Showing papers on "Aluminium alloy published in 2020"

Wear behaviour analysis on aluminium alloy 7050 with reinforced SiC through taguchi approach

Abstract: Aluminium alloy is the popular material in the world to produce lot of light weight parts with high strength, in additionally reinforcement is consider to these alloy is improve its strength. In this investigation consider the AA7050 aluminium alloy as a base material with reinforcement of Silicon Carbide (SiC) at various percentage level like as 0%, 4 % and 6 %. The wear of this composites are analysed through the design of experiments (Taguchi approach) for optimize the process parameters. This wear study is considered the parameters are Sliding velocity in m/s (1, 2 and 3), Sliding distance in m (1000, 1400 and 1800) and percentage of composition (0%, 43% and 6%). For this experimental investigation the sliding distance as most significant factor among three. The microstructure analysis demonstrated that there is a SiC particles which reduces wear of the samples.

Effect of reinforced aluminium alloy LM30 with pure ceramic particles to evaluate hardness and wear properties

Abstract: In this paper, the hardness and wear properties of pure ceramic particles like silicon carbide, boron carbide and graphite are considered in micron size with the reinforced aluminium LM30 m...

Laser powder bed fusion of AA7075 alloy: Influence of process parameters on porosity and hot cracking

Abstract: Laser powder bed fusion (LPBF) is an attractive technology of manufacturing high-strength aluminium alloy parts for the aircraft and automobile industries, limited by poor processability of these alloys. This work was aimed at finding the process window for the LPBF manufacturing of defect-free components of AA7075 alloy. Optimization of the parameters was performed at each stage of the multi-stage research, i.e. for single tracks, thin walls and volumetric specimens. At each stage, the relation between LPBF parameters and defect formation with a focus on hot cracking was investigated and discussed. Due to the optimization of process parameters, the density of volumetric specimens above 99 % was reached and vaporization losses of the alloying elements were significantly reduced, but solidification cracks could not be eliminated. It was found that solidification cracks were formed by the liquid film rupture mode, mainly along columnar grain boundaries. The EDS microanalysis showed intergranular microsegregation, not only of the main alloying elements (Zn, Mg, Cu) but also of minor elements such as Si. Silicon may play a significant role in increasing susceptibility to cracking by increasing the stability of the liquid film. Reduction in the silicon impurity content in the AA7075 powder gives a chance to reduce susceptibility to cracking with no change of the alloy specification.

Mechanical Properties of SLM-Printed Aluminium Alloys: A Review.

Abstract: Selective laser melting (SLM) is a powder bed fusion type metal additive manufacturing process which is being applied to manufacture highly customised and value-added parts in biomedical, defence, aerospace, and automotive industries. Aluminium alloy is one of the widely used metals in manufacturing parts in SLM in these sectors due to its light weight, high strength, and corrosion resistance properties. Parts used in such applications can be subjected to severe dynamic loadings and high temperature conditions in service. It is important to understand the mechanical response of such products produced by SLM under different loading and operating conditions. This paper presents a comprehensive review of the latest research carried out in understanding the mechanical properties of aluminium alloys processed by SLM under static, dynamic, different build orientations, and heat treatment conditions with the aim of identifying research gaps and future research directions.

Direct joining of thermoplastic ABS to aluminium alloy 6061-T6 using friction lap welding

Abstract: A thermoplastic ABS and an aluminium alloy 6061-T6 were joined using friction lap welding (FLW). The joint characteristics were evaluated to investigate the effects of 6061-T6 surface and the weldi...

