Laser Processing of Metallic Materials

Journal Name	Impact Factor	CiteScore	Launched Year	First Decision (median)	APC
Coatings coatings	2.9	5.0	2011	13.7 Days	CHF 2600	Submit
Journal of Manufacturing and Materials Processing jmmp	3.3	5.1	2017	14.7 Days	CHF 1800	Submit
Materials materials	3.1	5.8	2008	15.5 Days	CHF 2600	Submit
Metals metals	2.6	4.9	2011	16.5 Days	CHF 2600	Submit
Nanomaterials nanomaterials	4.4	8.5	2010	13.8 Days	CHF 2900	Submit

15 pages, 2938 KiB

Open AccessArticle

Micromechanical and Tribological Performance of Laser-Cladded Equiatomic FeNiCr Coatings Reinforced with TiC and NbC Particles

by Artem Okulov, Olga Iusupova, Kun Liu, Jie Li, Alexander Stepchenkov, Vladimir Zavalishin, Yulia Korkh, Tatyana Kuznetsova, Krishna Kishore Mugada and Arivarasu Moganraj

Materials 2024, 17(19), 4686; https://doi.org/10.3390/ma17194686 - 24 Sep 2024

Cited by 1 | Viewed by 908

Abstract

This paper discusses a comparative micromechanical and tribological analysis of laser-cladded equiatomic FeNiCr coatings reinforced with TiC and NbC particles. Two types of coatings, FeNiCr-TiC (3 wt.% TiC) and FeNiCr-NbC (3 wt.% NbC), were deposited onto an AISI 1040 steel substrate by means [...] Read more.

This paper discusses a comparative micromechanical and tribological analysis of laser-cladded equiatomic FeNiCr coatings reinforced with TiC and NbC particles. Two types of coatings, FeNiCr-TiC (3 wt.% TiC) and FeNiCr-NbC (3 wt.% NbC), were deposited onto an AISI 1040 steel substrate by means of short-pulsed laser cladding. The chemical composition, microstructure, and micromechanical and tribological characteristics of the coatings were systematically investigated via optical and scanning electron microscopy, Raman spectroscopy, and mechanical and tribological tests. The average thicknesses and compositional transition zones of the coatings were 600 ± 20 μm and 150 ± 20 μm, respectively. Raman spectroscopy revealed that both coatings are primarily composed of a single FCC γ-phase (γ-FeNiCr). The FeNiCr + 3 wt.% TiC coating exhibited an additional TiC phase dispersed within the γ-FeNiCr matrix. In contrast, the FeNiCr + 3 wt.% NbC coating displayed a more homogeneous distribution of finely dispersed NbC phase throughout the composite, leading to enhanced mechanical behavior. Micromechanical characterization showed that the FeNiCr + 3 wt.% NbC coating possessed higher average microhardness (3.8 GPa) and elastic modulus (180 GPa) compared to the FeNiCr + 3 wt.% TiC coating, which had values of ~3.2 GPa and ~156 GPa, respectively. Both coatings significantly exceeded the AISI 1040 steel substrate in tribological performance. The FeNiCr + 3 wt.% TiC and FeNiCr + 3 wt.% NbC coatings exhibited substantial reductions in both weight loss (37% and 41%, respectively) and wear rate (33% and 42%, respectively) compared to the substrate material. These findings indicate that more finely dispersed NbC particles are better suited for hardening laser-cladded equiatomic FeNiCr-NbC coatings, making them advanced candidates for industrial applications. Full article

(This article belongs to the Topic Laser Processing of Metallic Materials)

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15 pages, 7259 KiB

Open AccessArticle

The Effect of Optimized Substrate Orientation on Layer Step in Laser Metal Deposition of Single-Crystal Nickel-Base Superalloys

by Jiachen Guo, Junxiang Zhou, Yong Sun, Bo Feng, Yunwei Zhang and Chang Ding

Materials 2024, 17(18), 4607; https://doi.org/10.3390/ma17184607 - 20 Sep 2024

Viewed by 594

Abstract

Laser metal deposition is a promising way to repair the surface defects of single-crystal components in turbo engines. Understanding the mechanisms and improving the efficiency of the repair have been long-standing problems. In this study, the influence of the substrate orientation on the [...] Read more.

