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1

A validated framework for the development of low-cost aluminum dies through rapid investment casting

Shehbaz Muhammad, Sajid Muhammad, Ali Muhammad Asad, Ahmad Wasim

Advances in Science and Technology. Research Journal

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2026

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Vol. 20, no. 1

104–-120

EN

The rising demand for agile, economical, and scalable manufacturing has driven the need for innovative approaches in tool and die development. Aluminum has emerged as a promising alternative to traditional die materials due to its low density, excellent castability, thermal conductivity, machinability, and recyclability. This study proposes and validates a structured framework for the development of low-cost aluminum dies using Rapid Investment Casting (RIC). The framework, grounded in an extensive review of existing practices, is implemented through a real-world case study focused on the development of a die for an automotive door handle. A CAD model was designed with a 3%-dimensional tolerance, and the die was fabricated using LM30 aluminum alloy via RIC. The die was then tested using polypropylene (PP) in an injection molding process to evaluate its dimensional accuracy and surface roughness. Results revealed that in contrast to certain features, which exhibited strong dimensional consistency—such as the circle diameter along the large pin, front lengths, and upper slope depth (with deviations within ±0.1 mm to ±0.2 mm) some geometries, particularly sloped features, showed notable discrepancies. Small slope length 1 demonstrated a significant reduction of 0.66 mm during casting, likely due to angular mold erosion or material pullback. Additionally, the small and large mounting pin lengths, handle length, and small slope length 1 recorded the highest dimensional deviations. Despite these variations, the aluminum die achieved a surface finish near the industrial standard of 3.2 µm, while the molded PP part exhibited improved surface quality. Economic considerations reveal the saving of time (~7 to 3 weeks) and cost ($720 to $180). The results demonstrate that the proposed RIC-based framework provides a cost-effective, efficient, and flexible solution for producing customized or low-volume dies, offering reduced tooling costs and faster production cycles while meeting the industry standards.

2

Pentamer fragments as green corrosion inhibitors of Al, Fe and Cu metals

Abu-Sbeih Khaleel A., Al-Mazaideh Ghassab

Ochrona przed Korozją

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2025

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nr 4

107--113

EN

Chitosan oligomers can act as green corrosion inhibitors for metals. The effect of the location of the acetyl group in the oligomer on its ability to inhibit the corrosion of the metals Al, Fe, and Cu was studied employing DFT calculations using the B3LYP functional and the 6-31G* (d,p) basis set. Various quantum, polarizability, and reactivity parameters were calculated and used to assess the relative capabilities of the oligomers to inhibit the corrosion of the metals. All of the pentamers were found to have spontaneous chemisorption on the surfaces of the metals. PAG1, the pentamer which has the acetyl group at the end of the chain, had the best reactivity and polarizability parameters of the three pentamers studied, thus making it the most effective corrosion inhibitor of the oligomers.

PL

Oligomery chitozanu mogą działać jako zielone inhibitory korozji metali. Wpływ położenia grupy acetylowej w oligomerze na jego zdolność do hamowania korozji metali Al, Fe i Cu zbadano za pomocą obliczeń DFT z wykorzystaniem funkcjonału B3LYP i zestawu funkcji bazowych 6-31G* (d,p). Różne parametry kwantowe, polaryzowalności i reaktywności zostały obliczone i wykorzystane do oceny względnych zdolności oligomerów do hamowania korozji metali. Stwierdzono, że wszystkie pentamery wykazują spontaniczną chemisorpcję na powierzchniach metali. PAG1, który ma grupę acetylową na końcu łańcucha, charakteryzował się najlepszymi parametrami reaktywności i polaryzowalności spośród trzech analizowanych pentamerów, co czyni go najskuteczniejszym inhibitorem korozji w grupie badanych oligomerów.

