Selective Laser Melting Products Research Articles

Influence of Typical Technological Parameters on the Forming Quality of TA1 in Selective Laser Melting

As an emerging additive manufacturing technology with potential, selective laser melting (SLM) technology is one of the current mainstream additive manufacturing processes. Many complex conditions affect the quality of the SLM products, such as extremely short forming time, rapidly changing forming environment, and micron-level melting area. Numerical simulation and a printing experiment were used to study the influence of typical technological parameters on the forming quality of SLM products, where TA1 was used as the printing material. The typical technological parameters mainly considered laser power, laser scanning speed, hatch spacing, and laser energy density. Simulation analysis was based on the maximum temperature and the size of the molten pool, and the printing experiment was focused on the parameter design methods for typical processes and the forming quality of printed products. The results show the following: (1) An increase in laser power and laser energy density can significantly improve the forming quality. However, excessive input energy will lead to poor surface quality; (2) Scanning speed and hatch spacing need to be selected according to the size of the molten pool, which mainly influences the lap rate of the molten pool. The results of this study may provide some guidance for parameter setting and forming quality optimization in SLM manufacturing process.

Comparison of tensile properties and porcelain bond strength in metal frameworks fabricated by selective laser melting using three different Co-Cr alloy powders

Statement of problemThe selective laser melting (SLM) manufacturing technique has been widely employed to produce Co-Cr dental metal frameworks. The selection of Co-Cr alloy powders has the potential to influence the microstructure and tensile properties, consequently impacting the bond strength of the metal-porcelain. However, limited information is available regarding the effect of Co-Cr alloy powder on these properties when all other factors remain consistent. PurposeThe purpose of this in vitro study was to assess how the choice of Co-Cr alloys during SLM manufacturing influences the microstructure, tensile properties, and bond strength of metal-ceramic combinations. Material and methodsThree different Co-Cr alloy powders, Co-Cr-Mo, Co-Cr-Mo-W, and Co-Cr-W were selected in this study. The powder characteristics and chemical compositions were analyzed using a scanning electron microscope (SEM) and energy dispersive X-ray (EDX) analysis, respectively. Subsequently, 12×12×15-mm cube specimens, cylindrical tensile test specimens, and 25×3×0.5-mm metal strips were fabricated using the SLM technique. Microstructural investigations of the cube specimens were conducted after metallographic preparation using SEM. The cylindrical tensile specimens (n=8) from each composition were subjected to tensile tests at a deformation rate of 0.5 mm/min. Following the application of ceramic to the metal specimens (n=10) in each group, the strength of the metal-ceramic bond was evaluated through a 3-point bend test conducted at a crosshead speed of 1 mm/min. Mechanical properties obtained from the tensile tests and bond strength values were statistically analyzed using a one-way ANOVA and Tukey post hoc comparison tests (α=.05). ResultsMelt pool boundaries, columnar and equiaxed grains, and precipitates were observed in the microstructures of 3 different alloys produced by SLM. The Co-Cr-Mo-W alloy had more uniformly dispersed and finely distributed precipitates compared with other alloy compositions. The Co-Cr-Mo-W alloy had exhibited the highest yield strength (1068.0 ±41.2 MPa) and ultimate tensile strength (1263.4 ±10.7 MPa) while showing the lowest ductility under the tensile tests (6.1 ±0.9%) among all 3 alloys. Significant differences in the tensile mechanical properties were observed in the alloys except between the yield strength of the Co-Cr-Mo and Co-Cr-W alloys. The highest elongation (8.9 ±1.2%) was seen in the Co-Cr-Mo alloy. However, no significant differences were detected regarding the bond strength of all 3 groups (P>.05). The mean bond strength values were approximately 42 MPa for all the alloys. ConclusionsThe results indicate that the selection of different Co-Cr alloy powders used in SLM production may influence both microstructure and tensile properties. However, the strength of the metal-ceramic bond of Co-Cr alloys remained unaffected by this selection.

