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The main purpose of the present work is to evaluate, the microstructural and mechanical properties of friction stir welded plates of AZ91D magnesium alloy with 3 mm thickness, and to determine the optimum range of welding conditions.

Microstructure and fractographic studies were carried out using scanning electron microscopy (SEM). Vickers micro hardness test was performed to evaluate the hardness profile in the region of the weld area. The phases in the material were confirmed by X-Ray diffraction (XRD) analysis. Transverse tensile tests were conducted using universal testing machine (UTM) to examine the joint strength of the weldments at different parameters.

Metallographic studies revealed that each zone shown different lineaments depending on the mechanical and thermal conditions. Significant improvement in the hardness was observed between the base material and weldments. Transverse tensile test results of weldments had shown almost similar strength that of base material regardless of welding speed. Fractographic examination indicated that the welded specimens failed due to brittle mode fracture. Through these studies it was confirmed that friction stir welding (FSW) can be used for the welding of AZ91D magnesium alloy.

In the present study, the welding speed varied from 25 mm/min to 75 mm/min, tilt angle varied from 1.5^° to 2.5^° and constant rotational speed of 500 rpm.

Magnesium and aluminum based alloys which are having high strength and low density, used in automotive and aerospace applications can be successfully joined using FSW technique. The fusion welding defects can be eliminated by adopting this technique.

Limited work had been carried out on the FSW of magnesium based alloys over aluminum based alloys. Furthermore, this paper analyses the influence of welding parameters over the microstructural and mechanical properties.

An effective chemical conditioning technique was successfully tested and investigated to control and minimize the chemistry-related damages within mixed metallurgy steam and water cycle of Heller dry cooled combined cycle power plants (CCPPs), in which cooling water and condensate are completely mixed in direct contact condenser. This study aims to perform a comprehensive experimental research in four mixed metallurgy steam and water cycle.

A comprehensive experimental study was carried out in four mixed metallurgy steam and water cycle fabricated with ferrous- and aluminum-based alloys which have various corrosion resistance capabilities in contact with water. Chemical conditioning was conducted using both volatile and non-volatile alkalizing agents, and, to perform chemical conditioning effectively, quality parameters (pH, conductivity, dissolved oxygen, sodium, silica, iron, aluminum and phosphate) were monitored by analyzing grab and online samples taken at eight key sampling points.

Results indicated that pH was the most critical parameter which was not mainly within the recommended ranges of widely used standards and guidelines at all key sampling points that generally increases the occurrence of chemistry-related damages. The other quality parameters were mostly satisfactory.

In this research, the development of a suitable chemical conditioning technique in mixed metallurgy steam and water cycle, fabricated with ferrous and aluminum-based alloys, was studied. The obtained results in this thorough research work was evaluated by comparison with the chemistry limits of the widely used standards and guidelines, and combined use of volatile and solid alkalizing agents was considered as a promising chemical conditioning technique for utilization in mixed metallurgy units of Heller dry cooled CCPPs.

Engineers and scientists are searching for novel materials with high performance on all aspect points of view for the applications including marine, aero and automobile fields. AA8090 aluminum alloy is one of the materials used in aero industries for aircraft construction because of its weight reduction ability. However, the AA8090 alloy has a drawback such as low wear resistance that affects the life time of material; hence, it should be addressed. The purpose of this investigation is to improve the wear resistance of AA8090 alloy.

In this investigation, AA8090 aluminum alloy metal matrix composite was fabricated using different types of carbide nanoparticles such as vanadium carbide (VC), Cr₃C₂ and Mo₂C by stir casting method and tribological and mechanical behaviors were studied.

Mechanical studies showed that the S1 sample displayed the maximum hardness of 142 HV and maximum tensile strength of 857 MPa because of the inclusion of hard VC particles. Tribological studies revealed that S1 sample showed high performance. A least wear rate of 0.003915 × 10^–3 mm³/m was noted for S1 sample, which is 71% lower than the wear rate of S0 sample. Further, a least mass loss and lower coefficient of friction of 0.00152 g and 0.2, respectively, were observed for S1 sample because of its high hardness and high wear resistance because of the stuffing of high-hardness VC particles. Hence, it is concluded from this study that S1 sample, i.e. AA8090/VC, could be a better candidate for aerospace applications as it showed good tribological and mechanical properties.

To the best of the authors’ knowledge, this work is original and novel in the field of metal matrix composite which deals with the effect of hybridization on the wear performance of the aluminum alloy composites.

The paper reports a study of the behaviour of on‐line searchers in looking for the answers to set questions. The work was carried out with a view to learning more about the way actual searches are conducted, so that instructions to users can be given to optimize the generation of references. The study suggests that developments in user education would be made considerably easier by some rationalization among file producers and systems, especially in spelling, vocabulary, basic commands and indexing philosophy.

The purpose of this paper is to outline some key aspects such as material systems used, phenomenological and statistical process modeling, techniques applied to monitor the process and optimization approaches reported. All these need to be taken into account for the ongoing development of the SLM technique, particularly in health care applications. The outcomes from this review allow not only to summarize the main features of the process but also to collect a considerable amount of investigation effort so far achieved by the researcher community.

This paper reviews four significant areas of the selective laser melting (SLM) process of metallic systems within the scope of medical devices as follows: established and novel materials used, process modeling, process tracking and quality evaluation, and finally, the attempts for optimizing some process features such as surface roughness, porosity and mechanical properties. All the consulted literature has been highly detailed and discussed to understand the current and existing research gaps.

