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13 pages, 3208 KiB

Open AccessArticle

The Effect of Powder Reuse on Electron Beam Melting for Biomedical Implants

by Akshay Mundayadan Chandroth, Paula Milena Giraldo-Osorno, Lars Nyborg, Anders Palmquist and Yu Cao

Materials 2024, 17(19), 4701; https://doi.org/10.3390/ma17194701 - 25 Sep 2024

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Abstract

The ability of additive manufacturing to generate intricate structures has led to its popularity and widespread use in a variety of applications, ranging from the production of biomedical implants to aircraft components. Additive manufacturing techniques can overcome the limitations of the traditional manufacturing [...] Read more.

The ability of additive manufacturing to generate intricate structures has led to its popularity and widespread use in a variety of applications, ranging from the production of biomedical implants to aircraft components. Additive manufacturing techniques can overcome the limitations of the traditional manufacturing methods to create complex near-net-form structures. A vast array of clinical applications effectively employ Ti-6Al-4V as a biomaterial. The evolution of additive manufacturing has accelerated the development of patient-specific implants. The surface characteristics play a critical role in tissue healing and adaptation to implants. The present research set out to examine the effects of powder recycling with respect to the powder itself and the surface properties resulting from the electron beam melting (EBM) of the implant material. The printed implants, as well as the powder samples, underwent morphological, surface chemistry, and microstructure analyses. The in vitro cytotoxicity was evaluated with THP-1 macrophages. The overall microstructure of the implant samples showed little variation in terms of powder recycling based on the results. Higher oxygen levels were found in the solid and lattice sections of those implants manufactured with batches of recycled powder, along with marginally better cell viability. This emphasizes how crucial powder quality is to the process of additive manufacturing. Full article

(This article belongs to the Special Issue Advanced Welding Technologies and Additive Manufacturing of Alloys and Metals (2nd Edition))

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17 pages, 11545 KiB

Open AccessArticle

Considerations for Tungsten Carbide as Tooling in RFSSW

by Ruth Belnap, Taylor Smith, Arnold Wright and Yuri Hovanski

Materials 2024, 17(15), 3799; https://doi.org/10.3390/ma17153799 - 1 Aug 2024

Viewed by 703

Abstract

Tool wear is a key issue for the manufacturing performance of refill friction stir spot welding in high-volume manufacturing environments. As such, the aim of this study is to examine conditions in which tungsten carbide with a cobalt binder can succeed as a [...] Read more.

Tool wear is a key issue for the manufacturing performance of refill friction stir spot welding in high-volume manufacturing environments. As such, the aim of this study is to examine conditions in which tungsten carbide with a cobalt binder can succeed as a tool material in the spot welding of 2029 aluminum for a sustained lifetime. Critical factors are shown herein to include cleanliness and thermal management. The life of a WC-Co toolset is demonstrated to be approximately 2998 welds, which is of the same scale as conventional steel tooling. With a WC-Co shoulder and probe, the H13 clamp showed the only significant wear. Full article

(This article belongs to the Special Issue Advanced Welding Technologies and Additive Manufacturing of Alloys and Metals (2nd Edition))

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24 pages, 13962 KiB

Open AccessArticle

Study of Eddy Current Testing Ability on SLM Aluminium Alloy

by Matúš Geľatko, Michal Hatala, František Botko, Radoslav Vandžura and Jiří Hajnyš

Materials 2024, 17(14), 3568; https://doi.org/10.3390/ma17143568 - 18 Jul 2024

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Abstract

The detection of defects in aluminium alloys using eddy current testing (ECT) can be restricted by higher electrical conductivity. Considering the occurrence of discontinuities during the selective laser melting (SLM) process, checking the ability of the ECT method for the mentioned purpose could [...] Read more.

The detection of defects in aluminium alloys using eddy current testing (ECT) can be restricted by higher electrical conductivity. Considering the occurrence of discontinuities during the selective laser melting (SLM) process, checking the ability of the ECT method for the mentioned purpose could bring simple and fast material identification. The research described here is focused on the application of three ECT probes with different frequency ranges (0.3–100 kHz overall) for the identification of artificial defects in SLM aluminium alloy AlSi10Mg. Standard penetration depth for the mentioned frequency range and identification abilities of used probes expressed through lift-off diagrams precede the main part of the research. Experimental specimens were designed in four groups to check the signal sensitivity to variations in the size and depth of cavities. The signal behavior was evaluated according to notch-type and hole-type artificial defects’ presence on the surface of the material and spherical cavities in subsurface layers, filled and unfilled by unmolten powder. The maximal penetration depth of the identified defect, the smallest detectable notch-type and hole-type artificial defect, the main characteristics of signal curves based on defect properties and circumstances for distinguishing between the application of measurement regime were stated. These conclusions represent baselines for the creation of ECT methodology for the defectoscopy of evaluated material. Full article

(This article belongs to the Special Issue Advanced Welding Technologies and Additive Manufacturing of Alloys and Metals (2nd Edition))

