Process Evaluation and Numerical Optimization in Friction Stir Welding of Dissimilar AMCs

In recent times, any engineering material is deemed worthwhile only if it satisfies functional characteristics such as weldability, formability, machinability, etc. Aluminum-based metal matrix composites have extensive usage in modern automobile parts, aircraft components, and ship structures, mainly due to their attractive properties such as low cost, high strength-to-weight ratio, excellent corrosion and wear resistance. Friction stir welding is one of the most versatile solid-state joining processes to ensure weldability between two AMC plates. In this research work, an analysis of FSW process through parameters (e.g., composition of alumina, spindle speed, feed, etc.) in joining Alumina reinforced aluminum alloy composites Al 6061 and Al 2024 together at various proportions by analyzing properties like impact strength, hardness, flatness, and ultimate tensile strength has been done. Finally, optimization is carried out to select the best possible combination using a multi-attribute decision-making technique called the complex proportional assessment of alternatives.

Nano-Surface Composite Coating Reinforced by Ta2C, Al2O3 and MWCNTs Nanoparticles for Aluminum Base via FSP

In the present work, an advanced technique was applied to coat an Al 2024 alloy with a surface composite layer reinforced with various nanoparticles. The surface of Al 2024 aluminum alloy was modified with Ta2C, Al2O3 and multi wall carbon nanotubes MWCNTs nanoparticles by friction stir process (FSP). An improvement in the surface of the fabricated nanocomposite due to the refinement of the microstructure grains was achieved. In addition, a significant improvement in the hardness and wear behavior was observed. The reinforcement particles were incorporated into double and triple hybrid composite particles to determine the most effective combination for the controlled properties. The results showed that for the composite reinforced with a double hybrid of Al2O3 and MWCNTs, the microstructure grains of the fabricated nanocomposite surface were refined by 40 times. The hardness was significantly improved, i.e., it was increased by 48% by incorporating the triple reinforcement (Ta2C, Al2O3, and MWCNTs) into the surface of Al 2024 aluminum alloy. The results of wear properties were in agreement with the results of hardness; the maximum wear resistance was obtained for Al 2024-Ta2C + Al2O3 + MWCNTs, and the wear rate was reduced by 11 times.

Tensile and wear properties of repetitive corrugation and straightened Al 2024 alloy: an experimental and RSM approach

Repetitive Corrugation and Straightening (RCS) on sheet geometries causes Cyclic Plastic Deformation, resulting in potential improvements of mechanical characteristics in metals and alloys. In this study, sample sheets of Al 2024 are subjected to severe plastic deformation with specially designed corrugated rollers to generate heterogeneous repeated plastic deformation at room temperature. The material shows enhanced properties under severe plastic deformation, with 5.07% increase in tensile strength, compared to unprocessed material. Maximum tensile strength was observed at annealed temperature of 150 °C is of about 3.49% increase in tensile strength over other temperature conditions. A wear study was carried out by considering the processed sheet that yields high tensile strength (annealed at 150 °C) by varying process parameters like sliding distance, load and sliding velocity as per design of experiments. In comparison to all other combinations, the wear resistance was shown to be better with a sliding distance of 6000 m, a load of 9.81 N, and a sliding velocity of 1.45 m s−1. The Response Surface Methodology (RSM) approach was adopted for comparing purpose, the experimental findings are found to be more similar to the RSM approach’s outcomes.

Effect of Carbonitriding on Tribomechanical and Corrosion-Resistant Properties of Friction Stir Welded Aluminium 2024 Alloy

Friction stir welding (FSW) is extensively used to join aluminium alloys components in space and aircraft industries. Al 2024 is a heat-treatable aluminium alloy with copper as the primary alloying element which has good strength and fatigue resistance. This paper investigates the effect of carbonitriding surface modification on the hardness, tensile strength and impact strength of FSW welded Al 2024 joints. The friction stir welding was performed on three different sets of aluminium alloy (Al2024:Al2024, Al2024: carbonitrided-Al2024, carbonitrided-Al2024: carbonitrided-Al2024) at two different tool rotation speed (TRS) and two welding speed using cylindrical pin tool. The carbonitriding pre-treatment of Al-2024 alloy demonstrated significant improvement in the tensile strength, percentage elongation, abrasion wear resistance and corrosion resistance with the sacrifice of impact strength. The maximum tensile strength of all three sets of samples after FSW was recorded in descending order of (i) carbonitrided-Al2024:carbonitrided-Al2024 (ii) Al2024:Carbonitrided-Al2024 and (iii) Al2024:Al2024. The friction stir welded joint of carbonitrided aluminium alloy exhibited best abrasive wear resistant and corrosion resistant properties.

