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Mg-Al powder mixture was used to manufacture Mg-Al alloy by laser powder bed fusion (LPBF) process. This study aims to investigate the influence of initial Al content and processing parameters on the formability, microstructure and consequent mechanical properties of the laser powder bed fused (LPBFed) component.

In this study, Al powder with different weight ratio ranged from 3 to 9 per cent was mixed with pure Mg powder, and the powder mixture was processed using different LPBF parameters. Microstructure and compressive properties of the LPBFed components were examined.

It was found that the presence of Al significantly modified the microstructure and improved the mechanical properties of the LPBFed components. Higher volume of ß-Al12Mg17 precipitates was produced at higher initial Al content and higher laser energy density. For this reason, the a-Mg was significantly refined and the compressive strength was improved. The highest yield compressive strength achieved was 279 MPa when using Mg-9 Wt. % Al mixture.

This work demonstrates that LPBF of Mg-Al powder mixture was a viable way to additively manufacture Mg-Al alloy. Both Al content and processing parameters can be modified to control the microstructure and mechanical properties of the LPBFed components.

This study aims to focus on experimenting the performance of aluminum (Al) powder mixed electric discharge machining (PMEDM) of two different materials viz plastic mould die steel (AISI P20) and nickel-based super alloy (Nimonic 75). This experimental study also focuses on using three different tool materials such as copper, brass and tungsten to analyze their influence on the process output. These materials find many uses in industrial as well as aerospace applications. The performance measures considered in this work are material removal rate (MRR), tool wear rate (TWR) and surface roughness (SR).

The experimental design used in this work is based on Taguchi’s L18 orthogonal array. Besides considering work and tool material as one of the process variables, other process variables are peak current (I_p), pulse on time (T_on) and concentration of powder (C_p). The analysis of variance (ANOVA) is performed on the experimental data to determine the significant variables that influence the output.

It is found that copper produced maximum MRR and brass tool exhibited higher TWR. However, the surface finish of the machined work piece was very much improved by using the brass tool. Though the performance of tungsten tool lies between the above two tool materials, it showed very little wear during EDM with or without the addition of Al powder.

The experimental investigation of PMEDM of nickel-based super alloy (Nimonic 75) has not been attempted before. Besides that, the study on the influence of tungsten tool on the performance of EDM is also very limited.

The purpose of this paper is to investigate the performance of powder-mixed electric discharge machining (PMEDM) using three different powders which are aluminium (Al), silicon carbide (SiC) and aluminium oxide (Al₂O₃). Besides that, the influence of different tool materials was also studied in this experimental investigation. Hence, the work material selected for this purpose was AISI P20 steel and tool materials were copper, brass and tungsten. The performance measures considered in this work were material removal rate (MRR), tool wear rate and radial over cut (ROC).

The process variables considered in this study were powder types, powder concentration, tool materials, peak current and pulse on time. The experimental design, based on Taguchi’s L₂₇ orthogonal array, was adopted to conduct experiments. Significant parameters were identified by performing the analysis of variance on the experimental data.

Based on the analysis of results, it was observed that copper tool combined with Al powder produced maximum MRR (58.35 mm³/min). Similarly, the Al₂O₃ powder combined with tungsten tool has resulted least ROC (0.04865 mm). It was also observed that wear rate of tungsten tool was very low (0.0145 mm³/min).

The experimental investigation of PMEDM involving three different powders (Al, SiC and Al₂O₃) was not attempted before. Moreover, the study of influence of different tool materials (Cu, brass and W) together with the different powders on the electric discharge machining performance was very limited.

The spent electroless copper bath is deactivated at the overflow by the automatic addition of hydrogen peroxide (H2O2) to prevent copper from plating out in the drain lines, causing the lines to become blocked. Caustic (NaOH) and formaldehyde (HCHO) are then added to the deactivated electroless copper solution in a batch treatment process. Powdered aluminium or aluminium fines are added to precipitate out the copper as metallic copper. The copper concentration (<1 ppm) can be made stable for several days if necessary. The metallic copper is filtered out and salvaged. The mother liquor is neutralised (pH 6·5–9·0) and discharged. United States patent applied for, 07–345865.

