Laser Powder Bed Fusion Materials Research Articles

Microstructure evolution in laser powder bed fusion melted 2205 duplex stainless steel using in-situ EBSD during uniaxial tensile testing

Compared to duplex stainless steels (DSSs) prepared by traditional methods, specimens produced through laser powder bed fusion (LPBF) exhibit excellent yield strength but lower elongation. To improve elongation, understanding microstructure evolution during uniaxial tensile testing is crucial. This study investigates the slip behavior, grain boundary evolution, and phase transformation of LPBF 2205 duplex stainless steel during tensile deformation using in-situ electron backscatter diffraction (EBSD). Results show the formation of slip bands, which increase in number as loading stress rises. The primary slip systems activated are {110}<111> in ferrite and {111}<110> in austenite. In the ferrite phase, slip dislocations accumulate and generate low-angle grain boundaries (LAGBs), which evolve into high-angle grain boundaries (HAGBs), refining the grain structure. Numerous Σ3 annealing twins form in the austenite phase, but detwinning and twinning reduce Σ3 content as deformation processes. Ferrite and austenite exhibit good stability during the initial stages of tensile deformation. However, some austenite transforms into martensite through the transformation-induced plasticity (TRIP) effect at the final stages of deformation, which helps relieve stress concentration and delays material fracture. This study provides valuable insights for optimizing microstructure to improve the mechanical properties of LPBF materials.

A comparison of conventional and additively manufactured 316L under thermomechanical fatigue

The present study compares the thermomechanical fatigue (TMF) behaviour of 316L stainless steel manufactured conventionally by hot rolling and additively by laser powder bed fusion (L-PBF). Machined cylindrical specimens were tested under strain-controlled in-phase and out-of-phase TMF loading at a temperature range of 550–750 °C and total mechanical strain amplitudes of εamech = 0.2–0.6 %. While the conventional 316L significantly outperforms the L-PBF 316L under in-phase TMF, their lifetimes are comparable under out-of-phase TMF. Under in-phase TMF, creep damage in the form of intergranular crack networks occurs which is significantly more pronounced for the L-PBF 316L due to the higher amount of interfaces. Under out-of-phase TMF, the damage is mostly due to stress-assisted oxide cracking and the crack propagation is fatigue-dominated. TEM inspection revealed that L-PBF 316L exhibits a cellular dislocation structure in the initial state, which rearranges only slightly during cycling. For conventional 316L similar dislocation cells form during TMF cycling indicating that they represent a stable dislocation arrangement in 316L under TMF loading. This is evidenced by the rather stable cyclic stress response of the L-PBF material when compared to the conventional material.

Fatigue life prediction model for shot-peened laser powder bed fused 304L steel considering residual stress relaxation and defect distribution

Shot peening (SP) is a post-treatment technology that enhances the surface smoothness, mechanical properties, and fatigue performance at the surface layer of metal materials produced through laser powder bed fusion (LPBF). Therefore, accurate life prediction is crucial to effectively design and evaluate the SP process and enhance fatigue life. This study employs a cost-effective and efficient analytical method to investigate relaxation in residual stress (RS). The method calculates the interaction between RS in SP and external loading and combines it with a life prediction model. In addition, a defect-based parameter area is employed to characterize the impact of the effective defect dimensions on the fatigue life of LPBF materials. The effects of compressive residual stress (CRS) introduced by SP and process-induced internal defects on the fatigue life of LPBF material are investigated via a modified Goodman‐Basquin model. The fatigue life of 304L stainless steel (SS) prepared by LPBF after SP is predicted, and good consistency between measurement and prediction is observed.

Influence of Post-processing and Build Direction on the Wear Behaviour of Laser Powder Bed Fused Maraging Steel

Abstract Present study investigates the effect of post processing (heat treatment: solutionising at 850°C for 2 hr with aging at 490°C for 3 hr and cryogenic treatment at -196°C for 24 hr) and the effect of build direction (along the build direction (BD) and perpendicular to the build direction (PBD)) on the wear behavior of maraging steel fabricated by Laser powder bed fusion (LPBF). The results are also compared with conventional hot-forged samples. The pin on disc equipment was used to conduct the wear experiments with an EN31 steel disk as the counter body. Heat treatment decreased the wear rate of LPBF material by 54.78% and 83.84% in BD and PBD, respectively. This is due to the restriction of grain expansion by the Ni-based precipitants in age hardening treatment. The cryogenic treatment further decreased the wear rate of LPBF material by 87.84% and 90.9% in BD and PBD, respectively. This significant reduction can be attributed to the change of phase to martensite, as confirmed through microstructure and X-ray diffraction (XRD) analysis. Moreover, hot forged material also obtained a reduced wear rate after heat and cryogenic treatments. The highest wear resistance was found with the LPBF cryo-treated BD sample due to increased hardness from 388 HV to 640 HV. The worn surface of test samples was examined by using scanning electron microscopy (SEM), energy dispersive X-ray (EDX), 3D profilometer, and XRD analysis. Oxidation wear, adhesive wear, and abrasive wear are the predominant wear mechanisms identified using SEM.