Selective LASER melting part quality prediction and energy consumption optimization

Selective LASER Melting (SLM) popularity is increasing because of its ability to quickly produce components with acceptable quality. The SLM process parameters, such as LASER power and scan speed, play a significant role in assuring the quality of customized SLM products. Therefore, the process parameters must be tuned appropriately to achieve high-quality customized products. Most existing methods for adjusting the SLM’s parameters use multiple inputs and one or two outputs to develop a model for achieving their desired quality. However, the number of the model’s input and output parameters to be considered can be increased to achieve a more comprehensive model. Furthermore, energy consumption is also a factor that should be considered when adjusting input parameters. This paper presents a multi-inputs-multi-outputs (MIMO) artificial neural network model to predict the SLM product qualities. We also try to combine training data from different sources to achieve a more general model that can be used in real applications by industries. The model inputs are LASER power, scan speed, overlap rate, and hatch distance. Moreover, four critical product quality measures: relative density, hardness, tensile strength, and porosity, are used as the model’s outputs. After finding a proper model, an energy optimization method is developed using the genetic algorithm in this paper. The objective of the optimization is to minimize the energy consumption of SLM manufacturing with a less compromised output quality. The results of this study can be used in the industry to decrease energy consumption while maintaining the required quality.

Dimensional Changes of Selectively Laser-Melted AlSi10Mg Alloy Induced by Heat Treatment

AlSi10Mg alloy products with a hydrogen content of approximately 3.9 or 5.6 cm3/100 g-Al of hydrogen were fabricated by selective laser melting (SLM) using normal (as-received) and moist powders, and their non-reversible dimensional changes during heat treatment at 473 or 803 K were investigated. The linear dimensional change arising from the heat treatment at 473 K was approximately 0.22% by 3.6 ks and remained constant thereafter. This behavior was independent of the amount of hydrogen in the SLM products, suggesting that the dimensional changes at 473 K were induced by precipitation of Si phase from the α-Al phase. However, the linear dimensional changes during the heat treatment at 803 K were comparatively large and continued to increase during the heat treatment. At the same time, the linear dimensional changes at 803 K also showed a dependence on the amount of hydrogen in the SLM products. These phenomena indicated that the porosity expansion and precipitation of Si phase occurred simultaneously at 803 K. For the SLM product with a hydrogen content of approximately 3.9 cm3/100 g-Al, the linear dimensional change during the heat treatment at 803 K was 0.867% at 18 ks, of which 0.116% and 0.751% were estimated to have been induced by the precipitation of Si phase and the porosity expansion, respectively. From gas analyses using different methods, it was elucidated that the hydrogen desorbed from the powder and was entrapped in the SLM products at the time of laser scanning, and then enriched to the porosities during the heat treatment at 803 K, causing the porosity expansion.

Microstructural analysis and mechanical properties of AlSi10Mg alloy components produced via SLM

Selective Laser Melting (SLM) is a manufacturing process that involves layer-by-layer fusion of metal powder material using a laser beam. AlSi10Mg alloy, a hypoeutectic aluminum-silicon alloy, is known for its favorable mechanical properties, low density, and corrosion resistance, making it widely used in various industries. While traditionally used for casting, the unique properties of AlSi10Mg alloy have opened up opportunities for additive manufacturing, including SLM technology. This paper explores the tracks quality and preferable parameter interval for production via SLM. SLM products exhibit unique microstructures with distinct advantages and limitations. This study underscores the importance of careful parameter selection during SLM and the need for effective quality control in achieving desired mechanical properties.

Investigation of the Best Manufacturing Orientation of Co-Cr-W-Si Dental Prosthetic Elements in the Selective Laser Melting Process

It is well known that Selective Laser Melting (SLM) does not provide the same mechanical properties in all directions of the part. This is due to the microstructural grain orientation and pore shape in SLM products. Therefore, depending on the direction of the pressure applied to the SLM product, a different manufacturing orientation is required to achieve the best mechanical properties. Changing the microstructural grain orientation is difficult through SLM, but a process to reduce the size and number of the pores can be discovered through different combinations of manufacturing parameters. In prosthodontics, pressure is usually applied in the vertical direction, which leads to compression and bending of crowns with bridges. The compressive load can be easily absorbed in the crowns, but the bending force has a significant effect here. Therefore, a product with high tensile strength and high ductility is needed to survive longer. Considering these requirements, this study determined the best parameters for laser processing by SLM method to reduce porosity and improve mechanical strength and ductility of Co-Cr-W-Si alloy products. The result is a relative product density of 100% for cubic specimens and a yield strength, ultimate tensile strength, and elongation at break of the tensile specimens of 900 MPa, 1200 MPa, and 15%, respectively, obtained in specimen build-up in the Z direction with a laser power of 60 W and a scanning speed of 450 mm/s. Eventually, the best orientation for the production of dental prosthetic elements using the SLM process was determined.