3

The application of numerical simulations to analyze the forward extrusion process along with the verification of results and tuning of the numerical model

Hawryluk Marek, Dudkiewicz Łukasz, Marzec Jan, Tkocz Roger, Borowski Jacek, Ficak Grzegorz, Jóźwiak Bartosz, Ziemba Jacek

Computer Methods in Materials Science

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2025

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Vol. 25, No. 2

27--39

EN

The paper presents the application of numerical simulations based on the Finite Element Method (FEM) for analyzing and optimizing the extrusion processes of aluminum and lead. These processes are efficient methods for manufacturing critical machine parts and metal components, ensuring excellent mechanical properties. A detailed analysis was conducted on the numerical modeling of the impact of die taper angles on strain distribution and forming forces during co-extrusion. The study found that a 45-degree angle provides optimal deformation conditions, minimizing extrusion forces and reducing the formation of dead zones compared to a 90-degree angle. Numerical simulations, supplemented by technological trials under semi-industrial conditions and image analysis involving the deformation of the coordinate grid, provided key insights into a material flow, strain distribution, and force parameters. The results emphasize the importance of validating numerical models with semi-industrial experiments to ensure accuracy and reliability, as assuming constant tribological conditions may not reflect actual process conditions, including the formation of dead zones for angles greater than 45°. It was only through a thorough analysis of the actual process and the introduction of variable friction coefficients for individual tools that a dead zone was achieved in the modelling. The findings from this research can serve as the foundation for further optimization and adaptation of technological processes, aiming to further enhance extrusion processes through the use of numerical simulations.

4

Microstructure and Wear Properties of Aluminum Metal Matrix Composite (Al6061-B4C) Fabricated by Stir Casting Process

Choi Sun Kyu, Seo Bosung, Kang Jang Won, Kim Dae Ha, Park Hyung-Ki, Park Kwangsuk

Archives of Metallurgy and Materials

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2025

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Vol. 70, iss. 2

601--607

EN

Mechanical properties of Al6061-B4C composites fabricated by stir casting method, even though over 120 µm B4C reinforcement was used, was evaluated. The big reinforcement also could exert an impact on mechanical properties such as hardness and wear resistance. The presence of the harder particles dispersed in Al6061 increased hardness, which would in turn affect wear performance. The high hardness reduced the contact area between the sample and ball and thus, leaded to the reduced coefficient of friction (COF) and wear loss. The Al6061-12 wt.% B4C composite showed the best wear resistance, resulting in the narrowest and shallowest scar. The higher hardness of the Al6061-12 wt.% B4C composite changed wear mechanism changed from adhesive to abrasive wear so that the best wear resistance could be achieved.

5

Characterization of EN-AW-6061-O–graphite nanoflake composites for enhanced mechanical properties using multi-pass friction stir processing

Patil Namdev Ashok, Pedapati Srinivasa Rao, Kakkeri Shrishail, Pedapati Santoshi

Advances in Materials Science

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2025

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Vol. 25, nr 3(85)

5--17

EN

In this study, graphite (Gr) nano flakes dispersion with increasing number of passes (1, 2, and 3) inside the resultant aluminium ENAW-6061-O-Gr composites using Friction Stir Processing (FSP) has been accomplished successfully. The objectives were to embed the Gr nanoflakes inside ENAW-6061-O-Gr composites, investigate the effect of number of FSP passes on the mechanical properties of aluminium 6061/graphite composites. The ENAW-6061-O-Gr composite samples were evaluated with tensile tests and elemental analysis through SEM with EDX and mapping. The dispersion and presence of graphite particles is confirmed. Multi-pass FSP improved the tensile strength of the ENAW-6061-O-Gr composites. The UTS of C3-Composite processed with three passes is 153.65 MPa, that is 24% of improvement compared to the unreinforced aluminium ENAW-6061-O base metal alloy.

6

Wpływ zawartości grafitu na właściwości mechaniczne warstw hybrydowych Ni-P/Si3N4/grafit osadzonych na stopie AW-7075 metodą redukcji chemicznej

Czapczyk Kazimierz

Przemysł Chemiczny

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2024

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T. 103, nr 1

86--92

PL

Przedstawiono wpływ obecności grafitu jako fazy dyspersyjnej na właściwości mechaniczne warstw hybrydowych Ni-P/Si₃N₄/grafit, które osadzono metodą redukcji chemicznej na stopie glinu AW-7075. Wykonano badania morfologii powierzchni warstw metodą mikroskopii świetlnej i skaningowej. Dalszą część pracy stanowiły badania mechaniczne, czyli pomiary mikrotwardości warstw oraz ich adhezji do aluminiowego podłoża, a także analizy wpływu obecności grafitu na podstawowe właściwości materiału powłokowego. Zbadano próbki ze stopu AW-7075, na których osadzono metodą bezprądową powłoki hybrydowe i porównawczo nanokompozytowe o różnym składzie chemicznym, modyfikowanym zawartością faz dyspersyjnych.