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21 pages, 12514 KiB

Open AccessArticle

Analysis of the Microstructure and Mechanical Performance of Resistance Spot-Welding of Ti6Al4V to DP600 Steel Using Copper/Gold Cold-Sprayed Interlayers

by Krzysztof Szwajka, Joanna Zielińska-Szwajka, Marek Szewczyk, Marwan T. Mezher and Tomasz Trzepieciński

Materials 2024, 17(13), 3251; https://doi.org/10.3390/ma17133251 - 2 Jul 2024

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Abstract

In this article, an attempt was made to join DP600 steel and Ti6Al4V titanium alloy sheets by resistance spot-welding (RSW) using an interlayer in the form of Cu and Au layers fabricated through the cold-spraying process. The welded joints obtained by RSW without [...] Read more.

In this article, an attempt was made to join DP600 steel and Ti6Al4V titanium alloy sheets by resistance spot-welding (RSW) using an interlayer in the form of Cu and Au layers fabricated through the cold-spraying process. The welded joints obtained by RSW without an interlayer were also considered. The influence of Cu and Au as an interlayer on the resulting microstructure as well as mechanical properties (shear force and microhardness) of the joints were determined. A typical type of failure of Ti6Al4V/DP600 joints produced without the use of an interlayer is brittle fracture. The microstructure of the resulting joint consisted mainly of the intermetallic phases FeTi and Fe₂Ti. The microstructure of the Ti6Al4V/Au/DP600 joint contained the intermetallic phases Ti₃Au, TiAu, and TiAu4. The intermetallic phases TiCu and FeCu were found in the microstructure of the Ti6Al4V/Cu/DP600 joint. The maximum tensile/shear stress was 109.46 MPa, which is more than three times higher than for a welded joint fabricated without the use of Cu or Au interlayers. It has been observed that some alloying elements, such as Fe, can lower the martensitic transformation temperature, and some, such as Au, can increase the martensitic transformation temperature. Full article

(This article belongs to the Special Issue Advanced Welding Technologies and Additive Manufacturing of Alloys and Metals (2nd Edition))

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15 pages, 16362 KiB

Open AccessArticle

Effect of Inconel 718 Filler on the Microstructure and Mechanical Properties of Inconel 690 Joint by Ultrasonic Frequency Pulse Assisted TIG Welding

by Ke Han, Xin Hu, Xinyue Zhang, Hao Chen, Jinping Liu, Xiaodong Zhang, Peng Chen, Hongliang Li, Yucheng Lei and Jinhui Xi

Materials 2024, 17(12), 2857; https://doi.org/10.3390/ma17122857 - 11 Jun 2024

Viewed by 690

Abstract

Ultrasonic frequency pulse assisted TIG welding (UFP-TIG) experiments were conducted to join Inconel 690 alloy (IN690) by adding Inconel 718 alloy (IN718) as the filler. The effect of the filler on the microstructure, mechanical properties, and ductility dip cracking (DDC) susceptibility of IN690 [...] Read more.

Ultrasonic frequency pulse assisted TIG welding (UFP-TIG) experiments were conducted to join Inconel 690 alloy (IN690) by adding Inconel 718 alloy (IN718) as the filler. The effect of the filler on the microstructure, mechanical properties, and ductility dip cracking (DDC) susceptibility of IN690 joints were investigated. The results show that a variety of precipitates, including MC-type carbide and Laves phases, are formed in the weld zone (WZ), which are uniformly dispersed in the interdendritic region and grain boundaries (GBs). The increase in the thickness of the IN718 filler facilitates the precipitation and growth of Laves phases and MC carbides. However, the formation of Laves phases in the WZ exhibits a lower bonding force with the matrix and deteriorates the tensile strength of IN690 joints. Due to the moderate content of Laves phases in the WZ, the IN690 joint with 1.0 mm filler reaches the maximum tensile strength (627 MPa), which is about 96.5% of that of the base metal (BM). The joint with 1.0 mm filler also achieves the highest elongation (35.4%). In addition, the strain-to-fracture tests indicate that the total length of cracks in the joint with the IN718 filler decreases by 66.49% under a 3.8% strain. As a result, the addition of the IN718 filler significantly improves the mechanical properties and DDC resistance of IN690 joints. Full article

(This article belongs to the Special Issue Advanced Welding Technologies and Additive Manufacturing of Alloys and Metals (2nd Edition))

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12 pages, 35525 KiB

Open AccessArticle

AZ91 Magnesium Alloy CMT Cladding Layer Processed Using Friction Stir Processing: Effect of Traverse Speed on Microstructure and Mechanical Properties

by Huichao Zhao, Junqi Shen, Shengsun Hu, Yahui Zhen and Yang Chen

Materials 2024, 17(10), 2348; https://doi.org/10.3390/ma17102348 - 15 May 2024

Cited by 1 | Viewed by 743

Abstract

Friction stir processing (FSP) is a solid-state treating method to enhance the mechanical properties of materials by altering their microstructure. In this study, FSP was applied to the AZ91 magnesium alloy cladding layer prepared using cold metal transition (CMT) technology, and the purpose [...] Read more.