Dynamic compressive properties and underlying failure mechanisms of selective laser melted Ti-6Al-4V alloy under high temperature and strain rate conditions

In this study, high speed impacting tests are systematically conducted on a split Hopkinson pressure bar device to investigate the strain rate and temperature dependence of dynamic compressive properties of Ti-6Al-4 V (TC4) fabricated by selective laser melting (SLM), the ranges of strain rate and temperature are 2000–6000/s and 25–650 ℃, respectively. The results reveal that the yield strength and ultimate compressive strength of the SLM-TC4 alloy increase with the increasing strain rate and the decreasing temperature, showing obvious strain rate and temperature sensitivities. The high speed impacting load intensifies the texture of the SLM-TC4 alloy significantly. Adiabatic shear band (ASB) is more likely to evolve at higher temperatures and strain rates, submicron equiaxed grains formed in the ASB and the surrounding area are mainly ascribed to the combination of dynamic recrystallization, deformation-induced twinning and transverse α-lath splitting. Within the ASB, grains with {0001} pole orientation are rotated by approximately 45° with respect to the shear direction, indicating that the recrystallized grains are able to reorient themselves to accommodate to the shear deformation. The findings in this work provide a theoretical basis to understand the deformation behavior and mechanism of SLM-TC4 alloy under impacting loads, thus is helpful to widen the application of SLM technique and products. • SLMed TC4 alloy has significant temperature and strain rate sensitivities. • Strain hardening and thermal softening cause instable plastic deformation of SLMed TC4. • Ultrafine grains within ASBs mainly due to the deformation twinning, α -lath splitting and DRX. • Dynamic impact loading enhances the texture intensity of the deformed samples. • Recrystallized grains within ASBs can reorient themselves to accommodate to the shear deformation.

Mesoscopic-scale numerical investigation including the influence of scanning strategy on selective laser melting process

Selective laser melting (SLM) has become one of the most widely used laser additive manufacturing technologies today. However, the proper selection of scanning strategies is still a key concern for SLM production. In order to quantify the influences of different scanning strategies (One-direction, Two-directions, and Pre-sinter) on the SLM process, this paper calculated the spreading powder process based on the open-source discrete element method framework Yade, predicted the SLM mesoscopic molten pool dynamics behavior based on the open-source finite volume method framework OpenFOAM, and established the simulation flow of the SLM multi-layer multi-path forming process. The influences of different scanning strategies on grain orientation, pore defect, and surface roughness were analyzed and verified in comparison with experimental results. It is found that the grain orientation of the current formed layer under scanning strategies One-direction and Pre-sinter was almost the same as that of the previous formed layer, while the grain orientation of the current formed layer under scanning strategy Two-directions was significantly different from that of the previous formed layer. In addition, the porosity and surface roughness under scanning strategy Pre-sinter were lower than those under scanning strategies One-direction and Two-directions. This paper is expected to provide a basis for the selection of scanning strategies in practical SLM production.

A modelling framework for fatigue-life prediction of selective laser melting additive manufactured Ti-6Al-4V

Selective laser melting (SLM) enables the fabrication of complex, lightweight structural parts that would be impossible to be produced with conventional methods. Despite its advantages SLM process has some intrinsic drawbacks, with the formation of defects in parts being one of the most serious, as defects detrimentally affect the fatigue behavior of SLM parts. In order to consider defects in SLM part design and production, reliable models for defect-based fatigue life estimation models should be developed. The current work presents a modelling framework for the prediction of susceptible areas for defect formation and subsequently fatigue life estimation of SLM components. The ability of this modelling framework to effectively predict the fatigue life was tested on the prediction of fatigue life of SLM Ti-6Al-4V specimens. The small fatigue crack growth behavior of AM Ti-6Al-4V was considered. The prediction results of a fatigue life model were successfully compared with experimental data verifying the current modelling approach. Limitations concerning the prediction results are attributed mainly to the assumptions performed and the considered defect size which will be thoroughly investigated in future works.