EN

The mech. and adhesive properties of Ni-P/Si₃N₄ and Ni-P/Si₃N₄/graphite coatings deposited using the electroless method on the AW-7075 Al alloy were compared. Coatings with different chem. compns., modified by the content of dispersion phases (Si₃N₄ and graphite), were used. Microhardness and adhesion of the layers to the Al substrate were measured. The impact of the presence of graphite on the basic properties of the coating material was analyzed. The surface morphol. of the layers was examined using light microscopy and SEM. The incorporation of Si₃N₄ and graphite into the coating material resulted in a several-fold increase in the microhardness of the surface layer compared to the Al alloy.

7

Use of Nano Co-Ni-Mn Composite and Aluminum for Removal of Artificial Anionic Dye Congo Red by Combined System

Jasim Reman A., Salman Rasha H.

Ecological Engineering & Environmental Technology

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2024

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Vol. 25, iss. 7

133--149

EN

The removal of congo red (CR) is a critical issue in contemporary textile industry wastewater treatment. The current study introduces a combined electrochemical process of electrocoagulation (EC) and electro-oxidation (EO) to address the elimination of this dye. Moreover, it discusses the formation of a triple composite of Co, Mn, and Ni oxides by depositing fixed salt ratios (1:1:1) of these oxides in an electrolysis cell at a constant current density of 25 mA/cm2 . The deposition ended within 3 hours at room temperature. X-ray diffractometer (XRD), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and energy dispersive X-ray (EDX) characterized the structural and surface morphology of the multi-oxide sediment. Marvelously, the deposition has simultaneously occurred on both anodic and cathodic graphite electrodes. These electrodes besides aluminum (Al) are employed as anodes in the EC-EO system, and the results were optimized by response surface methodology (RSM). The optimum operating conditions were a current density of 6 mA/cm2 , pH = 7, and NaCl of 0.26 g/L. The results showed that the combined system eliminated more than 99.91% of the congo red dye with a removal of chemical oxygen demand (COD) of around 97% with 1.64 kWh/kg of dye of the consumed energy. At low current density, the current delivered for the composite anode was more than for the Al anode with the same surface area. On top of this superiority, the EC-EO scenario is a practical hybrid process to remove CR in an environmentally friendly pathway.

8

Synthesis and Characterization of Novel Aluminum Composites: A Compo-Casting Approach with ZrO2, Al2O3, and SiC

Farahany S., Hamdani M. K., Salehloo M. R., Krol M., Cheraghali E.

Archives of Foundry Engineering

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2024

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Vol. 24, iss. 2

88--97

EN

The present study evaluates the microstructural features, mechanical properties, and wear characteristics of the newly developed hybrid composite of A356/ZrO2/Al2O3/SiC produced by compo-casting at 605±5 °C, 600 rpm for 15 minutes with less than 30% solid fraction in which Bi and Sn were added separately to the matrix before introducing reinforcements. FESEM micrographs and corresponding EDS illustrated the successful incorporation of particles in the matrix. Fine particles of ZrO2 were observed close to the coarse Al2O3, and SiC particles, along with Bi and Sn elements, were detected at the eutectic evolution region. The A356+Bi/Al2O3+ZrO2+SiC hybrid composite exhibited the lowest specific wear rate (1.642 ×10-7cm3/Nm) and friction coefficient (0.31) under applied loads of 5, 10, and 20 N, in line with the highest hardness (73.4 HBN). Analysis of the worn surfaces revealed that the wear mechanism is mostly adhesive in all synthesized composites, which changed to the combination of adhesive and abrasive mode in the case containing Bi and SiC. Inserting Bi not only leads to the refinement of eutectic Si but also enhances the adhesion between the matrix/particles and improves lubricity. This, in turn, reduces the wear rate and coefficient of friction, ultimately improving the performance of the hybrid composite.

9

Removal of microplastics by electrocoagulation

Pilco-Nuñez Alex, Hinostroza-Antonio Edilberto, Diaz-Bravo Pablo, Palacios-Salvador Wendy, Solis-Toledo Richard, Baldeon-Romero Jhanover

Archives of Environmental Protection

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2024

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Vol. 50, no. 4

64–-71

EN

With the gradual increase of microplastics in water bodies, it is essential to understand the current treatment processes for their removal. This study aims to investigate the removal of microplastics in synthetic solution by electrocoagulation (EC). The effects of electrode type, contact time (min), agitation speed (rpm) and current density (A/m²) were evaluated using a fractional factorial design. The results showed that the aluminum anode achieved a higher removal of microplastics than the iron anode, reaching 98.04% removal with the aluminum operational configuration within 15 min at 70 rpm and a current density of 20 A/m². A high correlation between the predicted and observed removal was evidenced, with values of R²= 0.99 and adjusted R²= 0.98, indicating a good agreement between the model and the experimental data, confirming the validity and feasibility of the adopted linear model. This study demonstrates that the electrocoagulation process has a great potential for the removal of microplastics.