Laser metal deposition is a promising way to repair the surface defects of single-crystal components in turbo engines. Understanding the mechanisms and improving the efficiency of the repair have been long-standing problems. In this study, the influence of the substrate orientation on the laser metal deposition (LMD) was investigated and its effect on repair layer-step was examined. LMD experiments were conducted on single crystal superalloys with a normal substrate orientation (001)/[100] and with an optimized substrate orientation (101)/[10

\bar{1}

]. It reveals that the laser cladding with the optimized orientation leads to a larger height of the [001] dendrite region than that with the normal orientation. The calculated results of the growth velocity, thermal gradient, and susceptibility to CET in the dendrite-preferred growth direction indicate that, for the (101)/[10

\bar{1}

] orientation, the [001]/[100] boundary is located at relative high position in each layer, which not only decreases the formation ability of stray grain significantly, but also eliminates the appearance of the maximum susceptibility. This makes the necessary dilution position much higher, and thus, a large cladding step can be selected. Our findings could find potential applications in laser repair of single-crystal components. Full article

(This article belongs to the Topic Laser Processing of Metallic Materials)

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21 pages, 10988 KiB

Open AccessArticle

Study on Laser Transmission Welding Technology of TC4 Titanium Alloy and High-Borosilicate Glass

by Changjun Chen, Lei Li, Min Zhang, Mengxuan Xu and Wei Zhang

Materials 2024, 17(17), 4371; https://doi.org/10.3390/ma17174371 - 4 Sep 2024

Cited by 1 | Viewed by 670

Abstract

As the demand for high-performance dissimilar material joining continues to increase in fields such as aerospace, biomedical engineering, and electronics, the welding technology of dissimilar materials has become a focus of research. However, due to the differences in material properties, particularly in the [...] Read more.

As the demand for high-performance dissimilar material joining continues to increase in fields such as aerospace, biomedical engineering, and electronics, the welding technology of dissimilar materials has become a focus of research. However, due to the differences in material properties, particularly in the welding between metals and non-metals, numerous challenges arise. The formation and quality of the weld seam are strongly influenced by laser process parameters. In this study, successful welding of high-borosilicate glass to a TC4 titanium alloy, which was treated with high-temperature oxidation, was achieved using a millisecond pulsed laser. A series of process parameter comparison experiments were designed, and the laser welding behavior of the titanium alloy and glass under different process parameters was investigated using scanning electron microscopy (SEM) and a universal testing machine as the primary analysis and testing equipment. The results revealed that changes in process parameters significantly affect the energy input and accumulation during the welding process. The maximum joint strength of 60.67 N was obtained at a laser power of 180 W, a welding speed of 3 mm/s, a defocus distance of 0 mm, and a frequency of 10 Hz. Under the action of the laser, the two materials mixed and penetrated into the molten pool, thus achieving a connection. A phase, Ti₅Si₃, was detected at the fracture site, indicating that both mechanical bonding and chemical bonding reactions occurred between the high-borosilicate glass and the TC4 titanium alloy during the laser welding process. Full article

(This article belongs to the Topic Laser Processing of Metallic Materials)

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14 pages, 6852 KiB

Open AccessArticle

Wear Characteristics of Textured Floating Oil Seal Surfaces: A Simulation and Experimental Study

by Hailin Zhao, Guilin Li, Zhaoyang Zhai, Jialin Yang, Dongya Zhang and Yanchao Zhang

Coatings 2024, 14(9), 1087; https://doi.org/10.3390/coatings14091087 - 24 Aug 2024

Viewed by 719

Abstract

This study aimed to analyze the effects of surface texture on the wear amount of floating oil seals and how these effects are related to the texture parameters. To achieve this, a finite element model was constructed to simulate the frictional behavior of [...] Read more.

This study aimed to analyze the effects of surface texture on the wear amount of floating oil seals and how these effects are related to the texture parameters. To achieve this, a finite element model was constructed to simulate the frictional behavior of seal discs under both textured and non-textured conditions. The study focused on a specific set of texture parameters. The texture depth was held constant, while the area density and diameter of the textures were varied. Three different area densities were considered: 10%, 20%, and 30%. Similarly, three different texture diameters were included in the study: 100, 200, and 300 μm. For each combination of area density and diameter, three different texture depths were evaluated: 50, 100, and 150 μm. The results show that compared with the non-texture, the wear loss of the texture is significantly reduced, and the wear loss is reduced by 56.8%. As the texture depth increases, the corresponding increase in wear remains relatively small. In contrast, increasing the texture diameter and area density leads to a more significant increase in wear, indicating that these two parameters have a more significant effect on the wear behavior of the seal. Under the condition of dry friction, the average friction coefficient analysis shows that the texture area density is 30%, the texture diameter is 200 μm, and the minimum value is about 0.602. Under the lubrication condition, the lowest average friction coefficient is about 0.147, the texture area density is 20%, and the texture diameter is 300 μm. Full article

(This article belongs to the Topic Laser Processing of Metallic Materials)

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20 pages, 4112 KiB

Open AccessArticle

Using Femtosecond Laser Pulses to Explore the Nonlinear Optical Properties of Ag/Au Alloy Nanoparticles Synthesized by Pulsed Laser Ablation in a Liquid

by Yasmin Abd El-Salam, Hussein Dhahi Adday, Fatma Abdel Samad, Hamza Qayyum and Tarek Mohamed

Nanomaterials 2024, 14(15), 1290; https://doi.org/10.3390/nano14151290 - 31 Jul 2024

Cited by 1 | Viewed by 1430

Abstract

Metallic nanoparticles have gained attention in technological fields, particularly photonics. The creation of silver/gold (Ag/Au) alloy NPs upon laser exposure of an assembly of these NPs was described. First, using the Nd: YAG pulsed laser ablation’s second harmonic at the same average power [...] Read more.

