaging

The laser impulse metal bonding (LIMBO) process is a novel laser spot welding process to form a weld joint between a massive interconnector and thin metallization on a thermally sensitive substrate. As for the LIMBO process, the gap between joining partners in overlap configuration allows energetic separation of the melting and joining processes, whereas the underlying joining partner is only thermally

In this paper, an additive manufacturing process has been used to deposit nanoparticles on a substrate. In this innovative technique called the nano-electrospray laser deposition process, droplets of various nanosuspensions are dispensed onto a silicon substrate where subwavelength structures and bouncing droplets have been observed. An analytical model is presented for determining the temperature

Pure copper rods were additively fabricated by using a multibeam type laser metal deposition (LMD) device equipped with two blue diode lasers, and the influence of them on the rods was investigated. It is unknown how the rod changes with respect to the process parameters such as the laser power and the powder feeding rate. In this study, the laser power and the powder feeding rate were changed to form

Titanium dioxide (TiO2) has been a key material in a wide range of applications such as catalysis, energy harvesting, and antibacterial surfaces. Typically, different TiO2 phases are first synthesized and then coated onto the test parts. Here, the authors demonstrate a direct method for the formation of TiO2 nanostructures and patterns with rutile, anatase, and mixed phases by a controlled laser-assisted

The hot section parts in a gas turbine are subject to high working temperatures and mechanical forces. In order to endure the harsh conditions, these parts are generally made of nickel-based superalloys. Furthermore, microholes are drilled on them to help with cooling by allowing the air to pass through. These holes increase the allowable working temperature and service life of the parts as well. Water

Laser processing of metallic thin sheets has gained undoubted industrial interest in the last decade especially due to its implications in the e-mobility field. In particular, dissimilar welding of thin sheets made of different materials, such as aluminum, copper, and steel is nowadays recognized as an effective solution for many joining applications in battery and related component production. According

To improve printing results, a printing form can be functionalized and the material transferring behavior can be adjusted. In this work, a flexographic printing form is divided into three different areas: first the elevated, material transferring structures (1); second the rising edges between the printing form substrate and the elevated structures (2); and third the transition area (3) between (1)

Transparent spinel ceramics were additively manufactured by laser direct deposition, a blown powder additive manufacturing (AM) process. With a laser melt-growth process, the need for powder binders and postprocessing procedures was eliminated. Transparent spinel ceramic samples were directly fabricated from micrometer-size magnesium aluminate spinel powders. The optical transparency of the printed

Laser material deposition (LMD) is a process in which a laser beam creates a melt pool on the surface of a substrate while a powder nozzle delivers a powdered additive into the melt pool, where the powder material then melts. A dense, metallurgically bonded layer forms once the melt solidifies. The velocity of powder particles in LMD is one of the key factors that influence the amount of particles’

Polymers were one of the first materials to be processed by ultrafast lasers. However, the nature of absorption for near-infrared laser beams is not fully understood, and therefore it remains challenging to process polymeric materials with high energy efficiency. In this study, the pulse-to-pulse evolution of optical properties (reflectance, transmittance, and absorptance) of polypropylene (PP), which

Extreme high-speed laser material deposition (EHLA) is a variant of laser material deposition (LMD) with a modified powder gas jet focus. EHLA allows deposition at high process speeds in the range of several hundred meters per minute and the deposition of layers as thin as 25 μm. Feed rates can be in the range of 50 g/min or above. The processing of material combinations with poor weldability or different

In the fiber laser cutting of steel with nitrogen assist gas, the effect of positional relationship between the centers of a nozzle and a laser beam on the cutting quality was investigated by laser cutting experiments and computational fluid dynamics analysis of the assist gas flow. The laser cutting experiment of 3.2 mm cold rolled steel was carried out by a 3 kW fiber laser. The spot diameter of

To understand the physics of double-pulse femtosecond laser ablation of metals, the authors have proposed and implemented a new ablation method for measuring the temporal change in the laser penetration length (LPL). The measurements were performed for titanium and platinum with femtosecond laser pulses with a central wavelength of 810 nm, a repetition rate of 10 Hz, and a pulse duration of 45 fs.