10

Influence of aluminum alloys surface treatment on the durability of glued joints

Kowalik Joanna, Tworek Magdalena, Smaruj Michał

Polimery

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2023

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Vol. 68, nr 10

523--529

EN

The aim of the work was to analyze the method of preparing the aluminum surface in terms of the functional properties of glued joints with the use of one-component polyurethane adhesive. Six methods of surface treatment of EN AW-5251 aluminum alloy were tested. In addition, changes in the shear strength of adhesive joints after environmental exposure were determined. The best surface preparation processes were atmospheric plasma and anodizing.

PL

Celem pracy była analiza sposobu przygotowania powierzchni aluminium pod kątem właściwości użytkowych połączeń klejonych z zastosowaniem jednoskładnikowego kleju poliuretanowego. Zbadano sześć metod obróbki powierzchni stopu aluminium EN AW-5251. Ponadto określono zmiany wytrzymałości połączeń klejonych na ścinanie po ekspozycji środowiskowej. Najlepszym sposobem przygotowania powierzchni była plazma atmosferyczna i anodowanie.

11

Optimization of Response Surface Methodology for Removal of Cadmium Ions from Wastewater using Low Cost Materials

Mohammed Risalah A., Abdulhasan Maryam Jawad, Raheem Shahad A., Alwared Abeer I., Mohammed Noor A., Kadhim Rand Fadhil, Al-Bayati Alaa Dhari Jawad

Journal of Ecological Engineering

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2023

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Vol. 24, nr 8

146--156

EN

This study goal to the ability of using low cost materials representing thermestone and aluminum solid wastes in water filtration by using a pilot plant constructed in wastewater treatment plant to remove cadmium ions (Cd(II)). Response Surface Methodology (RSM) used to optimize the optimal parameters that affecting the performance of filter units, these parameters are time, Cd(II) concentration, and filtration rate. These optimized parameters were 9 hr., 5 ppm, 10 l/hr. with removal efficiency of Cd(II) for A-Filter, T-Filter, S-Filter, and A-T-S-Filter was 94%, 95%, 86.8% and 90%, respectively. The result shows that the T-filter has higher cadmium removal efficiency than A-filter, S-filter and S-T-A- filter. While A-filter has a higher removal efficiency of cadmium than the S-filter and S-T-A- filter. While the S-T-A- filter has higher efficiency than S- filter. The result obtained from RSM was good Agreement with the result of experiments. As a result, the optimized process in this paper can be widely utilized with high removal ratio of Cd(II) ions from wastewater samples.

12

Research on New Al-Ag-Mo Alloys Dedicated to Wire Applications in Overhead Power Lines

Grzebinoga Justyna, Mamala Andrzej, Ściężor Wojciech, Kowal Radosław

Journal of Casting & Materials Engineering

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2023

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Vol. 7, no. 1

9--14

EN

The latest research work in the field of electric power systems focuses on the development of new wire materials which will allow the increase of the transmission capacity of power lines currently in use. The reason for this research was the often limited possibilities of continuous and failure-free transmission of electricity. In this paper, the authors present research on a new aluminium-based alloy dedicated for use as a conductive braid in the HTLS cable group. There are many technical solutions for this group of cables on the market, although they are solutions with a number of disadvantages, ranging from their high price, various operational shortcomings, complicated installation techniques, and ending with the risk of monopolistic practices, which is related to the inability to attract several competitive suppliers. The main aim of the research was to develop a new alloy based on aluminium with the addition of silver and molybdenum dedicated for use in special overhead power cables. Experimental research on new materials focused on obtaining the necessary knowledge to produce an overhead wire from these alloys with higher current carrying capacity in relation to the currently used conventional wire materials based on aluminium.