Metallic nanoparticles have gained attention in technological fields, particularly photonics. The creation of silver/gold (Ag/Au) alloy NPs upon laser exposure of an assembly of these NPs was described. First, using the Nd: YAG pulsed laser ablation’s second harmonic at the same average power and exposure time, Ag and Au NPs in distilled water were created individually. Next, the assembly of Ag and Au NP colloids was exposed again to the pulsed laser, and the effects were examined at different average powers and exposure times. Furthermore, Ag/Au alloy nanoparticles were synthesized with by raising the average power and exposure time. The absorption spectrum, average size, and shape of alloy NPs were obtained by using an ultraviolet-visible (UV–Vis) spectrophotometer and transmission electron microscope instrument. Ag/Au alloy NPs have been obtained in the limit of quantum dots (<10 nm). The optical band gap energies of the Ag/Au alloy colloidal solutions were assessed for different Ag/Au alloy NP concentrations and NP sizes as a function of the exposure time and average power. The experimental data showed a trend toward an increasing bandgap with decreasing nanoparticle size. The nonlinear optical characteristics of Ag/Au NPs were evaluated and measured by the Z-scan technique using high repetition rate (80 MHz), femtosecond (100 fs), and near-infrared (NIR) (750–850 nm) laser pulses. In open aperture (OA) Z-scan measurements, Ag, Au, and Ag/AuNPs present reverse saturation absorption (RSA) behavior, indicating a positive nonlinear absorption (NLA) coefficient. In the close-aperture (CA) measurements, the nonlinear refractive (NLR) indices (n₂) of the Ag, Au, and Ag/Au NP samples were ascribed to the self-defocusing effect, indicating an effective negative nonlinearity for the nanoparticles. The NLA and NLR characteristics of the Ag/Au NPs colloids were found to be influenced by the incident power and excitation wavelength. The optical limiting (OL) effects of the Ag/Au alloy solution at various excitation wavelengths were studied. The OL effect of alloy NPs is greater than that of monometallic NPs. The Ag/Au bimetallic nanoparticles were found to be more suitable for optical-limiting applications. Full article

(This article belongs to the Topic Laser Processing of Metallic Materials)

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16 pages, 5840 KiB

Open AccessArticle

Effect of Printing Orientation on the Mechanical Properties of 3D-Printed Cu–10Sn Alloys by Laser Powder Bed Fusion Technology

by Peng Yang, Dingyong He, Xingye Guo, Sheng Lu, Shujin Chen, Fanmin Shang, Dubovyy Oleksandr and Liangyu Chen

Metals 2024, 14(6), 660; https://doi.org/10.3390/met14060660 - 1 Jun 2024

Cited by 2 | Viewed by 3670

Abstract

This article focuses on investigating the effect of printing direction on the mechanical properties of Cu–10Sn alloys prepared by laser powder bed fusion (LPBF) technology. Specimens with different forming angles (0°, 15°, 30°, 45°, 60°, 75°, and 90°) were fabricated using LPBF technology, [...] Read more.

This article focuses on investigating the effect of printing direction on the mechanical properties of Cu–10Sn alloys prepared by laser powder bed fusion (LPBF) technology. Specimens with different forming angles (0°, 15°, 30°, 45°, 60°, 75°, and 90°) were fabricated using LPBF technology, and their mechanical properties were systematically tested. During the testing process, we used an Instron 5985 electronic universal material testing machine to accurately evaluate the mechanical properties of the material at a constant strain rate of 10⁻³/s. The experimental results showed that the mechanical properties of the specimens were the best when the test direction was perpendicular to the growth direction (i.e., the 0° direction). As the angle between the test direction and the growth direction increased, the mechanical properties of the material exhibited a trend of first decreasing, then increasing, and then decreasing again, which was consistent with the direction of the microtexture of the specimens. The root cause of this trend lies in the significant change in the stress direction borne by the columnar crystals under different load directions. Specifically, as the load direction gradually transitions from being parallel to the columnar crystals to perpendicular to them, the stress direction of the columnar crystals also shifts from the radial direction to the axial direction. Due to the differences in the number and strength of grain boundaries in different stress directions, this directly leads to changes in mechanical properties. In particular, when the specimen is loaded in the radial direction of the columnar crystals, the grain boundary density is higher, and these grain boundaries provide greater resistance during dislocation migration, thus significantly hindering tensile deformation and enabling the material to exhibit superior tensile properties. Among all the tested angles, the laser powder bed fusion specimen with a forming angle of 0° exhibited the best mechanical properties, with a tensile strength of 723 MPa, a yield strength of 386 MPa, and an elongation of 33%. In contrast, the specimen with a forming angle of 90° performed the worst in terms of tensile properties. These findings provide important insights for us to deeply understand the mechanical properties of Cu–10Sn alloys prepared by LPBF. Full article

