Final Material Research Articles

A Comparative Study of Three Approaches to Fibre's Surface Functionalization.

Polyester-based scaffolds are of research interest for the regeneration of a wide spectrum of tissues. However, there is a need to improve scaffold wettability and introduce bioactivity. Surface modification is a widely studied approach for improving scaffold performance and maintaining appropriate bulk properties. In this study, three methods to functionalize the surface of the poly(lactide-co-ε-caprolactone) PLCL fibres using gelatin immobilisation were compared. Hydrolysis, oxygen plasma treatment, and aminolysis were chosen as activation methods to introduce carboxyl (-COOH) and amino (-NH2) functional groups on the surface before gelatin immobilisation. To covalently attach the gelatin, carbodiimide coupling was chosen for hydrolysed and plasma-treated materials, and glutaraldehyde crosslinking was used in the case of the aminolysed samples. Materials after physical entrapment of gelatin and immobilisation using carbodiimide coupling without previous activation were prepared as controls. The difference in gelatin amount on the surface, impact on the fibres morphology, molecular weight, and mechanical properties were observed depending on the type of modification and applied parameters of activation. It was shown that hydrolysis influences the surface of the material the most, whereas plasma treatment and aminolysis have an effect on the whole volume of the material. Despite this difference, bulk mechanical properties were affected for all the approaches. All materials were completely hydrophilic after functionalization. Cytotoxicity was not recognized for any of the samples. Gelatin immobilisation resulted in improved L929 cell morphology with the best effect for samples activated with hydrolysis and plasma treatment. Our study indicates that the use of any surface activation method should be limited to the lowest concentration/reaction time that enables subsequent satisfactory functionalization and the decision should be based on a specific function that the final scaffold material has to perform.

Different methods of synthesizing poly(glycerol sebacate) (PGS): A review.

Poly(glycerol sebacate) (PGS) is a biodegradable elastomer that has attracted increasing attention as a potential material for applications in biological tissue engineering. The conventional method of synthesis, first described in 2002, is based on the polycondensation of glycerol and sebacic acid, but it is a time-consuming and energy-intensive process. In recent years, new approaches for producing PGS, PGS blends, and PGS copolymers have been reported to not only reduce the time and energy required to obtain the final material but also to adjust the properties and processability of the PGS-based materials based on the desired applications. This review compiles more than 20years of PGS synthesis reports, reported inconsistencies, and proposed alternatives to more rapidly produce PGS polymer structures or PGS derivatives with tailor-made properties. Synthesis conditions such as temperature, reaction time, reagent ratio, atmosphere, catalysts, microwave-assisted synthesis, and PGS modifications (urethane and acrylate groups, blends, and copolymers) were revisited to present and discuss the diverse alternatives to produce and adapt PGS.

Ni-rich cathode material with isolated porous layer hindering crack propagation under 4.5 V high cut-off voltage cycling

This study reports on a preparation of novel Ni-rich cathode material with isolated porous layer and its application into cathode in lithium ion batteries extending cut-off potential into 4.5 V. Using intermittent addition of Al salt during co-precipitation of NixCo1-x(OH)2 (0 < x < 1), the isolated porous layer is easily formed inside the final active material particles maintaining overall mechanical integrity and their spherical shape without the change of external particle morphology. Even under severe cut-off potential of 4.5 V, volume expansion/contraction by anisotropic mechanical stress from hexagonal 2 to 3 (H2 → H3) phase transition is greatly reduced by hindering inner particle crack propagation into the external area at particle surface. Due to this phenomena, 227 mAh/g initial capacity at 0.1C was obtained upon 86 mol% of Ni content, with 75 % cathode capacity retention after 100 cycles under 1C, which is highest available capacity value among ever reported. Under full cell configuration, capacity retention at 100 cycles was 77 % and total available energy was increased into 15 % when compared with normal cycling condition of 4.3 V cut-off. From microtomic transmission electron microscope analysis, the porosity of inner particle was maintained as low as 6.67 % under 12 % increase of average primary particle size even after 100 cycles under 4.5 V cut-off voltage. From our advanced utilization of capacity and cut-off voltage, available energy in full cell application of our Ni-rich cathode material exhibited 20 % increase when compared with 4.3 V cut-off voltage.