To improve the electrochemical corrosion resistance of cold sprayed Al coating.

A cold sprayed aluminum (Al) coating fabricated on S355 structural steel was oxidized using a micro arc oxidation (MAO). The electrochemical corrosion and impedance spectroscopy were tested to investigate its corrosion performance.

The MAO film is primarily α-Al₂O₃ and γ-Al₂O₃, which increases its density and surface quality. The corrosion potential is positively shifted by 0.2 V, and the electrochemical impedance is significantly increased.

A cold sprayed Al coating on S355 steel was first oxidized using a MAO. The effects of MAO on the microstructure of Al coating were investigated to analyze its electrochemical corrosion behavior.

This paper aims to fabricate nickel-aluminum (Ni-Al)-based self-lubricating composite coating on aluminum (Al) alloy by mechanical milling (MM).

A new carrier transport (CT) way was designed to solve the slippage fracture of the coating due to silver (Ag) accumulation (Ag powders were cold welded with nickel [Ni] powders by MM in advance to avoid accumulation, then Al powder and samples were added to fabricate the coating).

Microstructure analysis reveals that the solid lubricant Ag exists as particles in the composite coating via CT technique, which is different from the typical morphology (strip-type) of Ag tailored by normal methods. The unique granular form of Ag can effectively avoid the gliding fracture of the coating, thus forming an efficacious lubrication film on the worn surface, which is responsible for the excellent tribological properties of the coating.

Most of the papers reported that coatings synthesized by MM mainly concentrated on hard coatings, but the fabrication of self-lubricating coatings have not yet reported.

The uniform dispersion of solid lubricant Ag can effectively solves a fatal problem that the fracture failure of coating triggered by the Ag accumulation. This experiment provides a novel method for preparation of self-lubricating coating by MM.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-01-2020-0030

This study aims to highlights the mechanical, thermal and melting behavior compatibility of aluminum (Al)-reinforced polyamide (PA) 6/acrylonitrile butadiene styrene (ABS)-based functional prototypes prepared using fused deposition modeling (FDM) from the friction welding point of view. Previous studies have highlighted the use of metallic/non-metallic fillers in polymer matrix for preparations of mechanically improved FDM feedstock filaments and functional prototypes. But hitherto, very less has been reported on fabrication of functional prototypes which fulfill the compatibility of two polymers for joining/welding-based applications. The compatibility of two dissimilar polymers enables the friction welding for maintenance applications.

The twin screw extrusion process has been used for mechanical mixing of metallic reinforcement in polymer matrix, and final blend of reinforced polymers in the form of extruded feed stock filament has been used on FDM for printing of functional prototypes (for friction welding). The methodology involves melt flow index (MFI) investigations, differential scanning calorimetry (DSC) investigations for thermal properties, tensile and hardness testing for mechanical properties and photo micrographic investigations for metallurgical properties on extruded samples.

It was observed that the reinforced ABS and PA6 polymers have better compatibility in the terms of similar melt flow, thermal properties and can lead to the better joint efficiency with friction welding.

In the present work composite feed stock filament composed of ABS and PA6 with reinforcement of Al powder has been successfully developed for preparation of functional prototype in friction welding applications.

To introduce an innovative method for the design of supporting elements to be applied to the free‐form components during the dimensional control.

This paper shows an innovative procedure based on reverse engineering and rapid prototyping techniques for the realization of fixtures fitting the geometry of free‐form elements. The application of the procedure have been made on a sheet metal free‐form element. After the design and manufacturing of the supporting elements, some uniformly distributed measurements have been made on the sheet metal component. A coordinate measuring machine (CMM) has been used in order to get dimensional information and to give the IT class location of the component.