Additively manufactured Ti‐6Al‐4V microstructure tailoring for improved fatigue life performance

AbstractIn this study, laser powder bed fusion (LPBF)‐produced Ti‐6Al‐4V is subjected to three separate post‐build heat treatments (HTs), specifically (1) a one‐step annealing HT exceeding the ‐transus temperature, (2) a two‐step annealing HT whose first step exceeds the ‐transus temperature and the second step is an anneal below the ‐transus temperature, and (3) a sawtooth HT with temperatures oscillating below the ‐transus temperature. Tensile properties and fatigue crack growth behavior were assessed and compared to wrought Ti‐6Al‐4V. LPBF materials nominally exhibited a 17% yield stress reduction, 1.9% strain‐to‐failure increase, and 9.2% modulus of toughness decrease. Fatigue crack growth curves were used to assess the linear crack growth rate region and approximate fracture toughness ( ). Post‐mortem fractography observed striations indicating the crack growth direction frequently changes direction providing an understanding of the slower crack growth rates observed in LPBF materials compared to their wrought counterpart.

Measuring the tensile properties of Ti6Al4V fabricated by laser powder bed fusion: Influence of specimen dimensions

This study presents the mechanical characterization of vertical Ti6Al4V tensile specimens produced by laser powder bed fusion (LPBF) processing and then heat-treated according to AMS2801 standard. The surfaces were kept in the as-built condition for the evaluations. Three rectangular specimen geometries were considered, with a reduced section of 6 × 6 × 25, 3 × 3 × 12.5, and 1 × 1.5 × 7 mm3 respectively. The surface roughness, length-scale of the microstructure, and average microhardness were compared and found to be unaffected by part section, in the range of sizes explored. The non-destructive measurement of the cross-sectional area of the tested specimens affected the accuracy on the measurement of the tensile strength. The use of conventional tools, such as calipers and micrometers, led to an overestimation of the cross-sectional area by 7 to 15 %, which caused an underestimation of the tensile stresses. When calculating the stress with the cross-sectional area measured from computed tomography images, the Young’s modulus, yield strength and ultimate tensile strength were comparable for all geometries. However, the elongation at break was 9 % for the smallest specimens compared to 12 % for ASTM E8 coupons. The reduction of ductility was explained by a higher slimness ratio for smaller specimens, in addition to an increased effect of pores and the surface roughness. These results highlight the importance of using specimens representative of a part wall thickness when characterizing the mechanical properties of LPBF Ti6Al4V. The methodological recommendations established in this study can be applied to other LPBF materials and other small scale manufacturing processes.

Critical role of slags in pitting corrosion of additively manufactured stainless steel in simulated seawater

Pitting corrosion in seawater is one of the most difficult forms of corrosion to identify and control. A workhorse material for marine applications, 316L stainless steel (316L SS) is known to balance resistance to pitting with good mechanical properties. The advent of additive manufacturing (AM), particularly laser powder bed fusion (LPBF), has prompted numerous microstructural and mechanical investigations of LPBF 316L SS; however, the origins of pitting corrosion on as-built surfaces is unknown, despite their utmost importance for certification of LPBF 316L SS prior to fielding. Here, we show that Mn-rich silicate slags are responsible for pitting of the as-built LPBF material in sodium chloride due to their introduction of deleterious defects such as cracks or surface oxide heterogeneities. In addition, we explain how slags are formed in the liquid metal and deposited at the as-built surfaces using high-fidelity melt pool simulations. Our work uncovers how LPBF changes surface oxides due to rapid solidification and high-temperature oxidation, leading to fundamentally different pitting corrosion mechanisms.