The preparation of conjugated microporous polymer composite materials with montmorillonite template and its improvement in photocatalytic degradation for multiple antibiotics

Photocatalytic technology is considered to be one of the most promising technologies for the removal of organic contaminants. Conjugated Microporous Polymers and their composites are considered to be an effective material for degrading antibiotic contamination, due to their high specific surface area, excellent chemical stability and certain photocatalytic activity. Herein, we synthesized a new type of CMP composite material (PAF-Mt) with montmorillonite template to improve the photocatalytic properties. The results showed that the incorporation of montmorillonite template adjusted electronic band structures of final material, significantly enhanced its photocatalytic activity, and showed excellent photocatalytic efficiency for ofloxacin, tetracycline, ciprofloxacin and chloramphenicol. The efficiencies got increased markedly (325% to 766%) compared to the PAFs without template addition.

The Handwritten Recipe Notebook as a Place of Memory

A handwritten recipe notebook is not a mere domestic collection of recipes, but a material support for an immaterial tradition that combines culinary knowledge with commensality practices. These are formalized texts (a title, a list of ingredients, and directions) activated through the oral performance of a formalized setting (the food preparation process), which combines sequences of gestures instead of (or together with) words, or/and through a writing activity (copying a model or transcribing the recipe after dictation). The final material artefact (namely the dish and the written recipe) incorporates the syncretic and immaterial memories of all previous performances. A recipe notebook is not a simple anthology of texts either, it is instead a subjective “critical edition” which grows page by page, according to imperceptible selection criteria; with the passing of time, the pages become impregnated with smells, traces of pots of oil or sugar, children’s fingerprints, figurative drawings, etc.

Human-derived cytokine functionalized sericin/agarose composite gel material with cell proliferation-promoting activity fabricated using genetically engineered silk for medical application

Functional biomaterials have great potential for future medical application. Although functional biomaterials produced from genetically engineered silk are promising, it can be challenging to simultaneously maintain their structural stability and functionality. Herein, a stable and functional sericin protein-based composite gel biomaterial with improved cell-proliferation activity was designed and fabricated using a genetically engineered silk material containing human-derived cytokines combined with agarose molecules. This composite gel material is porous and consists of a sericin protein network, agarose molecular network, and sericin-agarose crossing (by hydrogen bond linkage) network; a complex structure that improved the stability and mechanical performance of the final material by approximately 2-fold. Moreover, the composite material showed to efficiently and gradually release the active cytokines FGF-1 and FGF-2 for up to 3 weeks, thereby promoting significant fibroblast proliferation by activating the extracellular signal-regulated kinase pathway. Notably, this composite gel caused no obvious cytotoxicity or severe inflammation responses in vitro nor in vivo. Taken together, this composite gel material has medical application potential for damaged tissue repair and regeneration. Moreover, this report demonstrates that application of agarose in biomaterials can aid on the clinical application of genetically engineered silk materials in the future.

Ionic liquid-based periodic mesoporous organosilicas: Metal/solvent-free synthesis of formamides and formamidines

We prepared a novel ionic liquid-based Periodic Mesoporous Organosilicas (PMOs) using a post-synthetic method. First, PMO containing amine unit (PMO-NH) was prepared as a result of the co-condensation of amine bis-silane precursor [bis[3-(triethoxysilyl)propyl]amine] and tetraethylorthosilicate (TEOS) in the presence of pluronic-123 under acidic conditions. In a second step, the amine units (NH) were reacted with perchloric acid and yielded ionic-PMO material (PMO-NH2+ClO4−). The materials possessed a hexagonal lattice with the highly ordered mesostructured being retained after the functionalization as evidenced by X-ray diffraction (XRD) analysis. The N2 adsorption-desorption measurement revealed that the final material (PMO-NH2+ClO4−) had a high BET surface area (350 m2/g) and pore size (4.8 nm). The obtained material was subsequently evaluated as a heterogeneous catalyst in the coupling reaction of amine/formic acid towards formamides and also in the preparation of formamidine derivatives. The reactions between various aryl amines and formic acid or triethyl orthoformate could proceed smoothly in the presence of PMO-NH2+ClO4−, giving a high yield of 85–99% with great selectivity (> 99%). This outstanding catalytic performance can be attributed to the presence of acidic ionic sites together with a high surface area of the obtained material.

Balancing Functionality and Printability: High-Loading Polymer Resins for Direct Ink Writing.