(This article belongs to the Topic Laser Processing of Metallic Materials)

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26 pages, 7016 KiB

Open AccessArticle

Structural and Morphological Studies of Pt in the As-Grown and Encapsulated States and Dependency on Film Thickness

by Berkin Nergis, Sondes Bauer, Xiaowei Jin, Lukas Horak, Reinhard Schneider, Vaclav Holy, Klaus Seemann, Sven Ulrich and Tilo Baumbach

Nanomaterials 2024, 14(8), 725; https://doi.org/10.3390/nano14080725 - 20 Apr 2024

Cited by 1 | Viewed by 1338

Abstract

The morphology and crystal structure of Pt films grown by pulsed laser deposition (PLD) on yttria-stabilized zirconia (YSZ)at high temperatures Tg = 900 °C was studied for four different film thicknesses varying between 10 and 70 nm. During the subsequent growth of the [...] Read more.

The morphology and crystal structure of Pt films grown by pulsed laser deposition (PLD) on yttria-stabilized zirconia (YSZ)at high temperatures Tg = 900 °C was studied for four different film thicknesses varying between 10 and 70 nm. During the subsequent growth of the capping layer, the thermal stability of the Pt was strongly influenced by the Pt film’s thickness. Furthermore, these later affected the film morphology, the crystal structure and hillocks size, and distribution during subsequent growth at Tg = 900 °C for a long duration. The modifications in the morphology as well as in the structure of the Pt film without a capping layer, named also as the as-grown and encapsulated layers in the bilayer system, were examined by a combination of microscopic and scattering methods. The increase in the thickness of the deposited Pt film brought three competitive phenomena into occurrence, such as 3D–2D morphological transition, dewetting, and hillock formation. The degree of coverage, film continuity, and the crystal quality of the Pt film were significantly improved by increasing the deposition time. An optimum Pt film thickness of 70 nm was found to be suitable for obtaining a hillock-free Pt bottom electrode which also withstood the dewetting phenomena revealed during the subsequent growth of capping layers. This achievement is crucial for the deposition of functional bottom electrodes in ferroelectric and multiferroic heterostructure systems. Full article

(This article belongs to the Topic Laser Processing of Metallic Materials)

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14 pages, 28826 KiB

Open AccessArticle

Laser Remelting of Ductile Cast Iron to Achieve a Graphite-Free Surface Layer for Enabling a Manual High-Gloss Finish

by Laura Kreinest, Johannes Schüssler, Onur Özaydin, Sujith Kochuthundil Subhash, Edgar Willenborg and Andreas Bührig-Polaczek

Metals 2024, 14(3), 347; https://doi.org/10.3390/met14030347 - 18 Mar 2024

Viewed by 1313

Abstract

Laser remelting is being explored as a viable technique for obtaining a graphite-free, defect-free surface layer on cast iron EN GJS 400-15. The goal is to obtain a large remelted layer along with a low surface roughness to enable a subsequent manual high-gloss [...] Read more.

Laser remelting is being explored as a viable technique for obtaining a graphite-free, defect-free surface layer on cast iron EN GJS 400-15. The goal is to obtain a large remelted layer along with a low surface roughness to enable a subsequent manual high-gloss surface finish. The impact of the laser remelting process parameters is evaluated by using samples with three different cooling rates, resulting in different graphite microstructures. By utilizing four passes and a laser power of 300 W, the smallest roughness and largest remelting depth are achieved. The remelted layer is mostly devoid of graphite particles. Subsequent manual polishing is performed to evaluate the potential for achieving a high-gloss finish with a roughness of Sa < 0.05 µm. Laser remelting alone does not improve visual appearance or reduce roughness. However, after manual polishing, the roughness of the laser-remelted surfaces with Sa = 0.018 µm is one order of magnitude smaller than the manually polished initial state. Graphite removal during laser remelting therefore makes it possible to achieve a conventional and high-gloss polish, overcoming the previous limitations of GJS materials. Full article

(This article belongs to the Topic Laser Processing of Metallic Materials)

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11 pages, 5490 KiB

Open AccessArticle

Synthesis of Nickel-Based Nanoparticles by Pulsed Laser Ablation in Liquids: Correlations between Laser Beam Power, Size Distribution and Cavitation Bubble Lifetime

by Atikur Rahman and Grégory Guisbiers

Metals 2024, 14(2), 224; https://doi.org/10.3390/met14020224 - 12 Feb 2024

Cited by 1 | Viewed by 2531

Abstract

Pulsed laser ablation in liquids (PLAL) is a colloidal synthesis technique attracting significant interest from the scientific community due to the quality of the nanoparticles being produced. In this type of synthesis protocol, the cavitation bubble plays a vital role during the synthesis [...] Read more.