Crystal plasticity simulations with representative volume element of as-build laser powder bed fusion materials

Additive manufacturing of as-build metal materials with laser powder bed fusion typically leads to the formations of various chemical phases and their corresponding microstructure types. Such microstructures have very complex shape and size anisotropic distributions due to the history of the laser heat gradients and scanning patterns. With higher complexity compared to the post-heat-treated materials, the synthetic volume reconstruction of as-build materials for accurate modelling of their mechanical properties is a serious challenge. Here, we present an example of complete workflow pipeline for such nontrivial task. It takes into account the statistical distributions of microstructures: object sizes for each phase, several shape parameters for each microstructure type, and their morphological and crystallographic orientations. In principle, each step in the pipeline, including the parameters in the crystal plasticity model, can be fine-tuned to achieve suitable correspondence between experimental and synthetic microstructures as well as between experimental stress–strain curves and simulated results. To our best knowledge, this work represents an example of the most challenging synthetic volume reconstruction for as-build additive manufacturing materials to date.

Creep Characterization of Inconel 718 Lattice Metamaterials Manufactured by Laser Powder Bed Fusion

Lattice metamaterials manufactured by laser powder bed fusion (LPBF) are limited by their performance for critical applications. LPBF materials have microstructural or macroscale anomalies, such as suboptimal grain size, morphology, and lack of fusion. This results in LPBF metamaterials performance degradation for various mechanical properties, such as creep, which has seldom been researched. To understand the creep behavior of LPBF Inconel 718, body‐centered cubic metamaterials are fabricated for creep test at 650 °C. Kachanov's damage modeling is used to predict the creep performance of the metamaterials under different loading conditions. Microstructural characterization is performed with scanning electron microscopy to identify critical microstructure defects affecting the failure mechanisms and creep behaviors of the metamaterials. It is shown in the results that the loading conditions affect the fracture process of the metamaterials owing to different failure mechanisms. In the simulation and test results, the logarithmic decline in creep life is shown when loading increases; also, logarithmic increase in the creep life is shown when relative density increases.

Effects of process parameters and scan strategy on the microstructure and density of stainless steel 316 L produced via laser powder bed fusion

The ability to produce reliable and reproducible components from 316 L using additive manufacturing is crucial to serve the need for customization, on-demand manufacturing and reduced lead times for various industries. Laser powder bed fusion is becoming widely accepted as a versatile additive manufacturing technique capable of producing near defect-free components with tailored microstructures and mechanical properties. However, despite the recent progress in process parameter selection and optimization, even a small change in any of the laser parameters, equipment and feedstock powder characteristics can influence the microstructure and subsequently the mechanical properties of the fabricated parts. The purpose of this work is to tackle the process optimization challenge through, a full factorial design of experiments approach, to systematically assess the widely adopted energy density factor to evaluate the density of the final component. A statistical approach was also followed to evaluate potential plastic anisotropy in different samples produced with various energy densities and scan strategies. Density measurements indicated that beyond laser power and scan speed, the interaction effects of the aforementioned parameters with the layer thickness and the powder size distribution have a significant effect on the sample. Microstructural features such as melt pools, grains and crystallographic texture were characterized against a range of volumetric energy densities and scan strategies represented by different angles of rotation between successive layers. Smaller angles of rotation per layer were found to decrease texture anisotropy and suppress the formation of keyhole porosity in finer and more homogenous microstructures. The assessment of plastic anisotropy in the produced samples was evaluated using microhardness measurements on all three orthogonal planes of the samples. The hierarchical microstructure of laser powder bed fusion materials induces several strengthening mechanisms, that can simultaneously be activated depending on the loading scenario, location and plane.

Microstructure formation during laser powder bed fusion of Ti-22Al-25Nb with low and high pre-heating temperatures

We compare microstructure formation during laser powder bed fusion (LPBF) of a Ti-22Al-25Nb alloy applying low and high pre-heating build plate temperatures. Fast cooling rates during low-temperature LPBF lead to metastable weakly ordered β phase, i.e., bcc–(Ti,Al,Nb) with pronounced 〈100〉 texture in build direction and nanosized segregations within grains elongated in the build direction. For high-temperature LPBF a Widmanstätten microstructure was observed with lenticular O phase precipitates within the β matrix. Microscopical and in situ high-energy synchrotron diffraction investigations demonstrate that the microstructure formation can be widely explained by the precipitation of O phase from supersaturated β rather than by a sequence of solid-state phase transformations, as it would be expected under thermodynamic equilibrium conditions. A detailed analysis of the microstructural gradient in the subsurface region, however, demonstrates that precipitation from metastable β cannot fully explain the observed microstructures, and that the process energy density, i.e., the intensity of the intrinsic heat treatment of LPBF, plays a relevant role. The investigation of the graded area near the surface of the LPBF materials produced with high pre-heating temperature is particularly interesting as it reveals preferred nucleation of the O phase at subgrain boundaries and dislocations.