Effect of process parameters on the microstructure and mechanical properties of AA2024 fabricated using selective laser melting

Selective laser melting (SLM) offers significant benefits, including geometric freedom and rapid production, when compared with traditional manufacturing techniques. However, the materials available for SLM production remain limited, restricting the industrial adoption of the technology. The mechanical properties and microstructure of many aluminium alloys have not been fully explored, as their manufacturability using SLM is extremely challenging. This study investigates the effect of laser power, hatch spacing and scanning speed on the mechanical and microstructural properties of as-fabricated aluminium 2024 alloy (AA2024) manufactured using SLM. The results reveal that almost crack-free structures with high relative density (99.9%) and Archimedes density (99.7%) have been achieved. It is shown that when using low energy density (ED) levels, large cracks and porosities are a major problem, owing to incomplete fusion; however, small gas pores are prevalent at high-energy densities due to the dissolved gas particles in the melt pool. An inversely proportional relationship between ED and microhardness has also been observed. Lower ED decreases the melt pool size and temperature gradients but increases the cooling rate, creating a fine-grained microstructure, which restricts dislocation movement, therefore increasing the microhardness. The highest microhardness (116 HV0.2), which was obtained from one of the lowest EDs used (100 J/mm3), is 45% higher than as-cast AA2024-0, but 17% lower than wrought AA2024-T6 alloy.

Plastic strain distribution throughout the microstructure duality during the fracture process of non-combustible Mg products fabricated by selective laser melting

In this study, several Mg-9%Al-2%Ca alloy round-bar specimens were fabricated by the selective laser melting (SLM) process. A fraction of the specimens was submitted to tensile testing. Then, the remaining fraction of specimens were drilled and subsequently submitted to further tensile testing interrupted at 90% of the ultimate tensile strength (UTS). Fracture surfaces were analyzed and an Electron Backscatter Diffraction (EBSD) analysis was performed to observe plastic strain. The results showed a dispersed plastic strain distribution that concentrated at the coarse grain microstructure, specifically at the outer regions of each melt pool formation. Microstructure coarsening is an intrinsic phenomenon of the SLM processes and induces crack arrest during the transition from a stable fracture to an unstable fracture. Accordingly, fractography results showed a large flattened area in the fracture surface, which suggests a stable and propagating plastic strain beneath the fracture surface, but no crack propagation of the corresponding length was found, despite interrupting the test at 90% of the UTS value. Based on this information, an indicator that evaluates plastic strain as continuous or discontinuous could be used in order to explain the high tensile strength and fracture behavior of SLM products in as-built conditions, which have been discussed but not verified to date.

Structure and mechanical properties of a FeCoCrNi high-entropy alloy fabricated via selective laser melting

The relative density of high-entropy alloys fabricated with selective laser melting (SLM) was enhanced via a process optimization method based on polynomial regression analysis. The resulting alloy exhibited a high relative density (99.71%) and excellent tensile properties (tensile strength = 720 MPa; post-fracture elongation = 31.85%). Optimization has been more commonly based on volumetric energy density (VED), but the unreliability of this method has been evidenced by the large difference in relative densities achieved using the VED-based approach. The high strength of alloy samples was investigated based on structural characterization, and the formation mechanisms of various defects are discussed. There is no micro-segregation or secondary phase according to both theoretical calculations and experimental observation. The strengthening mechanism of SLM FeCoCrNi sample has been reported by quantitative analysis of dislocation strengthening and fine grain strengthening. It was found that the dislocation strengthening contributed more than fine grain strengthening to the increased yield strength in SLM. This deeper insight into the processing and the strengthening mechanisms is expected to contribute to improved mechanical properties of SLM products, thereby increasing the potential for industrial applications of SLM.

Mesoscopic-Scale Numerical Simulation Including the Influence of Process Parameters on SLM Single-Layer Multi-pass Formation

Selective laser melting (SLM) is a metal additive manufacturing technology that directly forms three-dimensional complex components according to digital models via layer-by-layer addition. It has been widely used in medical personalization, aerospace, and other fields. To analyze the influence of different process parameters, such as the line energy density and hatch space on the SLM single-layer multi-pass formation process, a random particle distribution of the powder bed was first obtained via the open-source discrete element method (DEM) code Yade. The prediction model of the molten pool dynamic behavior during the SLM formation process was then established based on the “metal-gas” two-phase flow model. The conservation equation considered thermal factors, such as the Marangoni effect, the porosity in the mushy zone, and the gasification phenomenon. Laser energy was then applied by the body heat source model, which directly tracked the metal-phase surface affected by the laser in real time and applied energy to the metal-phase elements within a certain thickness. By analyzing the simulation results, it was found that to obtain a good formation zone in actual SLM production for 316L stainless steel, from the perspective of controlling line energy density, 200 J/m should be used to obtain a relatively flat solidified track and to establish a good connection with the substrate or the upper formation layer; from the perspective of controlling the hatch space, 45 μm should be used to ensure a good connection between adjacent solidified tracks, a relatively flat formation surface, and high production efficiency. These conclusions were consistent with the experimental results. This article offers a scientific rationale for parameter selection during the SLM formation process of 316L stainless steel.

