Aerospace alloys with reduced wall thickness but possessing higher hardness, good tensile strength and reasonable corrosion resistance are essential in manufacturing of structures such as fuselage. In this work, friction stir welding has been carried out on such an aerospace aluminum alloy AA8090 T87 which contains 2.3% lithium. Tool rotational speed of 900 rpm and traverse speeds of 90 mm/min., 110 mm/min. are the welding parameters. Hardness analysis, surface roughness analysis and corrosion analysis are conducted to analyze the suitability of the joint for the intended application. The samples were corrosion tested in acid alkali solution and they resulted in the formation of pits of varying levels which indicate the extent of surface degradation. Hardness of the samples was measured after corrosion analysis to observe the changes. The analysis suggests that the change in tool traverse speed transformed the corrosion behavior of the joint and affected both the hardness and surface roughness which mitigated the quality of the joint.

Several components are made from Al-Mg-based composites. MoS₂ is used to increase the composite’s machinability. Different weight percent (3, 4, and 5) of MoS₂ are added as reinforcement to explore the machinability properties of Al-Mg-reinforced composites. The wire cut electrical discharge machining (WEDM) process is used to study the machinability characteristics of the fabricated Al-Mg-MoS₂ composite. The machined surface’s roughness and overcut under different process conditions are discussed. The evaluation-based distance from average solution (EDAS) method is used to identify the optimal setting to get the desired surface roughness and overcut. The following WEDM process parameters are taken to determine the impact of peak current, pulse on time, and gap voltage on surface roughness, and overcut. The WEDM tests were carried out on three different reinforced samples to determine the impact of reinforcement on surface roughness and overcut. The surface roughness and overcut increase as the reinforcement level increases, but the optimal parameters for all three composites are the same. According to EDAS analysis, I₃, Ton₂, and V₁ are the best conditions. Furthermore, peak current and pulse on-time significantly influence surface roughness and overcut.

The aerospace industries are focused on lightweighting with alloys having good tensile strength, fracture toughness, fatigue resistance, and corrosion resistance. The friction stir welding technology is one of the productive techniques in the aerospace industry to join such alloys with little ease. This paper deals with the composition of alloying elements that makes the structure lightweight and the impact of the precipitates evolved out of the selected alloying elements on the mechanical properties such as tensile strength and hardness of the joint in the aerospace alloys such as AA2xxx conventional aluminium alloys, AA2xxx lithium-based aluminium alloys, and AA7xxx aluminium alloys.

This research work is aimed to convert fish scale wastes as an effective reinforcement in polylactic acid (PLA) as a new bio-composite filament for fused deposition-based 3D printing applications. Various concentrations of fish scale particles (0, 10, 20, and 30%) were used to make the filaments. The performance of the developed filaments was assessed by printing the filament into various test specimens to perform tensile, flexural, impact, hardness, and water absorption experiments as per the ASTM standards. The outcomes of the results show that the PLA/fish scale powder (20%) composite has performed well than the remaining composites. Furthermore, the adding 20% fish scale powder increased the tensile strength and flexural strength of the 3D printed PLA composite by 15% and 39.78% respectively. This is evident that the novel bio-composite exhibited better properties than the pure polymer making it a potential replacement as bone-grafting material and scaffolds for bio-engineering applications.

In this study, powder metallurgy process has been utilized to produce the composite materials. Pure aluminium (Al) has been selected as the matrix material for the preparation of composite materials. 4% of magnesium (Mg) has been added as the alloying element, whilst molybdenum disulphide (MoS₂) is reinforced with a varying wt.% (2, 4 & 6). The intent of this work is, to evaluate some basic mechanical properties (density, microhardness, compression strength and toughness), surface degradation properties (corrosion and wear), and electrical conductivity of the fabricated composite materials. Moreover, SEM mapping and EDAX analysis have been conducted to confirm the presence of reinforcement particles with homogenous distribution in the matrix material and to do the fractographic study of the compressive strength tested samples. The density of the composite material Al-4% Mg-6%MoS₂ has been increased compared to the density of pure Al material. Micro Vickers hardness test shows that Al-4% Mg-6%MoS₂ composite has 32.86% more hardness as compared to that of pure Al material. Compressive strength of the composite material with the higher wt.% of MoS₂ is found to be 181.81 N/mm², while Al material has only 167.52 N/mm². The buckling formation during the compression test is avoided in the composite material owing to the existence of MoS₂ particulates. The wear loss of composite materials is found low as compared with the unreinforced Al material, owing to the solid lubricant property of MoS₂ particles, and hence, coefficient of friction (COF) is also lessened with the increase in the MoS₂ wt.%. Also, the MoS₂ reinforced materials show good resistance to corrosion due to the presence of molybdenum, which acts as a consistent layer obstacle to prevent the surface from further degradation.