A Finite element model is developed with a commercial code to investigate the keyhole dynamics and stability at keyhole threshold, a fusion regime characteristic to laser microwelding or to Laser Powder Bed Fusion. The model includes relevant physics to treat the hydrodynamic problems—surface tension, Marangoni stress, and recoil pressure—as well as a self-consistent ray-tracing algorithm to account

Investigating the wettability of the tool surface made of cemented carbide is of great significance to improve its working life and quality. The micropit array was processed on the surface of cemented carbide YT15 by a 1064 nm femtosecond pulse laser. Then, the optical microscope, the optical profilometer, and the contact angle measuring instrument were applied to measure the surface morphology and

In recent years, laser processes have taken an ever-increasing market share in the manufacture of components. The development of new, improved beam sources with corresponding systems technology and the decreasing investment costs of the beam sources are important keys to this success. Particularly, high frequency beam oscillation has great potential in laser beam welding and cutting. The main obstacle

Oscillating laser hot-wire tungsten inert gas (TIG) hybrid welding of 10 mm thick 316LN austenitic stainless steel in the vertical position was performed. The characteristics of droplet transfer, molten pool formation, and forming mechanism of different oscillating parameters were investigated by the experimental method. A high-speed camera was employed to observe the arc, droplet transfer, and molten

This paper addresses in-process monitoring of weld penetration depth (WPD) during remote laser welding of battery tab connectors using optical coherence tomography (OCT). The research aims at studying the impact of welding process parameters on the accuracy of WPD measurements. In general, the highest measurement accuracy is achievable by positioning the OCT measuring beam toward the bottom of the

Conventional infrared lasers (1070 nm) are not ideal for processing materials such as copper or gold. The reason for this is the corresponding high reflectivity of the aforementioned materials for infrared radiation. Since 2017, so-called “green lasers” {wavelengths around 500 nm [Kaliudis, see https://www.trumpf.com/de_DE/magazin/gruene-welle-fuers-kupferschweissen/ for “Grüne Welle fürs Kupferschweißen

In manufacturing, there is increasing recognition of the need to increase energy efficiency, both to reduce process cost and improve carbon footprint. In order to achieve this, it is necessary to understand how manufacturing systems use energy directly and indirectly. These types of analyses have been carried out at the process level for traditional machining processes, as well as at the factory level

A titanium alloy (Ti64) has α + β crystal orientations, and the β phase mainly appears in the SLM process since Ti64 melts above 1600 °C by laser irradiation and then solidifies. In order to control the crystal orientation and crystal grain size, the modulated pulse of laser was employed to control the heat input energy of laser in the SLM process in this study. After fabrication, the sample was cut

A laser beam oscillation method using Galvano mirrors, which allows wide weld beads and controls thermal stress distribution, was suggested to suppress the formation of solidification cracks in laser welds. In order to understand the solidification cracking behavior in relation to the bead shape, laser beam oscillation welding was performed under various oscillation widths and frequency conditions

Additive manufacturing (AM), often referred to as 3D printing, is a generic term describing the layered build-up of material in near net shape frequently attributed with a freedom of design that cannot be achieved otherwise. AM focuses basically on the fabrication of parts for different fields in complex high-tech applications. Examples include components for jet engines, turbines blades, and implants

Silver nanoparticle-based electrodes were studied extensively in recent years as an electrode material for wearable and flexible electronics due to their stability and conductivity. A wet chemical deposition technique is considered as a low-cost scalable technique. The current wet chemical-based nanoparticle deposition techniques include electrospray deposition, drop casting, spin coating, and the

Molten pool geometry, whose surface parameters may be extrapolated through direct process observations, has been identified as a fundamental indicator of stability in laser powder bed fusion (LPBF). However, a parameter that cannot be directly measured on industrial systems by means of conventional sensing equipment is the molten pool depth. Indeed, methods based on x-ray imaging demonstrated in the

Laser welding is one of the most promising joining techniques to realize hybrid joints between metals and polymers in order to achieve weight reduction and functionalization of the parts. The surface treatment of the metal has a decisive effect on the joint quality and thus on the mechanical properties. In the present study, different mechanical and laser-based surface treatments have been investigated

Laser joining of dissimilar metals, copper and aluminum, allows for the precise delivery of laser energy and high process speed. The keyhole-based process is very efficient for welding Al–Cu, considering the high reflectivity and thermal conductivity of the materials joined. For the Al–Cu system, the formation of detrimental intermetallic compounds is the main issue. Fusion welding with laser as a

Laser welding is one of the most common technologies with various applications in different industries. In this paper, laser joining of the Ti6Al4V alloy and polyethylene terephthalate (PET) as a means of two common materials is discussed. According to the experimental results, the focal length is a very important parameter in this dissimilar laser welding, and because of the low melting point of PET