Optimized hatch space selection in double-scanning track selective laser melting process

Additive manufacturing (AM) techniques such as selective laser melting (SLM) have many advantages over traditional manufacturing methods. However, the quality of SLM products is critically dependent on the process parameters, e.g., the laser power, scanning speed, powder layer thickness, hatch space, and scan length. Determining the parameter settings which optimize the product quality is a challenging, but extremely important problem for manufacturers. In a previous study, the present group determined the optimal values of the laser power and scanning speed for 316L stainless steel powder beds. The present study extends this work to investigate the effects of the hatch space and scan length on the melting pool characteristics in a double-scanning track SLM process. A three-dimensional finite element model is constructed to predict the features of the scan track melt pool for various values of the hatch space and scan length. A circle packing design method is then used to select a representative set of hatch space and scan length parameters to train artificial neural networks (ANNs) to predict the melt pool temperature, melt pool depth, and overlap rate between adjacent tracks. Finally, the trained ANNs are used to create process maps relating the scan track features to the hatch space and scan length. The optimal hatch space and scan length region of the temperature process map is then determined based on a joint consideration of the peak temperature (less than 3300 K), the difference in depth of adjacent melt pools (less than 10 μm), and the overlap rate of adjacent scan tracks (25~35%). The results indicate that the optimal hatch space is equal to 61% of the laser spot size given an SLM system with a laser power of 180 W, a scanning speed of 680 mm/s, a laser spot size of 120 μm, and a 316L SS powder layer thickness of 50 μm.

Influence of laser power and scan speed on the microstructure and properties of GH4169 alloy prepared by selective laser melting

In this work, GH4169 alloy prepared by selective laser melting (SLM) used the domestic SLM equipment, the effects of different laser power and scan speed on the density, microstructure and mechanical properties of GH4169 alloy were systematically studied. The results showed that the density and hardness of SLM products increased with the increase of laser power. When the laser power was 300 W, The microstructure of alloy was uniform, and the density and Vickers hardness of alloy were 8.19 g/cm3 and 345.6 HV, respectively. The laser transferred energy decreased with the increase of scan speed, which cause more holes and cracks in the alloy. The smaller scan speed, the larger width and smaller height of ichthyoid microstructure. When the scan speed was lower than 1400 mm/s, the L and H were about 110 μm and 50 μm respectively, and the solidified structure was uniform and dense.

X-ray CT analysis of the influence of process on defect in Ti-6Al-4V parts produced with Selective Laser Melting technology

Selective Laser Melting (SLM) technology is a potential Additive Manufacturing (AM) process. It has the ability to manufacture metal parts with complex construction. However, there are always defects in SLM products due to the raw materials, manufacturing parameters, and post-treatment. To investigate the relationship between manufacturing process parameters and defects in SLM products, laser power and scan speed are selected as variable parameters to fabricate cube samples. The 3D information of each specimen are collected by X-ray computed tomography, including the size, morphology, and spatial distribution of defects. The mathematical model of laser power and scanning speed with defect volume fraction was established. The result shows that when the scanning speed is less than 1200 mm/s, the defect volume rate increases slowly, but when the scanning speed is faster than 1200 mm/s, the volume rate of defects increases rapidly. As the laser power increases, the volume rate of defect decreased initially and then followed by an increase. It can be concluded that there are many defects in the part manufactured by low laser power and high scanning speed parameter, and the same result by high laser power and high scanning speed parameter. Additionally, the defects are larger and some of them distribute along the scanning path in the latter. Besides, the process window for SLM Ti-6Al-4V is created for exposing the relationship between process parameters and defects, and volume-spherical scatters are used to characterize different process zones.

Surface quality improvement by parameters analysis, optimization and heat treatment of AlSi10Mg parts manufactured by SLM additive manufacturing

The quality and reliability of selective laser melting (SLM) built components is very important. Surface quality is key quality characteristic, and it is an emergent topic for SLM products. In this paper, the influence of processing parameters such as laser power, scanning speed, overlap rate, and hatch distance of an SLM system during the fabrication of AlSi10Mg alloy parts are investigated for surface quality. The purpose of the present paper is to analyze surface quality and optimize the process parameters for quality improvement of AlSi10Mg components developed by SLM process. The effect of laser power, scanning speed, overlap rate, and hatch distance on the front face and side face surface roughness examined in as-built (AB), solution heat treatment (SHT), and artificial aging (AA). The effect of laser power on surface quality explored empirically, and ANOVA is applied to determine the best level of laser power for minimum surface roughness, standard deviation, and fluctuations. The regression analysis is performed to develop a mathematical model and used it for the optimization of processing parameters; scan speed, overlap rate, and hatch distance for achieving minimum surface roughness. Conclusively, the process parameters 0.32 kW laser power, 0.60 m/s scan speed, 35% overlap rate and 88.7 μm hatch distance determined as optimized parameters for best surface quality in as-built condition. Furthermore, the results revealed that the average surface roughness decreased by 17% after solution heat treatment.