13

Effect of Aluminum Content on the Combustion Performance of HTPB/AP/Al Propellants under High Combustion Pressure

Han Jin-chao, Hu Song-qi, Chu Cheng-long, Liu Lin-lin

Central European Journal of Energetic Materials

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2023

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Vol. 20, no. 1

14--35

EN

Combustion mechanisms of propellants under high combustion pressure are extremely important for the development of high-pressure solid rocket motors. The combustion characteristics of three HTPB propellants prepared with an aluminum content of 1%, 10%, and 18% were evaluated in this study by analyzing the extinguished propellant surface, the combustion flame, and the temperature profile in the combustion pressure range of 12-30 MPa. The results showed that the burning surface temperature of the three propellants increased from 425 to 535 and to 643 ℃ as the aluminum content was increased from 1% to 18%, resulting in a faster thermal decomposition rate of the binder than the thermal decomposition rate of the AP particles. Consequently, the morphology of the extinguished propellant surface evolved from concave into convex, and the higher the aluminum content, the more obvious became the convex morphology. The combustion flame height of the three propellants showed a downward trend when the combustion pressure was increased from 12 to 18 MPa, enhancing the heat feedback to the burning surface. The burning surface temperature of the three samples increased by 75, 105 and 189 ℃, respectively, with the increase in combustion pressure, resulting in a more distinct degree of concave and convex morphology of the extinguished propellant surface. In addition, this demonstrated that the local heat and mass transfer might play a dominant role under high pressures.

14

Research on the post-weld explosive hardening of AA7075-T651 friction stir welded butt joints

Kosturek Robert, Lewczuk Rafał, Torzewski Janusz, Wachowski Marcin, Słabik Piotr, Maranda Andrzej

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2023

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Vol. 71, nr 4

art. no. e145685

EN

In this paper, the post-weld explosive hardening of a 5 mm AA7075-T651 plate welded via FSW was performed. To investigate the possibility of increasing FSW joint mechanical properties, the welded plate was explosively treated with four various explosive materials (ammonal, emulsion explosive, FOX-7, and PBX) in two different hardening systems. As part of the investigation, the observations of the surface and macrostructure of the treated plates were described. The obtained microhardness distribution allowed us to register the increase in hardness of the SZ up to 6%, but no increase in hardness of the LHZ was reported. In most cases, the influence of explosive treatment on the mechanical properties of the welded joint was disadvantageous as ultimate tensile strength and ductility were reduced. The only positive effect which was observed is the increase in the value of yield strength up to 27% corresponding to 77 MPa, achieved by explosive materials with detonation velocity below 3000 m/s.

15

Surface Alloying of Cupronickel Alloy with Aluminum using Tungsten Inert Gas Process

Koeini Fatemeh, Sohi Mahmoud Heydarzadeh, Pirayesh Parham

Archives of Metallurgy and Materials

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2023

|

Vol. 68, iss. 1

161--170

EN

Surface melting and alloying of Copper-Nickel (Cupronickel) alloy by preplacing aluminum powder and using tungsten inert gas process (TIG) in shielded atmosphere of argon gas were investigated. Surface melting resulted in the formation of a fairly porous dendritic microstructure. Surface alloying with aluminum resulted in the formation of Al2Cu and Al4Cu9 intermetallic compounds along with Cu-rich matrix and unstable martensitic structure. Surface melting reduced the hardness from 140 HV0.1 (substrate) to 70 HV0.1, mainly due to the loss of cold work effect of the initial substrate. On the other hand, surface alloyed zone showed a hardness of 300 HV0.1, mainly due to the formation of intermetallic compound. Tafel polarization results indicated improvement in corrosion resistance of cupronickel alloy after surface melting and alloying.

16

Temperature and Die Angular Effect on Tensile Strength, Hardness, Extrusion Load and Flow Stress in Aluminum 6063 Processed by Equal Channel Angular Extrusion Method

Azeez Temitayo M., Mudashiru Lateef O., Asafa Tesleem B., Akande Saheed, Ikumapayi Omolayo M., Kayode Joseph F., Uchegbu Ikenna D., Afolalu Sunday A.