Although direct ink writing (DIW) allows the rapid fabrication of unique 3D printed objects, the resins-or "inks"-available for this technique are in short supply and often offer little functionality, leading to the development of new, custom inks. However, when creating new inks, the ability of the ink to lead to a successful print, or the "printability," must be considered. Thus, this work examined the effect of filler composition/concentration, printing parameters, and lattice structure on the printability of new polysiloxane inks incorporating high concentrations (50-70 wt%) of metallic and ceramic fillers as well as emulsions. Results suggest that strut diameter and spacing ratio have the most influence on the printability of DIW materials and that the printability of silica- and metal-filled inks is more predictable than ceramic-filled inks. Additionally, higher filler loadings and SC geometries led to stiffer printed parts than lower loadings and FCT geometries, and metal-filled inks were more thermally stable than ceramic-filled inks. The findings in this work provide important insights into the tradeoffs associated with the development of unique and/or multifunctional DIW inks, printability, and the final material's performance.

Facile ultrasonic-assisted one-step preparation of sugarcane bagasse carbon sorbent for bio-based odor removal cat litter formulation

To reduce the cost of adsorbents for the removal of cat urine odor there has been concerted research efforts to produce functionalized porous carbon from waste biomass. In this work, a cost-effective and environmentally friendly method was used to prepare a carbon adsorbent (AC-SNP) from sugarcane bagasse through ultrasonic-assisted impregnation of mixed HNO3/H3PO4 on bagasse prior to carbonization. Ultrasonication enhanced structural deformation of bagasse and enriched the N and O-containing groups prior to cabonization which allowed the final carbon material to have increased specific surface area of 1603.1 m2/g and porosity of 1.3858 cm3·g−1 (including micro- and meso-pores), and increased surface functionality of -COOH, -OH, pyrrolic N, and pyridinic N groups. The adsorption capacity of the carbon material for 3-mercapto-3-methyl-1-butanol (MMB), a volatile cat urine component, was up to 207.12 mg/g at 25 °C, and the heterogenous multi-layer Freundlich model and Pseudo-second-order model were used to explain the adsorption mechanism. Density functional theory (DFT) calculations showed that there are electrostatic interactions and hydrogen bonding between the O- and N-containing groups and MMB molecules. AC-SNP was found to be nontoxic in a cat litter formulation, and removes 99.87% volatile MMB at a low loading ratio of 2 wt%. The fabricated sugarcane bagasse-based cat litter (SB_CL) formulation also has anti-bacterial properties, and so has significant commercialization prospects.

Biomass-Derived Porous Carbon with a Good Balance between High Specific Surface Area and Mesopore Volume for Supercapacitors.

Porous carbon has been one desirable electrode material for supercapacitors, but it is still a challenge to balance the appropriate mesopore volume and a high specific surface area (SSA). Herein, a good balance between a high SSA and mesopore volume in biomass-derived porous carbon is realized by precarbonization of wheat husk under air atmosphere via a chloride salt sealing technique and successive KOH activation. Due to the role of molten salt generating mesopores in the precarbonized product, which can further serve as the active sites for the KOH activation to form micropores in the final carbon material, the mesopore-micropore structure of the porous carbon can be tuned by changing the precarbonization temperature. The appropriate amount of mesopores can provide more expressways for ion transfer to accelerate the transport kinetics of diffusion-controlled processes in the micropores. A high SSA can supply abundant sites for charge storage. Therefore, the porous carbon with a good balance between the SSA and mesopores exhibits a specific gravimetric capacitance of 402 F g-1 at 1.0 A g-1 in a three-electrode system. In a two-electrode symmetrical supercapacitor, the biomass-derived porous carbon also delivers a high specific gravimetric capacitance of 346 F g-1 at 1.0 A g-1 and a good cycling stability, retaining 98.59% of the initial capacitance after 30,000 cycles at 5.0 A-1. This work has fundamental merits for enhancing the electrochemical performance of the biomass-derived porous carbon by optimizing the SSA and pore structures.

Improving Fmoc Solid Phase Synthesis of Human Beta Defensin 3.

Human β-defensin 3, HBD-3, is a 45-residue antimicrobial and immunomodulatory peptide that plays multiple roles in the host defense system. In addition to interacting with cell membranes, HBD-3 is also a ligand for melanocortin receptors, cytokine receptors and voltage-gated potassium channels. Structural and functional studies of HBD-3 have been hampered by inefficient synthetic and recombinant expression methods. Herein, we report an optimized Fmoc solid-phase synthesis of this peptide using an orthogonal disulfide bonds formation strategy. Our results suggest that utilization of an optimized resin, coupling reagents and pseudoproline dipeptide building blocks decrease chain aggregation and largely improve the amount of the target peptide in the final crude material, making the synthesis more efficient. We also present an alternative synthesis of HBD-3 in which a replacement of a native disulfide bridge with a diselenide bond improved the oxidative folding. Our work enables further biological and pharmacological characterization of HBD-3, hence advancing our understanding of its therapeutic potential.