Pulsed laser ablation in liquids (PLAL) is a colloidal synthesis technique attracting significant interest from the scientific community due to the quality of the nanoparticles being produced. In this type of synthesis protocol, the cavitation bubble plays a vital role during the synthesis of nanoparticles. This work studied the effect of the laser beam power on cavitation bubble lifetime. Three different laser beam power values (5.8 W, 7.5 W and 10.5 W) were used to irradiate a pure nickel target in de-ionized (DI) water to synthesize nickel-based nanoparticles. The optimal repetition rate maximizing the production of nanoparticles was determined by atomic emission spectroscopy for each laser beam power. It was determined that the optimal repetition rate increased exponentially with laser beam power, while the cavitation bubble lifetime decreased logarithmically with the laser beam power. Moreover, the effect of the laser beam power on the cavitation bubble lifetime also had an effect on the size distribution of the nanoparticles being produced; the smallest size distribution was obtained at the highest laser beam power. Full article

(This article belongs to the Topic Laser Processing of Metallic Materials)

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19 pages, 9884 KiB

Open AccessArticle

Improving Commercial Motor Bike Rim Disc Hardness Using a Continuous-Wave Infrared Fibre Laser

by Juan Ignacio Ahuir-Torres, Andre D. L. Batako, Nugzar Khidasheli, Nana Bakradze and Guanyu Zhu

J. Manuf. Mater. Process. 2024, 8(1), 18; https://doi.org/10.3390/jmmp8010018 - 24 Jan 2024

Viewed by 1827

Abstract

This study is focused on examining the feasibility of applying laser hardening to a commercial metallic bike rim, employing a CW IR fibre laser. The research comprises two main phases. The first phase involves an assessment of the impact of laser parameters on [...] Read more.

This study is focused on examining the feasibility of applying laser hardening to a commercial metallic bike rim, employing a CW IR fibre laser. The research comprises two main phases. The first phase involves an assessment of the impact of laser parameters on the metallic microstructure, while the second phase involves the actual laser hardening of the bike rim. A comprehensive evaluation encompassing hardness measurements, optical microscopy, and scanning electron microscopy was conducted on the samples. The microstructure type can be manipulated by skilfully adjusting the laser parameters, allowing for the creation of various microstructure variants within the laser-hardened zone for specific laser conditions. In this regard, multiple microstructure types were observed. The hardness of the laser-processed zones exhibited variations corresponding to the specific microstructure. Notably, the molten zone (MZ) and the second heat-affected zone (HAZ II) exhibited the highest levels of hardness. Furthermore, it was observed that a scan overlap of ≥ 75% led to an augmentation in hardness. This study sheds light on the intricate interplay between laser parameters, microstructure, and resultant hardness in the context of laser hardening of metallic materials. Full article

(This article belongs to the Topic Laser Processing of Metallic Materials)

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17 pages, 4820 KiB

Open AccessArticle

Exploring the Effects of Laser Surface Modification on AISI 301LN Steel: A Micro-Mechanical Study

by Mohammad Rezayat, Antonio Mateo and Joan Josep Roa

J. Manuf. Mater. Process. 2023, 7(6), 191; https://doi.org/10.3390/jmmp7060191 - 26 Oct 2023

Cited by 4 | Viewed by 2171

Abstract

This article investigates the surface hardening capability of a metastable austenitic TRansformation Induced Plasticity (TRIP) stainless steel, particularly on AISI 301LN, by laser texturing. This technology produces microstructural surface changes in terms of both phase transformation and grain size modification and, as a [...] Read more.

