Enhanced photoelectrochemical performance of Al-doped ZnO thin films prepared by co-spray technique

The non-aqueous sol–gel synthesis of aluminum zinc oxide (AZO) nanocrystals with controllable size and morphology at comparatively low temperatures is presented. By varying the reaction chemistry, customized aluminum zinc oxide nanorods and nanospheres with adjustable composition and tailored morphology between 0D and 1D were obtained. We furthermore show that the bandgap can be engineered by the Al content. Additionally, the growth kinetics and the influence of various process parameters such as the reaction temperature and precursor concentration as well as the scale-up from a 45 mL autoclave to a 500 mL reactor were investigated.

/pdf/aluminum-zinc-oxide-nanostructures-with-customized-size-and-1k5kj63q1j.pdf

Aluminum zinc oxide nanostructures with customized size and shape by non-aqueous synthesis

The mix of two different type of fibres, one is natural and another one is synthetic fibres were employed as reinforcing media in this study, and epoxy based polymer resin was employed as the matrix phase. S-glass and luffa fibres had been bonded with epoxy matrix to create a novel composite by compression moulding and to measure the effect of this hybridization in composite laminate utilising five different sequencing. To determine the mechanical characteristics of this composite material using tensile, flexural, and compression strength, a specimen named 'SL4' had shown the highest mechanical strength, resulting in a tensile properties of 253 MPa, compression strength of 234 MPa, and flexural characteristics of 237 MPa. The increment in mechanical characteristics is found to exhibiting around 20% increase comparing to the specimen having next higher value in all the properties. The results evidenced that the presence of luffa fibre layers at the interior most portion of the composite displayed the progressive values in all the investigated mechanical characteristics.

https://doi.org/10.1088/1742-6596/2272/1/012024

Investigating Mechanical Properties of Hybrid Polymer Composite Reinforced with S-Glass and Luffa Fibres

The hypoeutectic aluminum alloy (AlSi10Mg) is a well-known candidate material used predominantly for its processability and inherent characteristics in metal-based additive manufacturing. Besides, transition metal carbide, such as niobium carbide (NbC), is added to the AlSi10Mg, enhancing its mechanical properties and preferably its wear resistance to the matrix. However, in additive manufacturing, the mixed powder’s flowability is a prerequisite for determining the final properties of the specimens. In this study, mixed powder flowability analysis was carried out through the regular mixing of AlSi10Mg with a varying weight percentage of NbC conducted in the planetary ball mill with different time, speed, and NbC composition following the Central Composite Design (CCD), with a total of 20 experiments. Here, regular mixing was preferred to retain the morphology of the AlSi10Mg (spherical shape) instead of ball milling, which contributes to the degradation of the powder’s shape and size. Finally, based on the combined analysis of apparent density (AD), tapped density (TD), and static angle of repose (SAoR), the flowability characteristics of the mixed powders (AlSi10Mg  +  X % NbC) were evaluated. The optimum combination (AlSi10Mg + X% NbC) was attained based on the composite desirability criteria.

/pdf/influence-of-planetary-ball-mill-parameters-on-powder-f2y88xbs.pdf

Influence of Planetary Ball Mill Parameters on Powder Flowability of AlSi10Mg with Niobium Carbide Using Central Composite Design (CCD)

Dynamic analysis and structural simulation of aluminum composite material based automobile chassis

Powder-based additive manufacturing (PAM) is a potential fabrication approach in advancing state-of-the-art research to produce intricate components with high precision and accuracy in near-net form. In PAM, the raw materials are used in powder form, deposited on the surface layer by layer, and fused to produce the final product. PAM composite fabrication for biomedical implants, aircraft structure panels, and automotive brake rotary components is gaining popularity. In PAM composite fabrication, the aluminium cast alloy is widely preferred as a metal matrix for its unique properties, and different reinforcements are employed in the form of oxides, carbides, and nitrides. However, for enhancing the mechanical properties, the carbide form is predominantly considered. This comprehensive study focuses on contemporary research and reveals the effect of metal carbide's (MCs) addition to the aluminium matrix processed through various PAM processes, challenges involved, and potential scopes to advance the research.