Effect of 316L Stainless Steel Fabrication on Oxidation Resistance, Surface Morphology, and Hot Tensile Behavior

Samples based on 316L stainless steel were prepared by conventional manufacturing process (CM) and laser powder bed fusion (L-PBF). Surface morphology changes under air oxidation in the temperature range 600-900 °C were carried out. Tensile tests were carried out in the temperature range of 700-900 °C for strain rates between 0.001 and 0.1 s−1. The materials showed good oxidation resistance up to 700 °C. The CM and L-PBF material had a high mass gain instability and similar microstructures developed under high temperatures were found in both alloys. Increased temperature increases Cr concertation in the L-PBF material up to 40 at.% at 800 °C and a rich Fe based oxide is formed at 900 °C. Slightly thicker oxide scales were formed in the CM than in the L-PBF material.The hot tensile tests reveal that a fast work hardening occurs for all hot tensile tested samples up to a strain of approximately 0.025. Low temperatures and high strain rates within the investigated range promote a second work hardening regime, while a plateau in the flow stress is observed at high temperatures and low strain rates. The highest yield stress and peak stress values are reached at 700 °C. The yield stress is nearly independent of the strain rate at 700 °C. It decreases with a decrease in strain rate for 800 and 900 °C, and it decreases with an increase in temperature. The elongation till fracture varies from 10 to 22%, and it is strongly influenced by defects inherent of the L-PBF process.

On the origin of the strain hardening mechanisms of Ni20Cr alloy manufactured by laser powder bed fusion

Additively Manufactured (AM) metallic alloys differ from their conventionally produced counterparts by complex multi-scaled microstructures leading to deeply modified mechanical behavior. The characterization of these new links between microstructure and mechanical properties is of first importance. Nevertheless, many alloys produced by Laser Powder Bed Fusion (LPBF) process exhibit multi-phase microstructures which makes difficult the understanding of these links. In this article, we aimed at simplifying this complexity by investigating the basic strain hardening mechanisms of AM (LPBF) alloys of a theoretically monophasic Ni20Cr alloy manufactured by laser powder bed fusion. Based on the analysis of the microstructure and the tensile mechanical behavior including loading-unloading-relaxation tests, a comparison with conventionally manufactured Ni20Cr alloy is performed. First, an increase in yield stress for the LPBF samples is observed due to both effective stress and backstress modification. Second, the strain hardening mechanisms are modified for LPBF manufactured samples compared to cast ones. Kocks-Mecking model is then employed to reproduce the tensile curves and better analyze the strain hardening mechanisms. Results are discussed in terms of specific LPBF microstructure feature contributions to stress and strain hardening. We reveal that dislocation cells associated to dendrites are proved to be responsible for about 50% of the improved yield stress of LPBF material and seem to control the dislocation production, forest interactions being inoperative for those materials.

Dissolution kinetics of Laves phase during homogenization heat treatment of additively manufactured Inconel 718 superalloy

The Laves phase in the as-built Inconel 718 (IN718) superalloy is known as undesirable phase, which limits the industrial applications of the manufactured parts. Post-processing in the form of the homogenization heat treatment is known as an effective method to eliminate the deleterious Laves phase, where understanding its dissolution kinetics is crucial for optimization of the heat treatment schedule. Accordingly, the IN718 nickel-based superalloy manufactured by the laser powder bed fusion (LPBF), also known as selective laser melting (SLM), was homogenized at temperatures from 950 to 1150 °C for 30 to 120 s, and the Laves phase dissolution was studied by microstructural analysis, its kinetics was modeled by Johnson-Mehl-Avrami-Kolmogorov (JMAK) analysis, and the model was validated by the second Fick's law. The activation energy for Laves phase dissolution was determined as ∼160 kJ/mol with an Avrami exponent of ∼1, which was attributed to the high dislocation density and fine microstructure of the LPBF material, and accordingly, the lattice and grain boundary diffusion of Nb in Ni were characterized as the underlying atomistic mechanisms during the dissolution of the Laves phase. These findings are based on the underlying atomistic mechanisms, which can shed light on the principles of dissolution kinetics of Laves phase in IN718 for additive manufactured parts. Moreover, the conducted comparison among LPBF, directed energy deposition (DED), and conventional casting indicated that the fabricating method and the initial segregation play key roles. In other words, due to its lower segregation degree, LPBF has faster Laves phase dissolution kinetics in comparison with other fabrication methods.