With this review, there is a prevailing need for further investigation on copper alloys, particularly when conformal cooling, antibacterial and antiviral properties are sought after. Moreover, artificial intelligence techniques for modeling and optimizing the SLM process parameters are still at a poor application level in this field. Furthermore, plenty of research work needs to be done to improve the existent online monitoring techniques.

This review is limited only to the materials, models, monitoring methods, and optimization approaches reported on the SLM process for metallic systems, particularly those found in the health care arena.

SLM is a widely used metal additive manufacturing process due to the possibility of elaborating complex and customized tridimensional parts or components. It is corroborated that SLM produces minimal amounts of waste and enables optimal designs that allow considerable environmental advantages and promotes sustainability.

The key perspectives about the applications of novel materials in the field of medicine are proposed.

The investigations about SLM contain an increasing amount of knowledge, motivated by the growing interest of the scientific community in this relatively young manufacturing process. This study can be seen as a compilation of relevant researches and findings in the field of the metal printing process.

Friction stir welding (FSW) butt-joining involving the use of a dissimilar filler metal insert between the retreating and advancing portions of the workpiece is investigated computationally using a combined Eulerian-Lagrangian (CEL) finite element analysis (FEA). The emphasis of the computational analysis was placed on the understanding of the inter-material mixing and weld-flaw formation during a dissimilar-material FSW process. The paper aims to discuss these issues.

The FEA employed is of a two-way thermo-mechanical character (i.e. frictional-sliding/plastic-work dissipation was taken to act as a heat source in the energy conservation equation), while temperature is allowed to affect mechanical aspects of the model through temperature-dependent material properties. Within the analysis, the workpiece and the filler-metal insert are treated as different materials within the Eulerian subdomain, while the tool was treated as a conventional Lagrangian subdomain. The use of the CEL formulation within the workpiece insert helped avoid numerical difficulties associated with excessive Lagrangian element distortion.

The results obtained revealed that, in order to obtain flaw-free FSW joints with properly mixed filler and base materials, process parameters including the location of the tool relative to the centerline of the weld must be selected judiciously.

To the authors’ knowledge, the present work is the first reported attempt to simulate FSW of dissimilar materials.

The purpose of this paper is to obtain high-temperature-resistant material with high density and to conduct microstructural investigations of 3D-printed Ni-based alloy 713C specimens.

High-density specimens of Ni-based alloy 713C were obtained by the optimizing selective laser melting (SLM) process parameters and an X-ray diffraction (XRD) analysis confirmed the occurrence of γ and γ′ phases and the presence of carbides in the SLM-manufactured Ni-based alloy 713C. The analysis of electron backscatter diffraction (EBSD) studies suggested a preferred 〈100〉 direction orientation and low angle misorientation for the SLM specimens.

The high-density specimens of Ni-based alloy 713C were obtained by the optimized SLM process parameters. XRD analysis confirmed the presence of γ and γ′ phases and carbides in the SLM-manufactured Ni-based alloy 713C. Analysis of EBSD studies suggested a preferred 〈100〉 direction orientation and low angle misorientation for the SLM specimen.

In this study, 3D-printed Ni-based alloy 713C with a high density of 99% was obtained for the first time, to the best of the authors’ knowledge.

The purpose of this paper is to determine the use of BLA along with SiC as economical reinforcements to enhance the mechanical behavior of hybrid composite. The purpose of this research is the development of cost-effective aluminum hybrid metal matrix composites.

The present research work investigation evaluated the mechanical properties of Al-4.5%Cu alloy, Al-4.5Cu/10SiC, Al-4.5Cu/10SiC/2BLA and Al-4.5Cu/10SiC/4BLA composites by the Stir casting method. The fabricated composites were analyzed using optical microscopy (OM), scanning electron microscopy (SEM), and hardness and tensile test.

The microstructure modification with the addition of reinforcement particles in the matrix alloy and clear interface in between matrix and particles are observed. The density of the composite increased with the addition of SiC and decreased with the addition of BLA in comparison with that of matrix alloy. The hardness and tensile strength of the single-reinforced composite and hybrid composites improved with the addition of reinforcement particles. The strengthening of composites was due to load-bearing capacity of reinforcement particles over the matrix alloy and increased dislocation density of composites materials. The tensile failure mechanism of the composites is reveled with SEM analysis.

The papers reports the development of cost-effective and light weight aluminum hybrid composites with remarkable enhancement in the mechanical and tribological properties with the addition of BLA as economical reinforcement along with SiC.

The density, hardness and tensile values of fabricated aluminium composites were presented in this paper for the use in the engineering applications where the weight and cost are consider as a primary factors.

The purpose of this paper is to outline the feasibility of using the electrospark welding (ESW) process to free‐form metallic components with nanostructured or amorphous microstructures.

ESW was used to deposit amorphous and nanostructure coatings for high‐wear resistance applications. The ESW process was also used to freeform three‐dimensional objects via multiple deposition passes. The near‐net shape capability is interesting as it significantly reduces the post‐processing operations.

This paper demonstrates that it is possible and economically feasible to produce components possessing metastable structures, i.e. nano or amorphous, using the ESW process.

The ESW process possesses the ability to manufacture advanced materials and can pattern surfaces to provide appropriate functionality with respect to the service environment.

This paper represents a summary of the capabilities of ESW to fabricate advanced materials and is based on the achievements of our laboratory. In particular, results on ESW of amorphous materials and the ability to produce coatings with second phase particles refined to this extent have not been achieved using other manufacturing methods.