Advances in Science and Technology. Research Journal

|

2023

|

Vol. 17, no. 1

346--353

EN

Developing aluminum with good mechanical properties like hardness, tensile strength, and normal flow stress, Equal Channel Angular Extrusion (ECAE) method has been suggested as a suitable metal forming process. The load applied and extrusion temperature normally infl uences the flow stress behavior in extruded products and de- termine their mechanical properties. Consequently, how these factors affect mechanical behavior and flow stress of Al 6063 processed by ECAE was examined in this study. Extrusion temperatures were 350°C, 425°C, and 500°C with die angles of 130°, 140°, and 150°. 5 mm/s of ram speed was applied. Each extrudate’s tensile strength and hardness were measured using a Universal Testing Machine and a Rockwell hardness tester. Samples with equal dimensions and properties were also modeled using the Qform software at the extended die angle and temperature for proper analysis of flow stress in the extrudates. According to experimental results, the temperature had a greater effect on the tensile strength and hardness of the billet than the die angle. The extrudates’ grains also became finer as the billet temperature rose. Simulation findings showed that higher billet temperature led to a decrease in the extrudates’ flow stress. The simulation also demonstrated that billet temperature had a greater impact on extrusion load than die angle, with a maximum extrusion load of 5.5 MN being attained at 350 °C.

17

Plasma welding of aluminum in an oxygen-free argon atmosphere

Klett Jan, Bongartz Benedict, Wolf Thomas, Hao Chentong, Maier Hans Jürgen, Hassel Thomas

Advances in Materials Science

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2023

|

Vol. 23, nr 1(75)

5--18

EN

Plasma welding is characterized by a high concentration of energy, which allows for high welding speed and leads to less distortion and residual stresses compared to conventional welding processes. Due to the local and controlled heat input, the process is suitable for sheet metal from ≈ 0.1 mm (micro plasma) up to ≈ 10 mm. In the case of aluminum and its alloys, the natural aluminum oxide layer on the metal surface limits the productivity of the plasma welding process. The electrically isolating and thermally insulating Al2O3 layer has a significantly higher melting point compared to the aluminum (Tm(Al2O3) = 2072 °C vs. Tm(Al) = 660 °C). The oxide layer hinders the formation of a stable arc and can even impede the joining formation. In order to remove the oxide layer and to produce quality welds with a DC process, it is necessary to weld with reverse polarity to use the principle of cathodic surface cleaning. However, this leads to increased electrode wear and increased penetration depth, which is not always desirable. In the study presented, the use of silane to reduce the oxygen content in the welding atmosphere as well as to remove the natural aluminum oxide layer on the metal surface was investigated. As previous studies have shown that the use of silane-doped plasma-gases is suitable for removing the superficial oxide layer on aluminum components, high-quality welded joints were expected. Quality welds with sufficient dilution were achieved using a transferred arc silane-doped helium plasma. In contrast, welding with an argon-silane mixture led to excessive pores formation. Additionally challenges to stabilize the arc process were identified and ramifications with respect to process optimization are discussed.

18

The role of the chemical composition of trivalent passivation bath for aluminum 5005A series in shaping the morphology of conversion coating and corrosion resistance

Gralak Eryk, Hoffman Adrianna, Winiarski Juliusz

Ochrona przed Korozją

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2022

|

nr 6

177--181

EN

5005A series aluminum samples were passivated to obtain a conversion coating based on Cr(III) compounds. It was shown that the corrosion resistance of galvanized aluminum in a bath containing both zirconium and cobalt compounds, measured in a 0.05 M NaCl solution, slightly increased compared to the corrosion resistance of aluminum as delivered, i.e. without conversion coating. In the case of galvanic treatment of aluminum in baths containing separately cobalt or zirconium compounds, a significant increase in corrosion resistance was achieved in relation to aluminum in the delivered condition. SEM analysis showed that in the presence of the simultaneous addition of zirconium and cobalt compounds, the most developed surface was created compared to the addition of only zirconium, where bright spheroidal precipitates occur locally. EDS analysis showed the presence of : C, O, Mg, Al and Si, small amounts of Cr, Zr, F on the surface of the aluminum covered with the Cr + Zr + HF conversion coating. During measurements with the use of the linear polarization resistance (LPR) technique, the best anti-corrosion properties were demonstrated by the samples that were passivated in a Cr(III) solution with the addition of Zr compound and HF and in a Cr(III) solution with the addition of Co compound and HF.