Comparison of Microstructure and Properties of Nickel-Copper Alloy Prepared by Casting and Laser Powder Bed Fusion Process

Nickel-copper alloys are commonly used in highly corrosive conditions where strength is required. Typical applications are in the marine sector, petrochemical industry, or energy facilities such as chemical tubes, pumps, heat exchangers and superheated steam systems. This paper compares the microstructure and mechanical properties of a cast alloy with a 3D printed alloy processed via a laser powder bed fusion (LPBF) technique. Small cylindrical specimens were used for tensile tests at room temperature (RT) and elevated temperatures up to 750 °C in air. The tensile stress-strain response was determined for both types of materials. At RT, LPBF material has a higher yield strength and ultimate tensile strength than a cast alloy. At elevated temperatures, the strength of both variants is comparable. However, the fracture elongation of the LPBF material is significantly lower over the entire range of investigated temperatures. Fracture surfaces and polished sections parallel to the specimen axis were investigated to compare the microstructure and damage mechanisms of the nickel-coper alloy 400 prepared by conventional casting and via LPBF.

A Comparative Study of Microstructure and Hot Deformability of a Fe–Al–Ta Iron Aluminide Prepared via Additive Manufacturing and Conventional Casting

In this work, the microstructure and hot deformation behavior of laser powder bed fusion (L-PBF) and conventionally cast Fe-25Al-1.5Ta (at.%) alloys were compared. The L-PBF builds recrystallized comparably to the as-cast samples during hot deformation. Nevertheless, distinct differences were observed in the flow behavior characteristics between the as-cast and L-PBF samples. The L-PBF builds exhibited lower flow stress than the as-cast material over the entire deformation conditions tested. The average activation energy of hot deformation (Q) of 344 kJ mol−1 was calculated for the L-PBF build and 385 kJ mol−1 for the cast material. The lower Q indicates lower deformation resistance of the L-PBF sample. The peak work hardening rate (θ) in the L-PBF sample (1.72 × 103 MPa) was significantly smaller than that of the as-cast sample (3.02 × 103 MPa), suggesting that the dislocation glide in the L-PBF sample is less hindered during deformation. Possible sources of the observed differences in the deformation behavior between the L-PBF and cast materials will be discussed. Initial and post-deformation microstructures were characterized using an X-ray diffractometer (XRD) and ultra-high-resolution scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDX) detector. The C14-(Fe, Al)2Ta Laves phase (P63/mmc) was predominantly formed at the A2 α-(Fe, Al) matrix phase grain boundaries in both the as-cast and L-PBF materials. The XRD results suggest that the ordering transition from B2-FeAl to a D03-Fe3Al phase occurs during casting, but rarely during ultra-high-cooling L-PBF processing. In summary, the L-PBF creates samples that are subject to less work hardening and require less deformation resistance, and thus, can be formed by a lower deformation force. It, in turn, reduces the loads imposed on the tooling and dies during the deformation processing, contributing to less wear and the high durability of dies.

On the microstructural evolution and failure mechanism in laser powder bed fusioned Ti–6Al–4V during low cycle fatigue at room and elevated temperatures

Microstructural features and their evolution during cyclic deformation directly impact the low cycle fatigue (LCF) life of additively manufactured Laser Powder Bed Fusion (LPBF) Ti–6Al–4V. Tensile and strain controlled LCF tests were performed at room (RT) and elevated temperature (ET, @ 400 °C) to study the cyclic softening behaviour and failure mechanism of LPBF Ti–6Al–4V. The evolution of α′ grains and free dislocation density were studied using Electron Backscatter Diffraction (EBSD). LPBF Ti–6Al–4V has greater tensile strength than conventionally manufactured wrought Ti–6Al–4V due to its microstructure, with fine α′ needles which provide small slip lengths. For cyclic loading at ET, the interaction between the dislocations increases which in-turn increases the ability of material to overcome the obstacles to dislocation motion, resulting in higher cyclic softening compared to the RT test. During cyclic deformation, evolution of dislocation substructures takes place to subsequently produce Low Angle Boundaries (LABs) inside the prior α’ grains. The LABs progressively lead to nucleation and coalescence of voids with fatigue cycles, eventually leading to fracture. An increase in strain range (i.e. plasticity level) causes more significant dislocation pile-up, contributing to a greater amount of cyclic softening. The lack of fusion voids or pores, present at or near the surface, and microcracks, present at the rough surface, act as the crack initiation locations which propagate to cause fracture of the LPBF material under LCF loading, where the primary mode of fatigue fracture observed is intergranular.