Effect of nano-phased bismuth–tin alloy surface coating on tribo-mechanical properties of basalt fiber reinforced composites

A novel method for coating basalt fiber with a eutectic bismuth–tin (Bi–Sn) mixture was developed. Bi-Sn nanoparticles were synthesized using a sol-gel process and deposited on basalt fiber by chemical vapor deposition, with the aim of evaluating the tribo-mechanical properties of the final epoxy-composite material. X-ray diffraction showed that the synthesized Bi–Sn alloy was highly polycrystalline with equal distribution of tetragonal and orthorhombic Bi–Sn polymorph phases with crystallite sizes between 17 and 55 nm. High-resolution electron microscopy revealed that the sample possesses highly fused, flake-stacked planar layers, with 50 nm-thick flakes of variable length. Elemental analysis determined that the alloy contains 57% Bi (at.wt%), and Raman spectroscopy confirmed the characteristic Bi–Sn fingerprint peaks of 148, 201, and 397 cm−1. Thermal analysis of the composites showed good thermal stability with only 4% mass loss at 700 °C. Furthermore, an increase in the Bi–Sn loading enhanced the tribo-tensile properties. It was found that at a Bi-Sn gravimetric loading of 0.2 g the composite yielded the highest ultimate tensile strength of 303 MPa compared to the reference (154 MPa), even as the Young's moduli showed a decrease in elasticity by up to 24.99%. Moreover, the tribology results showed a good friction coefficient (0.5), with a negligible wear rate (4.53 × 10−8 mm3/Nm) and relatively low wear volume (0.118 mm3). Thus, the proposed method resulted in alloy composites with improved tribo-mechanical properties, and has potential applicability in the development of lead-free solders.

Low-temperature sol–gel synthesis of magnetite superparamagnetic nanoparticles: Influence of heat treatment and citrate–nitrate equivalence ratio

Spinel ferrite nanoparticles are a remarkably versatile group of metal oxides with unique magnetic and electronic properties, making them promising candidates for certain electronic, biomedical, and environmental applications. Magnetite nanoparticles are obtained using complex synthesis methodologies that require inert atmospheres, additives to induce pH changes, expensive or toxic reagents, or complex equipment. In this work, a new approach to obtain superparamagnetic magnetite nanoparticles using citrate–nitrate sol–gel synthesis followed by heat treatment is presented. Iron nitrate and citric acid were added in different equivalence ratios (χ) (citrate/nitrate = 0.30, 0.85, and 1.40). The thermal behaviour of the xerogels was evaluated using thermal analysis techniques, and the results indicated that decreasing the equivalence ratio decreased the temperature required for magnetite formation, and the different release rates of reducing gases influenced the properties of the final material formed. The heat-treatment temperatures for the synthesis with the optimal χ were 130, 150, and 170 °C for 2, 4, and 8 h. Each condition was characterised in terms of the structure and magnetic properties of the product. The results showed that the prepared iron oxide nanoparticles were in the magnetite phase (Fe3O4) and possessed a crystallite size of 4.5–6.0 nm and average particle size of <10 nm. The magnetite nanoparticles displayed superparamagnetic behaviour, with a saturation magnetisation of up to 26.24 emu/g and remanent magnetisation of almost zero. Therefore, these superparamagnetic magnetite nanoparticles have excellent potential for biomedical and environmental applications.