PL

Próbki aluminium serii 5005A poddano procesowi pasywacji z wytworzeniem powłoki konwersyjnej na bazie związków Cr(III). Wykazano, że odporność korozyjna aluminium poddanego obróbce galwanicznej w kąpieli zawierającej jednocześnie związki cyrkonu i kobaltu, mierzona w 0,05 M roztworze NaCl, nieznacznie wzrosła w stosunku do odporności korozyjnej aluminium w stanie dostarczenia, tzn. bez powłoki konwersyjnej. W przypadku obróbki galwanicznej aluminium w kąpielach, które zawierały osobno związki kobaltu lub cyrkonu, uzyskano wyraźny wzrost odporności korozyjnej w stosunku do aluminium w stanie dostarczenia. Analiza SEM wykazała, że w obecności jednocześnie dodatku cyrkonu i kobaltu powstała najbardziej rozwinięta powierzchnia. W przypadku zastosowania tylko dodatku cyrkonu jasne wytrącenia sferoidalne występują lokalnie. Analiza EDS wykazała obecność C, O, Mg, Al i Si, niewielkich ilości Cr, Zr, F na powierzchni aluminium pokrytego powłoką konwersyjną Cr + Zr + HF. Podczas pomiarów techniką liniowego oporu polaryzacji (LPR) najlepsze właściwości antykorozyjne wykazały próbki poddane pasywacji w roztworze Cr(III) z dodatkiem związków Zr i HF oraz w roztworze Cr(III) z dodatkiem związków Co i HF.

19

Fabrication, microstructure, and machinability of aluminum metal-matrix composites

Kathiravan S., Thanigaivelan R., Suresh P.

Materials Science Poland

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2022

|

Vol. 40, No. 3

112--124

EN

Today, researchers across the world focus on sustainable products, and, accordingly, it is now imperative to develop sustainable MMCs. In line with this, ongoing experimental work aims to fabricate aluminum 6061 MMC with ground granulated blast furnace slag (GGBS) and study the micro-structural and machinability characteristics. A liquid state stir casting setup is used to melt aluminum 6061 alloy and reinforced with 2.5 wt.%, 5.0 wt.%, and 7.5 wt.% of GGBS. X-ray diffraction (XRD) studies were used to identify the chemical elements that were present in the fabricated samples. In order to observe the formation of any secondary elements, energy-dispersive X-ray spectroscopy and scanning electron microscopy (SEM) were utilized on the cast composites. Through the milling process, the influence of the GGBS reinforcement composition on the surface roughness (SR) and material removal rate (MRR) of aluminum 6061 MMC was examined, considering the parameters of spindle speed, feed rate, depth of cut, and reinforcement composition percentage. The L9 orthogonal array (OA) was used to investigate the results of the experiments, and the Taguchi technique was used to optimize the process. The best MRR value was produced by the feed rate (B3) of 260 mm3/min and the depth of cut (C3) of 0.75 mm. The study ascertained that the lower SR value is attained corresponding to a spindle speed of 1,250 rpm, a feed rate of 220 mm3/min, a depth of cut of 0.25 mm, and a reinforcement composition percentage of Al 6061 with 5% GGBS.

20

Manufacturing and properties of al-al alloy bimetallic composites obtained from powders by hot extrusion

Wojtaszek Marek, Zyguła Krystian

Composites Theory and Practice

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2022

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R. 22, nr 4

211--218

EN

This paper presents the process of manufacturing bimetallic composites in the shell-core system. Al17Si5Fe3Cu1.1Mg0.6Zr alloy powder was used for the shell. Pure aluminum was used as the core of the composite, respectively, in the form of a cast and then rolled rod, and in the form of a semi finished product obtained from aluminum powder. The semi-finished powders were produced by means of the uniaxial hot pressing method. From the components prepared in this way, an extrusion chargé was made by machining in an alloy shell-core system. Permanent bonding of the components and forming the required shape of the composites was carried out using direct hot extrusion under isothermal conditions. It was confirmed that the application of powder metallurgy technology for the production of one or both component materials makes it possible to conduct the extrusion of the components with significantly different plasticity without violating the cohesion of the layers. This approach made it possible to produce layered composites with high-strength properties of the outer layer and with a ductile core. The microstructural state of the components was evaluated, focusing on the continuity of the transition zone between the components. Observations of the separation lines between the layers revealed that the zone between the components was continuous, which was found for both composites, regardless of the examined cross-section. On this basis, it was concluded that the direct hot extrusion process, carried out under the adopted parameters, made it possible to combine the components very well. Selected properties of the layered composites were also determined. It was shown that the proposed method, combining powder metallurgy and hot forming technologies, makes it possible to obtain a continuous connection of components and produce products with properties significantly differentiating in the core and shell zones. These properties can be controlled by appropriate selection of the components, as well as by the method of manufacturing the core. Potential applications of the studied materials include the manufacture of bimetallic components for operation in conditions where significantly different properties of the outer zone and the core are required.