On the effect of building platform material on laser-powder bed fusion of a Ni-base superalloy HAYNES® 282®

Additive manufacturing (AM) by laser powder bed fusion (LPBF) involves melting of layers of powder onto a substrate, called a building platform. Due to cost or convenience considerations, building platform materials rarely match the LPBF material, especially for high temperature materials. To ensure tolerances in component geometries, AM components are often stress-relieved/heat-treated while still attached to the building platform. It is therefore important to understand the effect of dissimilar building platform materials on the properties of the built-up material. These effects may be particularly important for high performance materials such as Ni-base superalloys used for critical applications in the aerospace and energy industries. To investigate this effect, samples of a Ni-base superalloy HAYNES® 282® were built onto a carbon steel building platform in several configurations. The samples were removed from the building platform after heat treatment and subjected to detailed composition analysis and microstructural characterization to investigate the effect of the building platform material on the properties of the additively manufactured part. Room temperature and high temperature tensile testing were used to characterize the material. Results showed no risk of large-scale chemical composition change, or mechanical property degradation of built-up material from on-platform heat treatment.

Predicting defects in laser powder bed fusion using in-situ thermal imaging data and machine learning

Variation in the local thermal history during the Laser Powder Bed Fusion (LPBF) process in Additive Manufacturing (AM) can cause micropore defects, which add to the uncertainty of the mechanical properties ( e.g. , fatigue life, tensile strength) of the built materials. In-situ sensing has been proposed for monitoring the AM process to minimize defects, but successful minimization requires establishing a quantitative relationship between the sensing data and the porosity, which is particularly challenging with a large number of variables ( e.g. , laser speed, power, scan path, powder property). Physics-based modeling can simulate such an in-situ sensing-porosity relationship, but it is computationally costly. In this work, we develop Machine Learning (ML) models that can use in-situ thermographic data to predict the micropore of LPBF stainless steel materials. This work considers two identified key features from the thermal histories: the time above the apparent melting threshold ( τ ) and the maximum radiance ( T max ). These features are computed, stored for each voxel in the built material, and then used as inputs. The binary state of each voxel, either defective or normal, is the output. Different ML models are trained and tested for the binary classification task. In addition to using the thermal features of each voxel to predict its own state, the thermal features of neighboring voxels are also included as inputs. This is shown to improve the prediction accuracy, which is consistent with thermal transport physics around each voxel contributing to its final state. Among the models trained, the F1 scores on test sets reach above 0.96 for Random Forests. Feature importance analysis based on the ML models shows that T max is more important to the voxel state than τ . The analysis also finds that the thermal history of the voxels above the present voxel is more influential than those beneath it. Our study significantly extends the capability of using in-situ thermographic data to predict porosity in LPBF materials. Since ML models are fast, they may play integral roles in the optimization and control of such AM technologies.

Methodology and experimental validation of analytical melt pool models for laser powder bed fusion

Laser Powder Bed Fusion (LPBF) is a frequently used Additive Manufacturing (AM) technique for producing metal parts with complex shapes. One of the crucial factors in obtaining an optimal part is understanding the behaviour of the melt pool, a pool of liquid metal molten by a laser. Its size and shape are the result of a wide range of (processing) parameters, making it labour intensive and costly to identify an optimal processing range. To accelerate the identification of suitable processing conditions, this work presents a novel methodology that combines (semi-) analytical expressions of the melt pool width w and the aspect ratio R=d/w to compute the depth d over a large processing range. This range includes both conduction (R<1) and keyhole (R>1) mode melting regimes. The novelty of the presented approach is the prediction of absolute melt pool dimensions for both the conduction and keyhole regime. Furthermore, this methodology is extensively validated for three common LPBF materials: Titanium Ti-6Al-4V, Stainless Steel 316L and Inconel 718. The average errors obtained between model and experimental data of the melt pool width & depth in a relevant processing range (0,8<R<3) are 10,92% & 11,37%, 12,58% & 10,99% and 15,27% & 12,81% for the three materials respectively. With these results, this work shows that the proposed methodology performs well in predicting melt pool dimensions for a large processing range, both in terms of speed and accuracy.