Processing of Aluminium-Silicon Alloy with Metal Carbide as Reinforcement through Powder-Based Additive Manufacturing: A Critical Study

The undoped and Al-doped ZnO (AZO) nanostructures were synthesized by using simple hydrothermal process with two different pH values 6 and 10. The structural and optical properties of the ZnO and 0.5 % AZO nano particles were investigated using field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscope, atomic force microscope, X-ray diffraction (XRD), Ultraviolet–visible (UV) spectroscopy and photoluminescence (PL). It is observed from XRD results; on aluminium doping the crystalline size reduces significantly. It can be clearly seen from the FESEM images that Al doping causes the crystalline structure of ZnO to agglomerated small grain nano particles and TEM confirms that the particles are of nanometer size. The UV absorption indicates that blue shift of the samples increases the optical band gap, and decreases the average crystallite size. In the PL spectra, undoped ZnO exhibit an excitonic peak in the UV region and a defect-related peak in the visible region, whereas Al doping leads to a suppression of c lattice parameter and blue shift of luminescence with blue and green emission.

Experimental investigation on structural and optical properties of ZnO: AZO nano particles by hydrothermal synthesis

Microstructure and Mechanical Properties of AlSi10Mg/NbC Composite Produced by Laser-Based Powder Bed Fusion (L-PBF) Process

The present-day structural application requires advanced materials at extreme conditions, and the development of it is not economically feasible. As a result, existing material in the composite form has more visibility to suit the purpose. The material's strengths and qualities must be examined before it can be recommended for use in harsh conditions. In the present study, Al2O3 (3, 6, 9, 12, and 15 wt.%) and ZrO2 particles (2 wt.%) are reinforced with Al-Mg-Si alloy (Al 6061), which possess good isotropic behaviour and better interface bonding. The double stir casting process was adopted for the hybrid composite development, and the samples were cold rolled to reduce grain size and pores in the composites. The developed composites were subjected to mechanical characterisation tests such as hardness, tensile, compression, impact and flexural tests. An increase in reinforcement percentage enhances the mechanical properties. The improvement was attributed to the high thermal mismatch and reduction in the inter-particle distance by cold rolling and the reinforcements. Scanning electron microscope microstructural examination was conducted, and even dispersion of 3 to 15 wt.% Al2O3 reinforcements was observed. Tensile elongation decreases with an increase in reinforcement percentage. High elastic modulus and temperature mismatch between matrix and reinforcements increase the strength of the composites. The fracture behaviour of the composites generally showed dimples which are characteristics of ductile fracture, except at 15 wt.% Al2O3 / 2 wt.% ZrO2 showed a large portion of cleavage planes and grain cracking. The Al-Mg-Si alloy is reinforced with 9 wt%. Al2O3 / 2 wt.% ZrO2 had the best properties suitable for its use in different structural applications.

Experimental investigation on the mechanical performance of the Al2O3 and ZrO2 added Al-Mg-Si alloy for structural applications

In this study, undoped ZnO and aluminium doped ZnO (AZO) nanopowders have been successfully synthesized by low temperature hydrothermal method. In this simple method, Zinc nitrate and hexamethylenetetramine (HMT) were used as precursors for synthesising pure ZnO and aluminium nitrate is used as doping material for AZO with different molar ratios of 1%, 0. 5% and 0. 25%. The structural properties of undoped and Al doped ZnO powders has been analysed by X-ray diffraction (XRD), Scanning electron microscopy (SEM) and energy dispersive X ray analysis (EDS). XRD results indicated that all the samples were preferentially grown in c-axis. SEM images of ZnO showed that the well faceted hexagonal nano rods were grown. Also, the SEM images of AZO are evidence for the effect of molar ratio variation on its morphology. The compositional analysis carried out using EDS revealed that Zn, O and Al are present in the sample.

R. Raj Mohan

Papers

Processing of Aluminium-Silicon Alloy with Metal Carbide as Reinforcement through Powder-Based Additive Manufacturing: A Critical Study

Experimental investigation on structural and optical properties of ZnO: AZO nano particles by hydrothermal synthesis

Microstructure and Mechanical Properties of AlSi10Mg/NbC Composite Produced by Laser-Based Powder Bed Fusion (L-PBF) Process

Experimental investigation on the mechanical performance of the Al2O3 and ZrO2 added Al-Mg-Si alloy for structural applications

Synthesis of undoped and Al doped ZnO nanostructures: Molar ratio dependency and structural properties