Analytical and FEM Analyses of High-Speed Impact Behaviour of Al 2024 Alloy

The present work investigates the impact behaviour of Al 2024-T3 alloy using FEM analysis performed through LS DYNA software. Johnson–Cookvisco-plastic model is used to study the ballistic impact resistance of target Al alloy impacted by a rigid steel cylindrical projectile. The tensile properties of Al 2024-T3 alloy reported in the literature are used to estimate the J.C. model parameters. Impact velocities within a range of 50 m/s–900 m/s of the projectile were triggered onto Al alloy target thicknesses in the range of 3.18 mm–6.35 mm. To understand the accuracy of the FEM model, an analytical model proposed by Chen et al. for blunt-nosed projectiles on the ductile targets was used to compare with the obtained residual velocities from FEM simulations. It was observed that the ballistic limit velocities have led to the highest energy absorption behaviour of the Al 2024-T3 alloy for an impact velocity of 183 m/s and a 6.35 mm target thickness. The ballistic limit velocities have increased from 97 m/s to 183 m/s for the considered thickness range of 3.18 mm–6.35 mm. The impact failure was observed to have a petalling formation with two petals for thinner targets, while a full-fledged plugging with no petal formation for the 4.00 mm and 6.35 mm target thicknesses was observed.

Optimization of Interfacial Energy for Langer-Schwartz Based Precipitation Simulations

Precipitation kinetics were investigated in select Fe, Ni, and Al alloys using a CALPHAD based precipitation model based on Langer-Schwartz theory. Thermodynamic and kinetic data are taken from commercially available CALPHAD software, but reliable interfacial energy data for precipitates needed for the calculations is often lacking. While models exist to approximate these interfacial energies, this study has focused on deriving more reliable estimates by comparison with experimental data. By performing simulations with thermal histories, nucleation sites, and precipitate morphologies that closely replicate experimental data found in literature, the interfacial energies were optimized until volume fraction and mean radius values closely matched the published data. Using this technique, interfacial energy values have been determined for carbides in Grade 22 low alloy steels, delta phase in Ni 625 and 718, SPhase in Al 2024, and Q’ and β’’ in Al 6111, and can be used for future predictive precipitation simulations.

The Influence of Temperature in the Al 2024-T3 Aluminum Plates Subjected to Impact: Experimental and Numerical Approaches

In this paper, perforation experiments were carried out and numerically modelled in order to analyze the response of 2024-T3 aluminum alloy plates under different initial temperatures T0. This alloy has a particular relevance since it is widely used as a structural component in aircrafts, but it is also interesting for other sectors of industry. A gas gun projectile launcher was used to perform impacts within initial velocities V0 from 40 m/s to 120 m/s and at temperatures varying from 293 K to 573 K. A temperature softening of the material was observed which was manifested in the reduction in the ballistic limit by 10% within the temperature range studied. Changes in the material failure mode were also observed at different test conditions. Additionally, a finite element model was developed to predict the material response at high velocities and to confirm the temperature softening that was observed experimentally. An optimization of the failure criterion resulted in a reliable model for such mild aluminum alloys. The results reported here may be used for different applications in the automotive and military sectors.

Analisa Kekuatan Sambungan Rivet Zig-Zag dan Inline dengan Plat Al 2024-T3

Kualitas sambungan rivet berperan penting untuk menahan beban khususnya pada struktur badan pesawat. Umumnya terdapat dua pengaturan susunan rivet yakni zig-zag dan inline. Penelitian ini bertujuan untuk menganalisa kekuatan kedua jenis sambungan rivet tersebut. Pengujian spesimen dilakukan dengan 2 cara, yakni pengujian secara riil yang mengacu pada standard EN ISO 12996:2013 tentang pengujian destruktif pada sambungan dan pengujian secara numerik menggunakan perangkat lunak Ansys 2020 R2. Dua spesimen uji tersebut masing-masing memiliki susunan rivet zig-zag dan inline dengan diameter rivet Ø 3,2 mm dan pelat Al 2024-T3 tebal 0,8 mm dan lebar 37 mm. Hasil pengujian Tarik menunjukkan bahwa susunan rivet zig-zag dapat menerima beban maksimum sebesar 6,01 kN sedangkan susunan rivet inline 5,73 kN. Sedangkan pengujian numerik menunjukkan bahwa tegangan maksimum ekuivalen von-Mises pada susunan rivet zig-zag sebesar 930,8 MPa sedangkan susunan rivet inline sebesar 865,1 MPa.