Evaluation of the effect of different complete denture impression techniques on dental anxiety levels

Background: There are several different impression materials and techniques utilized in the fabrication of complete dentures.&#x0D; Aim of the study: To determine the anxiety levels and the clinical procedure time for maxillary completely edentulous patients by the use of two different impression techniques; the use of a low-fusing green stick compound along with zinc oxide eugenol impression paste and addition silicone (polyvinyl siloxane) along with light body material.&#x0D; Materials and Methods: Twelve maxillary edentulous subjects aged between 44 and 68 were randomly recruited for the study. After having the primary impression two special trays were fabricated for each patient; the first tray for the sectional border moulding group using impression compound along with ZOE final impression material (Group Z), and the second tray for the single-step border moulding technique using additional polyvinyl siloxane impression along with light body final impression materials (Group P). Comparisons between the two groups' procedure time and patients' visual analog scale (VAS) levels were made.&#x0D; Results: The results showed that group P had significantly reduced the VAS compared to group Z 17.5±12.88 and 57.5±16.03, respectively (P=0.000). The mean total procedure times for single-step border moulding and sectional border moulding impression techniques were 12.25±5.16 and 27.5±4.00, respectively (P=0.000). Also, a significant association between the treatment groups and VAS scores was observed by the multiple regression analysis model (P=0.000).&#x0D; Conclusion: As a result of the better patients' perceptions and reduced clinical time, the study findings suggested using a single-step border moulding technique in the upper arch together with additional vinyl silicon material.

Removal Mechanism and Electrochemical Milling of (TiB+TiC)/TC4 Composites.

Titanium matrix composite (TiB+TiC)/TC4 has excellent physical properties and is a completely new composite material with great application prospects in the next generation of the aerospace field. However, there are problems, such as tool loss and material overheating, when using conventional processing methods. Electrochemical milling is a low-cost, high-efficiency processing method for difficult-to-machine metal materials with no tool wear. In this research, the feasibility of the electrochemical milling of (TiB+TiC)/TC4 and removal mechanisms during processing was reported for the first time. The feasibility of electrochemical milling is verified by the current efficiency experiment and basic processing experiment. Through the adjustment of the processing parameters, the final material removal rate increased by 52.5% compared to that obtained in the first processing, while the surface roughness decreased by 27.3%. The removal mechanism during processing was further performed based on the current efficiency experiment; three stages were observed and concluded during the electrolytic dissolution. This research proved that electrochemical milling is an excellent low-cost method for roughing and semi-finishing (TiB+TiC)/TC4 composites and provides guidance for better electrochemical milling in the titanium matrix composites.

Enhanced Property Tunability of Doubly Doped Semiconductor Nanomaterials Using the Cluster Seed Method

Semiconductor Quantum Dots (QDs) have great potential in applications for renewable energy generation due to their size-tunable redox potentials. They may be prepared with different morphologies and coated to create complex heterostructures. Doping of semiconductor nanomaterials is another mechanism to realize property tunability, and doped QDs are playing an increasing role in green energy generation applications. In 2013 our group reported a method to create a batch of doped quantum dots where each particle was embedded with the same number of guest ions, thus circumventing Poisson statistics. This was accomplished by nucleating the QD around an organometallic seed cluster that contains guest ions. As a result, each QD has the same number of dopants, which eliminates problems due to inhomogeneity of the guest ion stoichiometry. These materials were studied using time-resolved X-ray absorption spectroscopy, which allows us to characterize the electronic and coordination structure in both the ground and excited states.Current research reveals the potential to doubly dope semiconductors using cluster seeding, and that the originating organometallic structure may be represented in the final material product. To this end, ZnCdSe nanowires were prepared in the presence of (MnTe)4 cluster seeds. The results reveal that Mn(2+) has been successfully incorporated into the host matrix, while temperature dependent optical measurements suggest significantly enhanced semiconductor exciton-magnetic dopant interactions in materials prepared by cluster seeding compared to doped control samples. This could be due to ferromagnetic Mn-Mn interactions in the host resulting from enhanced exchange coupling mediated by highly spin-orbit coupled tellurium bridging. Consequently, cluster seeding may be used to "dope the dopants", affording a heretofore unrealized method for developing designer materials with enhanced electronic and optical properties. Figure 1

Procedure to implement shear evolution in fast rolling models with online capability on the example of an aluminum flat rolling process

The rolling process induces a heterogeneous deformation over the rolling stock height. The causes are the frictional shear stress between the contacting surfaces and the roll gap geometry. They induce a complex material flow within the rolling stock describable by the shear evolution. The shear evolution has a significant impact on rolling values like grain size and crystallographic texture and therefore on the final material properties of the rolled product. Industry and academia use fast rolling models for flat rolling processes to predict the material properties due to their short computation time. The time advantage enables online applicability to adapt processes in real time or to evaluate the influence of different process conditions several times within seconds. However, these models have a limitation regarding the shear evolution. They do not consider all relevant influences or apply simplifying assumptions, valid only for specific rolling cases. This work presents a general approach to extend fast rolling models to consider the shear evolution without any restrictions to specific rolling cases. The approach derives the shear evolution as shear angle alpha evolution based on FE simulations. The shear angle alpha is a geometrical description and not influenced by rotations, which occur during the rolling process. This enables an enhanced and simple analysis of the material flow. The outcome is an extended model that completely describes the deformation along a deformation path and enables the calculation of each desired deformation value (strain, deformation gradient, velocity gradient, etc.).