Cu2ZnSnS4 (CZTS) nanoparticles were successfully prepared by laser ablation in liquid. CZTS powders were irradiated with nanosecond-pulsed laser (Nd:YAG, second harmonic generation) to prepare nanoparticles. The primary particle size of prepared nanoparticles was decreased with the increase in laser fluence, and the decrease was saturated around 11 nm. The secondary particle size of them was increased

Microfabrication based on two-photon polymerization (TPP) is typically achieved by scanning a focal spot point-by-point. This is a type of serial processing that significantly limits fabrication speed. Bessel beams known for their nondiffracting property are suitable for the fabrication of high-aspect-ratio microstructures without scanning the beams. The zero-order Bessel beam generated by an axicon

Laser based Direct Energy Deposition (DED), also called Laser Metal Deposition (LMD), is a process that is widely used for cladding and repair applications and increasingly for additive manufacturing processes [Chen Hong, Dongdong Gu, Donghua Dai, Andres Gasser, Andreas Weisheit, Ingomar Kelbassa, Minlin Zhong, and Reinhart Poprawe, Opt. Laser Technol. 54, 98–109 (2013)]. Its controlled energy input

A vacuum environment results in a deep penetration depth in laser keyhole welding. In this study, the numerical simulations of laser keyhole welding in various vacuum conditions were performed with consideration for multiphysics phenomena. To consider the vacuum environment in numerical simulations, a modified recoil pressure model with the change in pressure and vaporization temperature according

Laser-microdroplet interactions influence the quality of nanoparticle deposition on a substrate. When a microdroplet and its impinging spot are heated, the microdroplet can evaporate gently, boil immediately after impingement, or bounces back inhibiting the deposition process. The interaction between a laser and droplets carrying semiconductor and metal nanoparticles is studied for different laser

Industrialization of directed energy deposition (DED) process relies on the development and implementation of a quality assurance system that makes the process reliable and repetitive. One of the geometrical characteristics that needs constant monitoring and control during any DED process is the height of the deposited layer. In this paper, a multidirectional layer height monitoring system relying

Additive manufacturing technologies such as laser material deposition (LMD) enable manufacturers to economically produce complex and individualized products. However, improved productivity and more economic use of LMD are necessary to benefit from these advantages in a wider range of applications. Through the use of industrial robots in LMD applications, large workspaces and geometric flexibility can

A three-dimensional numerical simulation model is developed in this paper to analyze the symmetry of weld geometry and the homogeneity of alloy distribution in the molten pool during the dissimilar fiber laser welding of low carbon steel and stainless steel during different welding conditions. The simulated results are compared with the experimental results and good agreement has been obtained. The

In order to study the interaction between a femtosecond laser and a titanium film, the method of combining the two-temperature model and molecular dynamics was used to simulate the ablation and spallation of the titanium film by the femtosecond laser with a wavelength of 800 nm. The spallation of the titanium film was explained from the perspective of the temperature and the stress wave. It is found

Laser processing is widely used in the manufacture of surface patterns. However, it faces new challenges under some industrial demands. For example, the fine cladding circuit requires that the metal layer is precisely etched in depth for slight damage to the substrate and the formed conductive tracks have vertical sidewalls for higher precision. The former can be achieved by a reasonable control of

The service performance of U75V rail steel depends entirely on its laser-deposited microstructure, as coarse martensite has a damaging effect on wheel-rail contact behaviors. In this study, the formation mechanism of the microstructure in the rail steel was investigated based on simulated temperature fields in both solid and annular laser heat source models. U75V rail steel with pearlite was first

With the rapid development of laser technology, the protection of production equipment and personnel is of great necessity. Thermal barrier laser protection material has the advantages of a high protection threshold and a low temperature increasing rate that attracts lots of concerns. Ba2–xSrxSmTaO6 (x = 0–2) was believed to have potential use as a thermal barrier laser protection material because

Laser metal deposition (LMD) is getting more attention as a 3D printing technique recently. Compared to the cladding application, the process of building 3D structures is more challenging to control when it comes to complex structures. Changing heat transfer mechanisms over the building height and at critical part geometries can lead to instabilities during the process. This paper studies the effect

This paper describes the research conducted on the automation for a UV laser-based surface pretreatment of fiber-reinforced composites in order to improve adhesive bonding conditions. In a preceding process step, a laser-line-triangulation system gathered inline information on a composite part’s surface like topology and location of surface contaminants. These data are the basis for an automation of

