K. M. Sathish Kumar

This comprehensive review focuses on the most recent advances in electron backscatter diffraction (EBSD) methods in the context of materials science and includes a thorough evaluation of the sample preparation procedures unique to EBSD as well as a complete examination of the important operational parameters inherent in EBSD setups. This review highlights the importance of customizing EBSD parameters for precise microstructural imaging and enhancing understanding of material behavior. While some studies have explored grain boundary characterization, stored energy, and crystallographic orientation using EBSD, there is a clear need for more comprehensive investigations to fully leverage its capabilities. Additionally, there is a significant gap in understanding the optimal choice of the reference plane in EBSD analysis, indicating the necessity for further research to improve EBSD analyses’ accuracy and efficacy. The review seeks to present a detailed and contemporary viewpoint on the many applications, sample preparation techniques, and optimal operational considerations that jointly increase the adaptability and efficacy of EBSD in materials science research by relying on the relevant literature.

The present work focuses on the effect of multistage solution heat treatment (MSHT) and artificial aging on two-stage stir-cast LM4 + TiB₂ (1, 2, and 3 wt.%) composites on the mechanical properties as compared to as-cast and single-stage solution heat-treated (SSHT) composites. Two novel tests, viz. the confirmation hardness test and the chemical analysis test, were performed to ensure the soundness of the casting and uniform distribution of TiB₂ within the matrix. Samples subjected to MSHT + aging at 100–200 °C displayed the highest hardness and UTS values compared to as-cast and SSHT + aging at 100–200 °C samples. Compared to as-cast alloy, peak-aged samples of 1–3 wt.% (MSHT + aging at 100 °C), hardness values improved from 107–150%, and UTS values improved from 47–68%. The presence of metastable phases (θ′-Al₂Cu and θ″-Al₃Cu) and of hard TiB₂ particles are the reason for the improvement in the properties. Peak aged LM4 + 3 wt.% TiB₂ composite displayed the highest hardness of 175 VHN and UTS of 251 MPa. Fracture analysis of the LM4 alloy showed dimple rupture, and its composites revealed quasi-cleavage fracture. Based on the overall results, the inclusion of TiB₂, MSHT, and artificial aging treatment on the LM4 alloy significantly influenced the composites’ mechanical properties.

Neodymium – Iron – Boron (NdFeB) permanent magnets of 12.5 mm thickness and 50 mm diameter are chosen for analyses because of their higher remanence and coercivity. Experimental analyses were carried out with Copper discs of thickness 4 mm, 6 mm and 8 mm at 2000 rpm, 3000 rpm, 4000 rpm and 5000 rpm. Experiments were conducted with three different positions of magnets such as 2 coaxial magnets, single magnet and single magnet with sudden application conditions. The brake parameters recorded are % speed reduction, deceleration and time taken. In 2 coaxial magnets condition, brake parameters are better in 6 mm thick disc. In single magnet condition, the brake parameters in 6 mm thick disc are found to be more consistent than 4 mm and 8 mm thick discs. In single magnet with sudden application condition, in 4 mm thick disc, the brake parameters are found better. During analysis, very high repulsion was experienced by magnet with 8 mm thick Copper disc at all the above mentioned speeds in single magnet with sudden application condition. For high speed train applications, single magnet condition with 6mm thick disc may be suitable. For high speed automotive applications, single magnet with sudden application condition with 4 mm thick disc may be suitable.