Dimenzijske napake na izdelkih, izdelanih s selektivnim laserskim taljenjem, glede na različne orientacije in procesne parametre

Dimenzijske napake na izdelkih, izdelanih s selektivnim laserskim taljenjem, glede na različne orientacije in procesne parametre

The Influence of Selective Laser Melting Process Parameters on the Property of TiAlN/TiN Multilayer Coating on the 316L Steel

Selective laser melting (SLM) is an important advanced additive manufacturing technology. The existing SLM products cannot fully meet the requirements of high-precision and strength of the mechanical component because of their defects. The TiAlN/TiN multilayer coating can improve the surface property of SLM products. The present work aims to explore the influences of different process parameters of SLM on the property of TiAlN/TiN multilayer coating plating on the 361L specimen and the mechanism of these influences. Taking laser power, scanning speed, and scanning space as factors, an orthogonal experiment was designed. The TiAlN/TiN multilayer coating specimens can be obtained by plating on the 361L specimen, fabricated by the process parameters of SLM on the orthogonal experiment. The surface topographies and properties of TiAlN/TiN multilayer coating were tested, the influences of SLM process parameters on TiAlN/TiN multilayer coating were analyzed, and the optimal process parameter was obtained. The electron microscope images revealed that the surface morphology of TiAlN/TiN multilayer coating plating on the SLM specimen was relatively flat, and there were some macro-particles in different sizes and pin holes dispersed on it. The thickness of the TiAlN/TiN multilayer coating was 2.77–3.29 μm. The microhardness value of coating SLM specimen was more than four times that of the uncoated SLM specimen and the wear rates of the uncoated specimen were 2–4 times that of the corresponding coating specimen. The comprehensive analysis shows that the laser power had the greatest influence on the comprehensive property of the coating. The primary cause of the influence of SLM process parameters on the properties of the TiAlN/TiN multilayer coating was preliminarily discussed. When the laser power was 170 W, the scanning speed was 1,100 mm/s, and the scanning space was 0.08mm, the TiAlN/TiN multilayer coating plating on the SLM specimen had the best comprehensive property.

Effect of laser remelting on deposition quality, residual stress, microstructure, and mechanical property of selective laser melting processed Ti-5Al-2.5Sn alloy

Laser remelting (LR) is often used during selective laser melting (SLM) processes to improve the densification degree and top surface quality of the products. However, researches regarding its effects on side surface quality, residual stress, microstructure, and mechanical property are still quite lacking. The influence of the repeated usage of LR on a solidified layer is also not very clear. To address these issues, LR treatments with the cyclic numbers of 1–3 on every solidified layer have been employed during the SLM processes of a Ti-5Al-2.5Sn alloy in this study and their influences on deposition quality, residual stress, microstructure, and mechanical property were researched. The results first indicated that although the improvement in top surface quality and densification degree would be more and more notable with the increase of LR cycles, the side surface quality could not be improved through all the LR treatments. Then, it was shown by the hole-drilling tests on the surface centers of several 15 × 15 × 3 mm3 thin-plate specimens that when 1 cycle of LR was conducted on every solidified layer, the principal residual stress at the hole bottom of the SLM sample could be far beyond that of the non-treated one. In contrast, when 2 or 3 cycles of LR were conducted, the measured principal residual stresses could be reduced to lower than that of the non-treated ones. It was also proved that unlike the non-treated sample which presented a martensite-dominated microstructure with a very weak texture, all the LR-treated samples exhibited two kinds of preferential orientations. Finally, tensile properties of the stress-relieved samples were tested and it was seen that under the combined influence of the densification and the microstructure factors, the elongations of the LR-treated samples became slightly higher than that of the non-treated one whereas the tensile strengths were nearly identical. In summary, this paper demonstrates that there is still limitation in using LR as an auxiliary process of the SLM production of titanium products. The possible increase in residual stress and the formation of strong textures should be particularly considered.