In fast neutron reactors, contact areas of moving parts usually require cobalt-free hardfacing coatings, as cobalt is highly activated under neutron flux. This is particularly critical for the insert holes of the diagrid for the positioning of the hexagonal fuel tubes that have to be internally coated. In this article, we propose to present the development of the cobalt-free hardfacing material up

A polyvinyl alcohol/tin chromium disulphide (PVA/Sn0.75Cr0.25S2) nanocomposite (NCP) was synthesized by the thermolysis and casting routes. The resulted effect of laser, within fluences 2–28 J/cm2, on the structural and optical characterization of PVA/Sn0.75Cr0.25S2 NCP, was inspected by using XRD, FTIR, and UV spectroscopes. Additionally, the optical bandgap reduced from 3.47 to 2.77 eV on increasing

The depth homogeneity of laser-treated zones is one possible factor to define the quality and efficacy of altered mechanical properties in materials. For instance, half-rounded cross-sectional shapes of laser hardened zones using Gaussian beams provide dissimilar hardened depth in the edges and center of the treated area. This means that the in-depth distribution of compressive residual stress varies

Direct metal laser sintering is a kind of laser powder bed fusion process that emerged as an advanced manufacturing process in the recent era of industry 4.0. This is a rapid manufacturing process where repeated melting and solidification takes place during scanning of the powder bed. The characteristics of the as-built component depend on the melting and solidification behavior which is directly influenced

The microstructural optimization of lithium-ion battery (LiB) electrodes has recently gained a lot of interest. Versatile approaches to enhance fast charging abilities of LiB electrodes are the subject of current research. One of these approaches is the laser based photothermic removal of superficial inactive electrode components in order to improve the accessibility of the active material particles

The effect of pulsed laser polishing on rough niobium surfaces was investigated. We created different well-defined roughness profiles with standard emery papers and subsequently remelted random surface areas with a size of about 2 × 2 mm2 with nanosecond laser pulses (wavelength of 1064 nm, pulse length of 10 ns). Pristine as well as laser-treated surfaces were investigated using optical profilometry

A laser hazard evaluation compares the potential laser exposure to the maximum permissible exposure (MPE). Direct intrabeam viewing of a collimated laser beam produces a minimally sized retinal image. Viewing other laser sources often produces a larger retinal image known as an extended source. An optical limiter is designed to protect the eye from direct laser exposure through a combination of absorption

This paper presents an investigation into the influence of laser drilling on the tensile strength of carbon fiber reinforced plastic (CFRP) laminates of 1 and 2.5 mm thickness. The CFRP laminates were drilled using the microsecond laser, nanosecond laser, and picosecond laser, and the heat-affected zone (HAZ) was characterized and measured by optical microscopy. Through setting laser parameters, specimens

Aluminum alloy is considered to be one of the ideal materials for light-weighting on aerospace and new energy automotive. Laser welding without a filler wire is an efficient way for weight reduction. The common defects in laser welding of aluminum alloys are porosities and cracks, resulting in poor mechanical performances and short service life of joints. In order to investigate the methods to suppress

Laser selective metallization of ceramics (LMC) has been widely applied to prepare high-quality electrical patterns on ceramic circuit carriers. As the dominating factor, surface roughness after laser treatment is controlled mostly by the laser technical parameters, such as laser power, scanning velocity, and laser frequency. Therefore, establishing an accurate relation between the surface roughness

The temperature distribution characteristics of a moving annular hollow laser beam irradiated on the substrate are studied in this paper. First, through the linear superposition property of potential function, we derive the analytical solution of temperature distribution and the cooling rate of the moving ideal annular hollow heat source. The entransy dissipation rate per unit volume of the annular

Commonly, the low wear resistance of stainless steels damages them during usage; in order to enhance wear properties, various types of tungsten-carbide-based coatings, such as WC-Co and WC-Ni, could be applied on the steel surface. To improve the mechanical properties of the coatings, instead of nickel- or cobalt-bearing coatings, WC-FeAl composite coating is used. Following the previous studies on

Laser cutting of metals has become the reference manufacturing technology in sheet metal working thanks to the flexibility and the increased productivity it offers when compared with other competitive technologies. Considering, in particular, the fusion-cutting mode, i.e., when nitrogen is used as an assisting gas, different aspects contribute to the process quality among which dross attachment plays