Comparative study on the microstructures and properties of wire+arc additively manufactured 5356 aluminium alloy with argon and nitrogen as the shielding gas

Abstract: This research explored the influences of shielding gases on the appearance of weld beads and the microstructures and mechanical properties of thin-wall samples using conventional gas metal arc welding as the heat source by using 5356 aluminium alloy welding wire as the raw materials and nitrogen (N2) and argon (Ar) as the shielding gases. The results showed that under the same parameters and after mono-layer single-bead welding was performed using N2 as the shielding gas, the bead height was higher, the bead width was narrower, and the penetration depth was shallower. The grain size of the thin-wall sample protected by N2 was 43.5–47.8 % smaller than that obtained under Ar protection. However, the sample protected by N2 contained many flaky nitrides, whose presence improved the microhardness but reduced the ultimate tensile strength (UTS) and plasticity. The average UTS of the thin-wall sample protected by N2 in the horizontal direction was 82.5 % of the UTS of the samples shielded using Ar. However, the average elongation in the horizontal direction of the samples protected by N2 was 18.6 % of that of the samples shielded by Ar. The mechanical properties of the sample protected by argon were more excellent.

Comparative Study on the Cavitation Erosion and Sliding Wear of Cold-Sprayed Al/Al2O3 and Cu/Al2O3 Coatings, and Stainless Steel, Aluminium Alloy, Copper and Brass

Abstract: The paper investigates the cavitation erosion (CE) and sliding wear (SW) resistance of cold-sprayed Al/Al2O3 and Cu/Al2O3 composites and studies them in relation to a set of metallic materials such as aluminium alloy (AlCu4Mg1), pure copper (Cu110), brass (CuZn40Pb2) and stainless steel (AISI 304). The coatings were deposited on stainless steel by low-pressure cold spray (LPCS) using Al (40 wt.%) and Cu (50 wt.%) blended with Al2O3 (60 and 50 wt.%, respectively) feedstocks. CE resistance was estimated by the stationary sample method according to the ASTM G32 standard. The SW test was conducted using a ball-on-disc tester with compliance to the ASTM G99 standard. Results obtained for the LPCS coatings show that the Cu/Al2O3 coating exhibits a denser structure but lower adhesion and microhardness than Al/Al2O3. The Al/Al2O3 and Cu/Al2O3 resistance to cavitation is lower than for bulk alloys; however, composites present higher sliding wear resistance to that of AlCu4Mg1, CuZn40Pb2 and stainless steel. The CE wear mechanisms of LPCS composites start at the structural discontinuities and non-uniformities. The cavitation erosion degradation mechanism of Al/Al2O3 relies on chunk material detachment while that of Cu/Al2O3 initiates by alumina removal and continues as layer-like Cu-metallic material removal. CE damage of metal alloys relies on the fatigue-induced removal of deformed material. The SW mechanism of bulk alloys has a dominant adhesive mode. The addition of Al2O3 successfully reduces the material loss of LPCS composites but increases the friction coefficient. Coatings’ wear mechanism has an adhesive-abrasive mode. In both CE and SW environment, the behaviour of the cold-sprayed Cu/Al2O3 composite is much more promising than that of the Al/Al2O3.

Effect of pulsed metal inert gas (pulsed-MIG) and cold metal transfer (CMT) techniques on hydrogen dissolution in wire arc additive manufacturing (WAAM) of aluminium

Abstract: Aluminium is one of the most experimented metals in the WAAM field owing to a wide range of applications in the automotive sector. Due to concerns over reduction of strength, elimination of porosity from wire arc additive manufactured aluminium is one of the major challenges. In line with this, the current investigation presents findings on hydrogen dissolution in solid aluminium and hydrogen consumed to form porosity along with its distribution as a function of heat inputs and interlayer temperatures in a WAAM 5183 aluminium alloy. Two varieties of WAAM, pulsed metal inert gas (MIG) and cold metal transfer (CMT), were explored. Samples made with pulsed metal inert gas (pulsed-MIG) process picked up more hydrogen compared to samples produced by cold metal transfer technique. Correspondingly, pulsed-MIG samples showed increased number of pores and volume fraction of porosity than samples manufactured using the cold metal transfer (CMT) technique for different heat input and interlayer temperature conditions. However, CMT samples exhibited higher amount of dissolved hydrogen in solid solution compared to pulsed-MIG process. In addition, heat input, interlayer temperature, and interlayer dwell time also played a key role in pore formation and distribution in WAAM-produced aluminium 5183 alloy.