This article investigates the surface hardening capability of a metastable austenitic TRansformation Induced Plasticity (TRIP) stainless steel, particularly on AISI 301LN, by laser texturing. This technology produces microstructural surface changes in terms of both phase transformation and grain size modification and, as a direct consequence, the laser influences the surface characteristics, mainly hardness and roughness. In this sense, the key parameters (laser power, scanning speed and position of the focal length) were investigated by using a Design of Experiments (DoE) in detail to better understand the correlation between texturing parameters, microstructural and mechanical changes, always at the superficial level. From all the aforementioned information, the results show that the maximum surface hardening is obtained by increasing the laser power and decreasing the scanning speed. Furthermore, by reducing the focal distance, the depth of the microstructural evolution layer is more significant, while the width is less affected. Finally, a suitable model was developed to correlate the processing parameters here investigated with the resulting surface integrity, in terms of mechanical properties, by means of a regression equation. Full article

(This article belongs to the Topic Laser Processing of Metallic Materials)

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14 pages, 12173 KiB

Open AccessArticle

Surface Properties and Cavitation Erosion Resistance of Cast Iron Subjected to Laser Cavitation Treatment

by Chunhui Luo and Jiayang Gu

Metals 2023, 13(10), 1793; https://doi.org/10.3390/met13101793 - 23 Oct 2023

Cited by 1 | Viewed by 1285

Abstract

Laser cavitation is a novel surface modification technology using the impact of bubble collapse and laser-induced plasma to induce plastic deformation and produce compressive residual stress on material surfaces. The effects of laser cavitation on surface properties and the cavitation erosion resistance of [...] Read more.

Laser cavitation is a novel surface modification technology using the impact of bubble collapse and laser-induced plasma to induce plastic deformation and produce compressive residual stress on material surfaces. The effects of laser cavitation on surface properties and the cavitation erosion resistance of cast iron were studied. In this work, three-dimensional morphology and residual stress distribution of the laser cavitation area under different laser parameters was obtained, the variation regularities of the topographic range and impact depth of the affected area was discussed, and the weight loss rate of cast iron under different defocusing amounts was studied. It was found that laser cavitation can effectively improve the anti-cavitation erosion property of the cast iron surface, and the optimal value was reached when the defocusing amount was H = 1 mm. Combined with the various defocusing amounts and the variation trend of the weight loss rate of cavitation erosion, the cavitation erosion time corresponding to each stage of the cast iron (incubation, rise, decay, and stability) was obtained. Full article

(This article belongs to the Topic Laser Processing of Metallic Materials)

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14 pages, 5776 KiB

Open AccessArticle

Fracture Toughness of Ti6Al4V/Cp-Ti Multi-Material Produced via Selective Laser Melting

by Arseniy Repnin, Evgenii Borisov, Anton Emelianov and Anatoliy Popovich

Metals 2023, 13(10), 1738; https://doi.org/10.3390/met13101738 - 13 Oct 2023

Cited by 3 | Viewed by 1528

Abstract

Multi-materials can locally enhance the properties of products to improve their performance. In some cases, it might be necessary to improve the fracture toughness properties locally. This work is devoted to investigating the fracture toughness of multi-material Ti6Al4V/Cp-Ti specimens produced via laser powder [...] Read more.

Multi-materials can locally enhance the properties of products to improve their performance. In some cases, it might be necessary to improve the fracture toughness properties locally. This work is devoted to investigating the fracture toughness of multi-material Ti6Al4V/Cp-Ti specimens produced via laser powder bed fusion (L-PBF). The powder feeding and distributing system of the L-PBF machine was modified for programmable dual-powder feed capability. The multi-material Ti6Al4V/Cp-Ti samples analyzed in this work are layered materials, where the Ti6Al4V alloy serves as the base material and Cp-Ti is present as separate layers. Samples of this type rely on the principle of crack inhibition, where fracture energy is dissipated in the more ductile Cp-Ti layers. Two variants of alternating ductile layers were studied. The microstructure of the materials and interfacial zone were analyzed using an optical microscope. Chemical composition was examined with a scanning electron microscope. The size of the interfacial zone in the multi-material averaged between 250 and 300 μm. A comparison of the tensile tests results with the literature data (of relatively pure Ti6Al4V alloy) reveals that there is a minor reduction in ultimate tensile strength and elongation. The obtained results confirm the possibility of locally increasing fracture toughness through the creation of a multi-material structure using L-PBF. Full article

(This article belongs to the Topic Laser Processing of Metallic Materials)

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18 pages, 15462 KiB

Open AccessArticle

Effect of Electrically Assisted Preheating on Microstructure and Properties of Laser-Cladded Co-Based Coating on CP-Ti Alloy Substrate

by Xiao Li, Jiahui Peng, Fei Wang, Zengzhi Liu and Xinyi Feng

Coatings 2023, 13(8), 1379; https://doi.org/10.3390/coatings13081379 - 6 Aug 2023

Cited by 2 | Viewed by 1742

Abstract

Co-based coatings were prepared on commercially pure titanium (CP-Ti) with electrically assisted pre-heating (EAPH), followed by laser cladding with the assistance of pulsed current. Conventional pre-heating (CPH) laser cladding was carried out as a control to investigate the effects of a pulsed current [...] Read more.