Sustainable Synthesis of Highly Functionalized Activated Carbon using Plasma Technology.

Surface functionalized activated carbon (SFAC) has been used for several applications, including adsorption, catalysis and energy storage materials. Existing chemical and physical activation methods for surface functionalization are mostly identified as expensive, inefficient, and non-green methods. Plasma, known as the fourth state of matter, has recently been recognized as an attractive and sustainable method for introducing a higher degree of surface functionality to activated carbon. It also improves the bulk chemical structure and the properties of SFAC. The surface functionalization process is governed by discharge gas, discharge source, discharge efficiency and discharge time. The majority of researchers have utilized oxygen plasma as the discharge gas. However, ammonia, carbon dioxide, atmospheric air, specific gases such as chlorine and hydrogen sulfide, and neutral gases such as nitrogen and argon have also been used as the discharge gas. These plasma activations were conducted under different power conditions (W to kW) and varying treatment times (seconds to hours) using different plasma sources such as dielectric barrier discharge (DBD), arc, radio frequency (RF) and microwave (MW) for the surface functionalization. Most of the researchers have experienced both positive and negative co-relationships between principal parameters and surface functional groups (SFGs), surface area, porosity and other surface features such as roughness and hydrophilicity. However, a comprehensive review on the effects of these parameters on the final material properties is lacking. Therefore, this Review focuses on the recent developments in the utilization of plasma as a surface activation technique for activated carbon. Furthermore, an in-depth analysis of the relationship between experimental parameters and the resultant surface features of activated carbon is carried out and discussed. The functionalization mechanisms related to plasma activation have also been illustrated. The aging effect, which negatively impacts surface functionalized activated carbon, is also emphasized. Finally, the recent advances in applications of SFAC, challenges and future perspectives are discussed in detail.

The effect of microwave energy on sintering of an austenitic stainless steel reinforced with boron carbide

Microwave heating has emerged as an alternative to traditional sintering methods because it consumes less energy and requires shorter processing times. The use of microwave energy in the processing of austenitic stainless steel AISI 316L reinforced with dispersed boron carbide particles was investigated in this study. Different processing parameters were used to investigate the effect of sintering time and temperature, as well as the weight percentage of the ceramic added to the steel matrix, on the final material properties. The compressibility curve, elastic relaxation, and geometric density of green compacts were used to investigate their physical properties. The Archimedes method was used to determine density, and the statistical treatment of analysis of variance was used to determine porosity. Images obtained using optical microscopy and scanning electron microscopy revealed the formation of a second phase in different volumes. The results showed that 1100 °C and a 15-minute plateau were sufficient to sinter the material. AISI 316L samples containing 3 wt.% boron carbide demonstrated greater volumetric formation of secondary phases, resulting in a significant increase in the hardness of the austenitic composite developed.

Evaluation of narrowed weld pool shapes and their effect on resulting potential defects during deep penetration laser beam welding

This study presents mechanisms of the evolution of a narrowed region in the weld pool center during deep penetration laser beam welding. In numerous numerical studies presented in this study, it was also found that the local reduction of the weld pool size can cause detrimental effects on the melt flow behavior and the resulting properties of the welds. A particularly large influence of this effect was identified in three aspects. First, the local variation of the solidification sequence of the weld pool causes an increase in the hot-cracking susceptibility due to a locally delayed solidification. Second, it was proven that a change in the local length and width of the weld pool is associated with an adverse impact on the potential flow routes of the molten material that induces stronger local variations of its solidification. Thus, the element mixing, e.g., during the welding with filler materials, is blocked. This leads to a nonhomogeneous chemical composition of the final weld and can cause undesired effects on the final material properties. Finally, another observed effect is related to the reduced ability of process pores to reach the top surface. As this type of porosity is usually produced around the keyhole tip, the change of the fluid flow regime above this area plays a significant role in determining the final path of the pores until the premature solidification in the middle of the weld pool captures them. This study summarizes mainly numerical results that were supported by selected experimental validation results.