Gradient microstructure and vibration fatigue properties of 2024-T351 aluminium alloy treated by laser shock peening

Abstract: To investigate the improvement in vibration fatigue and the strengthening mechanism of laser shock peening, a nanosecond laser was used to strengthen the 2024-T351 aluminium alloy. Accordingly, the microstructure, residual stress, nanohardness and surface roughness of the treated alloy were measured. Subsequently, the vibration fatigue damage and fatigue life were evaluated, and the vibration fracture morphology was observed. The results showed that the grains in the peened surface were refined. A residual stress of −141 MPa and a nanohardness of 3.1 GPa were obtained by laser shock peening. Based on the relationship between the peened microstructure and fracture morphology, it was deduced that an increase in the grain boundaries led to a lower crack initiation rate and a higher crack initiation life. The compressive residual stress decreased the crack growth rate and increased the crack growth life. Therefore, laser shock peening increases the total vibration fatigue life by about 63.5%.

Cold spray deposition of solution heat treated, artificially aged and naturally aged Al 7075 powder

Abstract: The deformation behaviour of particles and substrate in cold spray is dictated by the intrinsic properties of both materials, and their bonding directly affects the resulting properties of the deposited coating. The processing through heat treatment of aluminium alloy powders has only recently been developed for both cold spray and additive manufacturing, hence the necessity to evaluate and further understand the evolution of their properties. In this study, an Al 7075 gas-atomised powder was solution heat treated, quenched and subsequently aged. The powder in its as-quenched, T4 (natural ageing at room temperature for 21 days) and T6 (artificial ageing at 120 C for 24 h) condition was characterised through differential scanning calorimetry and scanning electron microscopy to evaluate the precipitation kinetics. Powders were cold sprayed using heated N2 at 500 C and 6.0 MPa and the resulting deposits were evaluated using tubular coating tensile and pull-off bond strength tests. The precipitation development in the gas atomised powder was found to be similar to the bulk alloys, with development of η′ precipitates during artificial ageing and Guinier-Preston zone formation and development during natural ageing. A relationship between the deposition efficiency of the powders and the coating properties was discovered and explained through an adapted densification mechanism based on powder tamping.

Biferrocenyl Schiff bases as efficient corrosion inhibitors for an aluminium alloy in HCl solution: a combined experimental and theoretical study

Abstract: The corrosion inhibitive capabilities of some ferrocene-based Schiff bases on aluminium alloy AA2219-T6 in acidic medium were investigated using Tafel polarization, electrochemical impedance spectroscopy (EIS), weight loss measurement, FT-IR spectroscopy and scanning electron microscopic (SEM) techniques. The influence of molecular configuration on the corrosion inhibition behavior has been explored by quantum chemical calculation. Ferrocenyl Schiff bases 4,4′-((((ethane-1,2-diylbis(oxy))bis(4,1-phenylene))bis(methaneylylidene))bis(azaneylylidene))bisferrocene (Fcua), 4,4′-((((ethane-1,2-diylbis(oxy))bis(2-methoxy-1,4-phenylene))bis(methaneylylidene))bis(azaneylylidene))bisferrocene (Fcub) and 4,4′-((((ethane-1,2-diylbis(oxy))bis(2-ethoxy-1,4-phenylene))bis(methaneylylidene))bis(azaneylylidene))bisferrocene (Fcuc) have been synthesized and characterized by FT-IR, 1H and 13C NMR spectroscopic studies. These compounds showed a substantial corrosion inhibition against aluminium alloy in 0.1 M of HCl at 298 K. Fcub and Fcuc showed better anticorrosion efficiency as compared with Fcua due to the electron donating methoxy and ethoxy group substitutions, respectively. Polarization curves also indicated that the studied biferrocenyl Schiff bases were mixed type anticorrosive materials. The inhibition of the aluminium alloy surface by biferrocenyl Schiff bases was evidenced through scanning electron microscopy (SEM) studies. Semi-empirical quantum mechanical studies revealed a correlation between corrosion inhibition efficiency and structural functionalities.

