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.

Hot press sintering effects and wear resistance of the Al-B4C composite coatings of an AA-2024 alloy

In this study, the surface of AA-2024 alloy substrate was coated with an Al-B4C reinforced composite using hot press sintering. Al and B4C powders were synthesized by mechanical alloying. To this end, four samples were prepared. As a reference sample, AA-2024 substrate was coated with pure Al powder under 110 MPa pressure. In the other samples, the AA-2024 substrate was coated with metal matrix composites (MMCs) contained in Al-5 wt.-% B4C at 90, 110 and 130 MPa. The microstructure of the transition zone formed between the AA-2024 substrate and the coating layer of the coated samples, the microstructure of the Al/B4C MMCs coating, the macro hardness, the linear reciprocating and forth wear resistance of the coating layer were investigated. In addition, an optical microscope (OM), scanning electro microscope (SEM) images and EDS analysis of the microstructure were used. It was observed that the B4C powders were homogeneously distributed in the Al matrix in the microstructure of the coating layer. It was also found that the gaps between the grains in the microstructure of the coating layer and their size decreased with an increase in pressing pressure. Accordingly, it was concluded that macro hardness increased and weight loss decreased.

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.

Evaluation of Corrosion Inhibition Efficiency of Aluminum Alloy 2024 by Diaminostilbene and Azobenzene Schiff Bases in 1 M Hydrochloric Acid

The Schiff base compounds N,N ′ -bis(salicylidine)-4,4 ′ –diaminostilbene(SDS) and N,N ′ -bis(salicylidine)-4,4 ′ -diamino azobenzene(SDA) were synthesized, and their molecular structure was determined by FT-IR and 1H NMR. The corrosion inhibitions of Schiff base compounds on aluminum alloy 2024 in 1 M hydrochloric acid were evaluated by potentiodynamic polarization, impedance techniques, weight loss method, and scanning electron microscopic technique. The potentiodynamic polarization (PDP) studies revealed that SDS and SDA compounds acted predominantly as cathodic inhibitors. The electrochemical impedance spectroscopic (EIS) parameters confirmed the adsorption of SDS and SDA molecules over the surface of aluminum alloy 2024 alloy by forming an inhibitive layer. The weight loss studies showed that the inhibition efficiency of these compounds increases directly with concentration and decreases with an increase in solution temperature and immersion time. The thermodynamic parameters were calculated to investigate the mechanism of corrosion inhibition. The SDA was found to be more effective than SDS and followed the Langmuir adsorption isotherm model. The scanning electron microscopy (SEM) results revealed that the deterioration of the alloy surface is minimal in the presence of an inhibitor. Both Schiff base molecules exhibited superior corrosion inhibition for aluminum alloy 2024 alloy in HCl medium.

Experimental Investigation on Surface Roughness and Metal Removal Rate of Aluminium 2024 Alloy

The purpose of this work is to investigate experimentally the surface roughness and MRR while machining of aluminium 2024 alloy which is prepared by powder metallurgical technique. Aluminium 2024 alloy prepared with different composition such as Pure Al, 1.5 W% of Mg and 2-6 % of Cu powders. Powders are blended with ball milling machine according to the composition required and specimens are prepared in square shape die (25*25mm) by applying uniaxial load of 200Mpa. The sintering process was performed at 594 0C for 60 min and cooled at room temperature. SEM and XRD analysis was carried out to know various characteristics like green density, dimensional changes during sintering, sintering density, mechanical properties and microstructures. Finally the Surface roughness and MRR during machining with CNC milling machine at different depth of cuts was also evaluated. Keywords: Aluminium 2024 alloy, surface roughness, MRR, SEM and XRD analysis

Comparative study: Impact of Ball burnishing and shot peening Process on Aluminium 2024 alloy

Compressive residual stress is the major aspect in the extension of the fatigue life of aeroengine components. In this study, a modified burnishing surface treatment and conventional shot peening process was used was proposed to improve surface integrity characteristics such as surface finish, hardness, and stable, advantageous compressive residual stress in turned Cylindrical Aluminum 2024Specimen. In burnishing process, a rolling rigid spherical HSS ball is pressed across an Aluminum 2024Specimen under definite fluid pressure generated by the hydraulic unit and also shot peening was carried out at a shot velocity of 300 m/s. This research examined the effect of burnishing treatment and shot peening process on beneficial compressive residual stresses.