https://dspace.iiti.ac.in:8080/jspui/handle/123456789/3646 Wed, 29 Jul 2026 03:49:08 GMT 2026-07-29T03:49:08Z https://dspace.iiti.ac.in:8080/jspui/handle/123456789/18844 Title: Directed Energy Surface Modifications: Ion Beam, Electron Beam, and Laser Beam (Texturing, Shock Peening, and Nitriding) Authors: Gangwar, Kaushal; Palani, Anand Iyamperumal Abstract: Surface modification involves enhancing the functional properties of a material's surface through alterations in its topography or chemical composition. Common techniques employed in surface modification include surface texturing, engraving, shock peening, and nitriding. These methods are widely utilized to improve surface characteristics such as wear resistance, friction, and chemical reactivity, tailored to specific industrial applications including electronics, automobile, defense, marine, and aerospace industries. Surface texture refers to the micro-to nano-scale features arranged in a specific pattern and distribution on a surface. These textures are designed to enhance and increase functionality to the surface by modifying its physical and chemical interactions with its environment. Engraving is a technique analogous to surface texturing, wherein patterns, designs, or text are inscribed onto the material's surface. Shock peening is a strengthening process that induces compressive residual stress into the target surface using a flexible high-energy tool. Shock peening helps to improve the fatigue properties by delaying crack initiation and increases wear resistance of the metallic surface by modifying it. However, nitriding is a process of diffusing nitrogen into the surface of the metal to improve hardness, wear resistance, and corrosion resistance. This chapter provides an in-depth explanation of highly flexible directed energy surface modification processes, including ion-beam, electron-beam (e-beam), and laser-beam based surface modification. These methods are distinguished by their precision and adaptability to various surface engineering applications. The chapter also delves into the mechanisms of material removal/chemical change inherent to each process, offering insight into the interaction between the energy source and the material surface. Additionally, it discusses the selection of the appropriate surface modification process based on the material and its application. © 2027 selection and editorial matter, Jinoop Arackal Narayanan and Kanmani Subbu Subbian; individual chapters, the contributors. Thu, 01 Jan 2026 00:00:00 GMT https://dspace.iiti.ac.in:8080/jspui/handle/123456789/18844 2026-01-01T00:00:00Z https://dspace.iiti.ac.in:8080/jspui/handle/123456789/18846 Title: Nickel-Titanium Endodontic File Degradation Assessment via Multi-sensor Fusion and Composite Wear Index: In-Vitro Study Authors: Tripathi, Apoorv; Kankar, Pavan Kumar; Miglani, Ankur; Jha, Hem Chandra Abstract: Standard root canal treatment involves cleaning, shaping, and enlarging the canals, a process that carries a high risk of file fatigue and failure. While Ni–Ti shape memory alloy files have reduced the frequency of these errors, their wear and fatigue remain abrupt and unpredictable for the practitioner. In this study, a measurement-driven methodology is developed to quantify the in-situ wear progression of a WaveOne Gold (#25) endodontic file using multi-sensor metrology and signal processing. Root canal procedures on extracted human teeth are instrumented with three synchronized sensors—a dynamometer (force), an accelerometer (vibration), and a microphone (acoustic emission)—to acquire high-resolution time-series data under realistic operating conditions. Parameters such as RMS, mean, and Standard deviation fail to provide an accurate understanding of file wear and are less sensitive to sudden changes due to file wear. In this study, force, vibration and acoustics signals are analyzed to calculate various time and frequency-based parameters. These parameters are then used to calculate the composite wear index of the file, indicating the relative wear of the file as opposed to when it was new. The study shows that increase in composite wear index more than 50% indicates severe damage to the endodontic file. This metrology-based framework highlights how integrated sensing, feature engineering, and condition-index formulation can support evidence-based file replacement decisions and enable predictive maintenance strategies for rotary endodontic instruments. © The Author(s), under exclusive licence to Metrology Society of India 2026. Thu, 01 Jan 2026 00:00:00 GMT https://dspace.iiti.ac.in:8080/jspui/handle/123456789/18846 2026-01-01T00:00:00Z https://dspace.iiti.ac.in:8080/jspui/handle/123456789/18815 Title: Analysis of Ramming Process for 155 mm×52 Caliber Gun Barrel System Authors: Upkare, Piyush Pradip; Chorma, Sumit; Dadhich, Ramanand; Singh, Indrasen Abstract: The interaction between rotating band and barrel during the ramming and engraving process influences the performance of gun. Several studies for the latter process have been reported, while studies for the former are limited to a few gun systems, including 152 mm mod 77, 125 mm T-72 tank, 125 mm 2A46 tank, and have not undertaken for 155 mm×52 caliber gun. Therefore, finite element simulations of ramming process have been performed for new and worn-out barrel of 155 mm×52 caliber gun system. The effect of leading angle of band on the contact force is also studied. Results show that ramming velocity Vr of 5 m/s generates enough contact force to avoid the fallback of projectile for maximum angle of barrel-elevation. Also, contact force drops gradually as barrel wear increases till 0.5 %, but drops rapidly for further enhancement in barrel wear. The minimum Vr ensuring no fallback in a worn barrel increases marginally up to 1 % barrel-wear, but it increases exponentially for further rise in barrel wear. Further, the driving band with a leading angle of 3° is found to produce maximum contact pressure. The results obtained from this study would help in understanding the ramming process better for the 155mm × 52 mm Caliber gun. © 2026, DESIDOC. Thu, 01 Jan 2026 00:00:00 GMT https://dspace.iiti.ac.in:8080/jspui/handle/123456789/18815 2026-01-01T00:00:00Z https://dspace.iiti.ac.in:8080/jspui/handle/123456789/18791 Title: Effect of standoff distance on the mechanical and biological behaviors of seashell-derived hydroxyapatite coatings deposited on Ti-alloy plates by flame spraying Authors: Kumar, Ashok; Suman, Setu; Sabiruddin, Kazi Abstract: This work investigates the effect of standoff distance (SOD) on the mechanical and biological properties of hydroxyapatite (HA) coating deposited on Ti-6Al-4 V substrates by spraying seashell-derived HA powder using flame spraying. The results are compared with the coating obtained by spraying phase-pure commercial HA powder. The SOD varies from 80 to 120 mm to obtain successful coatings, which are characterized by microstructure, phase composition, surface roughness (Ra), porosity, adhesion strength, fracture toughness, wear resistance, and in-vitro biocompatibility in simulated body fluid (SBF). The stable and metastable HAs, with TCP phase, are formed in the synthesized coatings, whereas only the stable HA phase is formed in commercial HA. The lower SOD of 80 mm has enabled the deposition of well-spread splats, which have reduced the surface roughness and porosity of the coating, thereby improving coating adhesion. It also shows the highest fracture toughness, hardness, and wear resistance among all synthesized HA. However, commercial HA with high crystallinity shows better tribo-mechanical properties than the synthesized HA. In contrast, the biocompatibility of seashell-derived HA is much higher than that of commercial HA. Coating porosity and metastable/TCP phases play crucial roles in apatite growth. Therefore, seashell-derived HA from SOD of 120 mm shows remarkably high biocompatibility with fast apatite growth. For improved mechanical properties, lower SOD may be preferred for HA deposition, whereas for enhanced biocompatibility, higher SOD should be chosen. Commercial HA may be a great choice for mechanical applications, but seashell-derived HA can be a better choice for biological applications. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2026. Thu, 01 Jan 2026 00:00:00 GMT https://dspace.iiti.ac.in:8080/jspui/handle/123456789/18791 2026-01-01T00:00:00Z