Co-based coatings were prepared on commercially pure titanium (CP-Ti) with electrically assisted pre-heating (EAPH), followed by laser cladding with the assistance of pulsed current. Conventional pre-heating (CPH) laser cladding was carried out as a control to investigate the effects of a pulsed current on the phase composition, microstructure, microhardness, and wear resistance of the coatings. The results showed that periodically varied pulsed currents generate an induced magnetic field. This field fragments bottom dendrites and transforms columnar dendrites into equiaxed crystals through the influence of the Lorentz force. The phase composition of the coatings remained unchanged under the pulsed current, as well as unassisted and CPH condition, consisting of γ-Co, α-Ti, CoTi₂ solid solution, and TiC, Cr₇C₃ hard phases. The microhardness of the coating increased at 720 A due to grain refinement, compared to unassisted and preheated coatings at the same temperature. Moreover, a suitable preheating temperature can reduce crack generation and improve the wear properties of the coating. Full article

(This article belongs to the Topic Laser Processing of Metallic Materials)

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15 pages, 9017 KiB

Open AccessArticle

Dry Friction Properties of Friction Subsets and Angle Related to Surface Texture of Cemented Carbide by Femtosecond Laser Surface Texturing

by Hang Cheng, Fang Zhou and Zihao Fei

Coatings 2023, 13(4), 741; https://doi.org/10.3390/coatings13040741 - 5 Apr 2023

Cited by 4 | Viewed by 1728

Abstract

This paper investigated the use of laser surface texturing (LST) to improve the tribological properties of YG6X cemented carbide. Three different spaced groove textures were processed on the surface of the YG6X carbide samples using a femtosecond laser. Friction experiments and friction simulations [...] Read more.

This paper investigated the use of laser surface texturing (LST) to improve the tribological properties of YG6X cemented carbide. Three different spaced groove textures were processed on the surface of the YG6X carbide samples using a femtosecond laser. Friction experiments and friction simulations were performed under two friction subsets and two friction directions. The testing results showed that when the area density was 46%, the texture surface was beneficial when sliding against Si₃N₄, but not beneficial in reducing the coefficient of friction when sliding against Ti6Al4V titanium alloy. At area densities of 23% and 15.3%, the texture surface was beneficial when sliding against Si₃N₄, but not beneficial when sliding against the Ti6Al4V titanium alloy. When selecting the friction direction at 45° to the area density of 15.3%, the texture surface was not beneficial when sliding against the Si₃N₄ and Ti6Al4V titanium alloy. Sliding with Si₃N₄, the higher the stress value, the more easily the material was destroyed, leading to an elevated coefficient of friction and wear area. Sliding with Ti6Al4V titanium alloy, the higher the stress value of Ti6Al4V titanium alloy, the more easily the Ti6Al4V titanium alloy wore and generated a large number of abrasive chips. Full article

(This article belongs to the Topic Laser Processing of Metallic Materials)

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8 pages, 2644 KiB

Open AccessCommunication

Laser-Induced Iridescent Steel Surfaces with Moderate Reflectance

by Xuyang Wang, Zhongjia Huang and Xinying Shi

Metals 2023, 13(3), 545; https://doi.org/10.3390/met13030545 - 8 Mar 2023

Cited by 1 | Viewed by 1752

Abstract

Laser-induced coloration on metallic surfaces has emerged as a clean technology to prepare visual designs. After laser processing, the metallic surface is covered by typical periodically repeated microstructures, which interact with visible light and bring iridescent appearance to the laser markings due to [...] Read more.

Laser-induced coloration on metallic surfaces has emerged as a clean technology to prepare visual designs. After laser processing, the metallic surface is covered by typical periodically repeated microstructures, which interact with visible light and bring iridescent appearance to the laser markings due to the structural color effect. Although many studies have focused on this topic, the necessity of iridescent surfaces with moderate optical reflectance still needs to be addressed. In general, structural colors are shiny with high brightness. There are troubles in certain cases because shiny markings with excessive reflectance may be harmful to human eyes. In this work, we prepared iridescent an AISI444 stainless steel surface via femtosecond laser processing. By studying the influence of surface microstructures on the coloration and reflectance, suitable laser parameters for producing markings with moderate reflectance were discussed. The contribution of intrinsic colors of the chemical compositions in the surface was further analyzed. Full article

(This article belongs to the Topic Laser Processing of Metallic Materials)

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19 pages, 9422 KiB

Open AccessFeature PaperArticle

Response of the Metastable Pitting Corrosion of Laser Powder Bed Fusion Produced Ti–6Al–4V to H⁺ Concentration Changes

by Yuwei Cui, Liangyu Chen, Liqiang Wang, Jun Cheng and Laichang Zhang

Metals 2023, 13(3), 514; https://doi.org/10.3390/met13030514 - 3 Mar 2023

Cited by 13 | Viewed by 1881

Abstract

There is limited research on metastable pitting corrosion in an acidic environment, and acid is a major challenge for material corrosion. Therefore, this work investigated the metastable pitting corrosion of laser powder bed fusion (LPBF)-produced Ti–6Al–4V, in Hank’s solution, at different pH values [...] Read more.