Effects of friction stir processing parameters on the wear resistance and mechanical properties of fabricated metal matrix nanocomposites (MMNCs) surface

Abstract: In this work, AA 2024 wrought aluminium alloy was reinforced with Al2O3 nanoparticles to fabricate surface metal matrix nanocomposites (MMNCs) via friction stir processing (FSP). Processing parameters, namely, rotational speed, traverse speed and the number of processing passes, were investigated to study their effects on the wear resistance, mechanical properties and hardness behaviour of the MMNCs. The mechanical properties of the materials were evaluated in a tensile test, and their hardness and wear properties were determined through Vickers microhardness and weight loss tests, respectively. Microstructural observation revealed that the processing parameters influenced the mechanical properties, wear behaviour, and hardness properties of the MMNCs. Specifically, the FSP refined the microstructural grains to a level 19 times better than that achieved with base alloy, thereby fine-tuning the average base alloy grain size of 135 μm to an average of 7 μm. Increasing the number of passes improved wear resistance by an average of 39%–70%, and implementing a third round of FSP enhanced the ultimate tensile strength and Young’s modulus by 40% and 20% on average, respectively. Finally, the incorporation of Al2O3 nanoparticles increased the hardness of the MMNCs by an average of 42%.

Friction stir lap welding of AA6061 aluminium alloy with a graphene interlayer

Abstract: The present study aims to enhance the strength of friction stir lap welded aluminum alloys by using an interlayer of graphene nanoplatelets (GNPs) at the weld interface. With GNP interlayer...

Mechanical Clinching and Self-Pierce Riveting of Thin Three Sheets of 5000 Series Aluminium Alloy and 980 MPa Grade Cold Rolled Ultra-High Strength Steel.

Abstract: One thin 5000 series aluminium alloy sheet and two thin 980 MPa grade cold rolled ultra-high strength steel sheets were joined by self-pierce riveting and mechanical clinching processes. The joinabilities for a combination of the aluminium and steel sheets in both processes were investigated for different die shapes in the experiment and finite element simulation. In self-pierce riveting, the three sheets were successfully joined for both combinations of the upper and lower aluminium alloy sheets by optimizing the shapes of a die and rivet. In mechanical clinching, the three sheets were successfully joined by an optimum die for the configuration of the upper aluminium alloy sheet. On the other hand, the three sheets for the configuration of the lower aluminium alloy sheet were not joined even by optimizing the die shape in the both finite element simulation and experiment, because the material flow of the steel sheets was insufficient to form the two interlocks. The tension-shear loads for the clinched and riveted sheets with the adhesive were almost the same, because the load for the adhesive was the highest. In the cross-tension test, however, the load by the adhesive was comparatively small.

The tribological behavior of hybrid aluminum alloy nanocomposites at High temperature: Role of nanoparticles

Abstract: The influence of the addition of hexagonal boron nitride nanoparticles and silicon carbide nanoparticles on dry sliding tribological properties of the AA2024-SiC-h-BN hybrid nanocomposites was evaluated at high-temperature environment using pin- on- disc wear testing machine at 30, 100, 200 and 300 °C under an applied load of 10, 20, and 30 N. The aluminium alloy 2024 matrix shows mild to rigorous wear at and above 100 °C under an applied load of 10, 20, and 30 N. AA2024–1.5 wt. % of SiC–2 wt. % of h-BN (H3), and AA2024–2 wt. % of SiC–1.5 wt. % of h-BN (H4) hybrid nanocomposites exhibit severe wear only at a 30 °C chamber temperature environment under an applied load of 30 N. The absence of severe wear phenomena in AA2024-SiC-h-BN hybrid nanocomposites is attributed to the formation of thin lubricant film, oxidation layer, and mechanical mixed layer on the pin surface. Abrasive, adhesive, and fracture wear are the main mode of wear mechanism for AA2024-SiC-h-BN hybrid nanocomposites in a high-temperature environmental chamber at 30, 100, 200 and 300 °C under an applied load of 10, 20, and 30 N.