Friction stir processing (FSP) is a solid-state treating method to enhance the mechanical properties of materials by altering their microstructure. In this study, FSP was applied to the AZ91 magnesium alloy cladding layer prepared using cold metal transition (CMT) technology, and the purpose was to investigate the effect of the traverse speed of the H13 steel stirring head under a constant rotation speed on the microstructure and mechanical properties of the cladding layer. The results demonstrated that FSP could effectively decrease the grain size of the cladding layer and lead to the dispersion and dissolution of the coarse β-Mg₁₇Al₁₂ second phase into the α-Mg matrix. The mechanical characteristics of the processed cladding layer were significantly enhanced compared to the unprocessed cladding layer due to the grain refinement and second-phase strengthening induced by FSP. When the stirring head rotation speed was set at 300 r/min, the average microhardness and tensile properties of the specimens showed a tendency of initially increasing and then dropping as the traverse speed increased. The cladding layer, obtained at a traverse speed of 60 mm/min, displayed optimal mechanical properties with an average microhardness, tensile strength, and elongation of 85.6 HV_0.1, 278.5 MPa, and 13.4%, respectively. Full article

(This article belongs to the Special Issue Advanced Welding Technologies and Additive Manufacturing of Alloys and Metals (2nd Edition))

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12 pages, 6444 KiB

Open AccessCommunication

Effect of Welding Gap of Thin Plate Butt Welds on Inherent Strain and Welding Deformation of a Large Complex Box Structure

by Liping Zhang, Genchen Peng, Fan Yang, Zhengyu Meng, Xiaoming Yuan, Yangyang Fan, Wen Li and Lijie Zhang

Materials 2024, 17(9), 1934; https://doi.org/10.3390/ma17091934 - 23 Apr 2024

Viewed by 1076

Abstract

In this study, an effective numerical model was developed for the calculation of the deformation of laser-welded 3 mm 304L stainless steel plates with different gaps (0.2 mm, 0.5 mm, and 1.0 mm). The welding deformation would become larger when the welding gaps [...] Read more.

In this study, an effective numerical model was developed for the calculation of the deformation of laser-welded 3 mm 304L stainless steel plates with different gaps (0.2 mm, 0.5 mm, and 1.0 mm). The welding deformation would become larger when the welding gaps increased, and the largest deformation values along the Z direction, of 4 mm, were produced when the gap value was 1.0 mm. A larger plastic strain region was generated in the location near the weld seam, since higher plastic deformation had occurred. In addition, the tensile stress model was also applied at the plastic strain zone and demonstrated that a larger welding gap led to a wider residual stress area. Based on the above results, inherent deformations for butt and corner joints were calculated according to inherent strain theory, and the welding formation for the complex structure was calculated with different gaps. The numerical results demonstrated that a larger deformation was also produced with a larger welding gap and that it could reach the highest value of 10.1 mm. This proves that a smaller welding gap should be adopted during the laser welding of complex structures to avoid excessive welding deformation. Full article

(This article belongs to the Special Issue Advanced Welding Technologies and Additive Manufacturing of Alloys and Metals (2nd Edition))

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Review

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25 pages, 7905 KiB

Open AccessReview

Review and Analysis of Modern Laser Beam Welding Processes

by Andrzej Klimpel

Materials 2024, 17(18), 4657; https://doi.org/10.3390/ma17184657 - 23 Sep 2024

Viewed by 735

Abstract

Laser beam welding is the most modern and promising process for the automatic or robotized welding of structures of the highest Execution Class, EXC3-4, which are made of a variety of weldable structural materials, mainly steel, titanium, and nickel alloys, but also a [...] Read more.

Laser beam welding is the most modern and promising process for the automatic or robotized welding of structures of the highest Execution Class, EXC3-4, which are made of a variety of weldable structural materials, mainly steel, titanium, and nickel alloys, but also a limited range of aluminum, magnesium, and copper alloys, reactive materials, and even thermoplastics. This paper presents a systematic review and analysis of the author’s research results, research articles, industrial catalogs, technical notes, etc., regarding laser beam welding (LBW) and laser hybrid welding (LHW) processes. Examples of industrial applications of the melt-in-mode and keyhole-mode laser welding techniques for low-alloy and high-alloy steel joints are analyzed. The influence of basic LBW and LHW parameters on the quality of welded joints proves that the laser beam power, welding speed, and Gas Metal Arc (GMA) welding current firmly decide the quality of welded joints. A brief review of the artificial intelligence (AI)-supported online quality-monitoring systems for LBW and LHW processes indicates the decisive influence on the quality control of welded joints. Full article

(This article belongs to the Special Issue Advanced Welding Technologies and Additive Manufacturing of Alloys and Metals (2nd Edition))

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