There is limited research on metastable pitting corrosion in an acidic environment, and acid is a major challenge for material corrosion. Therefore, this work investigated the metastable pitting corrosion of laser powder bed fusion (LPBF)-produced Ti–6Al–4V, in Hank’s solution, at different pH values (pH = 3, 5, and 7). This work investigated the effect of acid on the characteristics of passive films, as well as the change in metastable pitting behavior. Based on the results of electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS), the passive film will be inhibited and dissolved under the influence of H⁺. The higher the concentration of H⁺, the thinner the passive film. Potentiodynamic polarization tests reveal that LPBFed Ti–6Al–4V in Hank’s solution, at pH 3, has more obvious metastable pitting corrosion. This is because the higher the H⁺ concentration, the more Cl^- is adsorbed on the surface of the passive film, which is prone to generate soluble chlorides by competitive adsorption with oxygen atoms and thus develop into metastable pitting corrosion. Full article

(This article belongs to the Topic Laser Processing of Metallic Materials)

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18 pages, 6821 KiB

Open AccessArticle

Properties Evaluations of Topology Optimized Functionally Graded Lattice Structures Fabricated by Selective Laser Melting

by Yangli Xu, Guangyao Han, Guoqin Huang, Tingting Li, Jiaxu Xia and Donghai Guo

Materials 2023, 16(4), 1700; https://doi.org/10.3390/ma16041700 - 17 Feb 2023

Cited by 5 | Viewed by 2650

Abstract

Owning to their lightweight characteristic and high performance, functionally graded lattice structures (FGLSs) show great potential in orthopedics, automotive industries and aerospace applications. Here, two types of uniform lattice structures (ULSs) with RD = 0.50 and 0.20, and two types of FGLSs with [...] Read more.

Owning to their lightweight characteristic and high performance, functionally graded lattice structures (FGLSs) show great potential in orthopedics, automotive industries and aerospace applications. Here, two types of uniform lattice structures (ULSs) with RD = 0.50 and 0.20, and two types of FGLSs with RD = 0.30–0.50 and RD = 0.20–0.40, were designed by topology optimization and fabricated by SLM technology. Subsequently, their surface morphology, compressive deformation behavior and energy absorption abilities were evaluated by use of the finite element method (FEM) and compression tests. From these results, both elastic modulus and yield strength of specimens decreased with the lowering of the RD value. ULSs had a uniform deformation behavior with bending and bulking of struts, while FGLSs presented a mixed deformation behavior of different layers. Additionally, the energy absorption capability (W_v) of specimens was proportional to the RD value. When the value of RD increased from 0.20 to 0.50, the W_v of specimens increased from 0.3657 to 1.7469 MJ/m³. Furthermore, mathematical models were established successfully to predict the mechanical properties of FGLSs with percentage deviations < 10%. This work provides a comprehensive understanding regarding how to design and manufacture FGLSs with the properties desired for satisfying the demand of different application scenarios. Full article

(This article belongs to the Topic Laser Processing of Metallic Materials)

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13 pages, 21237 KiB

Open AccessArticle

The Resistance to Wear and Thermal Cracking of Laser Surface Engineered P20 Steel

by Kangpei Zhao, Guanghua Yan, Jinhong Li, Wenwu Guo, Jianfeng Gu and Chuanwei Li

Coatings 2023, 13(1), 97; https://doi.org/10.3390/coatings13010097 - 5 Jan 2023

Cited by 9 | Viewed by 1658

Abstract

This study reports the microstructure and surface properties of P20 steel processed by laser surface engineering (involving surface hardening and melting), which are carried out using a fiber laser with the maximum power of 2 kW. Ultrafine martensite laths with high boundary density [...] Read more.

This study reports the microstructure and surface properties of P20 steel processed by laser surface engineering (involving surface hardening and melting), which are carried out using a fiber laser with the maximum power of 2 kW. Ultrafine martensite laths with high boundary density are formed both in the laser surface hardened layer and in the melted layer. This dramatically improves the surface hardness of the P20 steel. However, the laser surface melted layer exhibits a relatively lower hardness than the laser surface hardened layer. It can be attributed to the remarkable autotempering effect and the vaporization of alloy elements in the melted layer. The wear resistance and thermal cracking resistance of the samples treated by laser surface engineering show a significant improvement compared with the as received material. The surface hardened layer exhibits superior wear and thermal cracking resistance due to its relatively high surface hardness and plastic deformation resistance, which can effectively suppress the formation of cracks during wear and thermal cracking tests. Full article

(This article belongs to the Topic Laser Processing of Metallic Materials)

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