The use of the CMMs for the dimensional control of the production elements requires the availability of an adequate supporting system above all if the control concerns free‐form components with complex forms. This influences considerably the final quality of the measurements mainly if the control concerns free‐form components with complex forms, not bound to classic geometric entities. The supporting systems commonly used foresee the utilization of standard elements (clamps, magnets, suction cups and plates and others) ideal for the parts with regular geometry but that can cause inconveniences if applied to free‐form elements and long times for the part supporting. The supporting elements of our paper fit to the geometry of free‐form component.

For the production of the supporting elements, the chosen technique has been the selective laser sintering with the use of the Pa‐Al powders (alumide). This material has a limited mechanical resistance such to guarantee a control up to 500 parts. For this reason, in a future research we would produce these fixtures using sintered metal materials.

The possibility to guarantee a correct dimensional control in the case of free form components using fixtures that fit to the geometry of free form components.

The paper shows an innovative procedure to get fixturing elements that fit to the geometry of free‐form component and provide stability and immobility to the component during the inspection phase.

The purpose of this study is to investigate and evaluate the impact of varying proportions of reinforcement on the mechanical properties of a modified Al₂O₃-LM6 cast composite under self-pouring temperature conditions. This study aims to determine the optimal mixture proportion of fine powders of Al, Si and xAl₂O₃ (with x values of 2%, 3% and 4%) through the application of design of experiment (DoE) and statistical analysis using the Minitab software. This study also involved evaluating the microstructural estimation and other physical properties of the cast composite to understand the combined effect of the reinforcement proportion on the material’s properties.

The researchers initially mixed the powders through ball milling and then compacted the moisture-free powder mix in a closed steel die. The resulting preforms were heated at the self-pouring temperature in an inert environment to fabricate the final cast composite. By applying DoE and performing an analysis of variance (ANOVA), the researchers sought to optimize the mixture proportion that would yield the best mechanical properties.

The experimental results indicated that a mixture combination of 83.5% Al blended with 12.5% Si and 4% Al₂O₃ led to the greatest improvement in mechanical properties, specifically in terms of increased density, hardness and impact strength. The ANOVA further supported the interaction effect of each processing parameter on the observed results. The results of this study offer valuable insights for the fabrication of modified Al₂O₃-LM6 cast composites under self-pouring temperature conditions. The identified optimal mixture proportion provides guidance for manufacturing processes and material selection to achieve improved mechanical properties in similar applications.

This study focuses on a specific composite material consisting of modified Al₂O₃ and LM6. Although Al₂O₃ and LM6 have been studied individually in various contexts, the combination of these materials and their impact on mechanical properties under self-pouring temperature conditions is a novel aspect of this research. The researchers use DoE methodology, along with statistical analysis using Minitab software, to optimize the mixture proportion and analyze the data. This systematic approach allows for a comprehensive exploration of the parameter space and the identification of significant factors that influence the mechanical properties of the composite.

The purpose of this paper is to study the effects of particle size distribution, component ratio, particle packing arrangement, and chemical constitution on the laser sintering behaviour of blended hypoeutectic Al‐Si powders.

A range of bimodal and trimodal powder blends were created through mixing Al‐12Si and pure aluminium powder. The powder blends were then processed using selective laser sintering to investigate the effect of alloy composition, powder particle size and bed density on densification and microstructural evolution.

For all of the powder blends the sintered density increases with the specific laser energy input until a saturation level is reached. Beyond this saturation level no further increase in sintered density is obtained for an increase in specific laser energy input. However, the peak density achieved for a given blend varied significantly with the chemical constitution of the alloy, peaking at approximately 9 wt% Si. The tap density of the raw powder mixture (assumed to be representative of bed density) was also a significant factor.

This is the first study to consider the usefulness of silicon as an alloying element in aluminium alloys to be processed by selective laser sintering. In addition the paper outlines the key factors in optimising processing parameters and powder properties in order to attain sound sinterability for direct laser sintered parts.