Changes In Hardness Research Articles

Microstructural constituents in compositionally graded NiCrFeSiBC hardfacing alloy/316L SS additive manufactured deposits

Ni-Cr-Fe-Si-B-C hardfacing alloys (D50) provide excellent resistance to abrasive and adhesive wear, high temperature oxidation and corrosion. These alloys are candidate materials for hardface coatings on in-reactor components of fast breeder reactors. Conventionally these deposits are made on steels through the welding route. Due to high fluidity of the molten alloy, generation of residual stress and significant dilution of the deposit, achieving crack free deposits is often a very difficult and time consuming task. To address such issues arising out of conventional fabrication routes, compositionally graded coatings have been tried through laser additive manufacturing. A 3 layered compositionally graded deposit (D50/50D50-50SS/SS) was made on 316 L SS build plate and the phase constituents and possible correlation with micro hardness was analyzed. Uppermost D50 layer consisted of γ-Ni, γ-Ni + Ni3B and γ-Ni + Cr5B3 eutectics, CrB, Cr7C3, Cr23C6, Cr3C2 and Ni3Si precipitates. The middle layer consisted of γ-(Ni,Fe), γ-(Ni,Fe)+Cr5B3, Cr5B3, Cr3C2, Cr7C3,Cr23C6 and Ni3Si. The SS layer closest to the build plate had γ-Fe, Cr3C2 and Cr7C3 precipitates. Corresponding to the variation in microstructure a gradual change in hardness also can be seen starting from the top layer to SS build plate: 580 ± 35 HV0.1, 532 ± 17 HV0.1, 348 ± 21 HV0.1 and 230 ± 10 HV0.1, which is promising.

Effect of High-Pressure Processing Treatment on the Physicochemical Properties and Volatile Flavor of Mercenaria mercenaria Meat.

High-pressure processing (HPP) technology can significantly improve the texture and flavor of Mercenaria mercenaria. This study aimed to investigate the effect of HPP treatment with varying levels of pressure (100, 200, 300, 400, 500, and 600 MPa) and a holding time of 8 min at 20 °C on the physicochemical properties and volatile flavors of M. mercenaria. The significant changes in hardness, resilience, and water holding capacity occurred with increasing pressure (p < 0.05), resulting in improved meat quality. Scanning electron microscopy (SEM) was utilized to observe the decomposition of muscle fibers in M. mercenaria due to varying pressures, which explains the differences in texture of M. mercenaria. Different pressure treatments also had an influence on the volatile flavor of M. mercenaria, and the quantities of low-molecular-weight aldehydes (hexanal, heptanal, and nonanal) with a fishy taste decreased dramatically following 400 and 500 MPa HPP treatments. Furthermore, the level of 2-Methylbutyraldehyde, which is related to sweetness, increased significantly following 400 MPa HPP treatment. The study found that 400 MPa HPP treatment resulted in minor nutrient losses and enhanced sensory quality. The results of this study provide a theoretical basis for the application of HPP treatment to M. mercenaria.

Experiments on High-Temperature Irradiation of Li2ZrO3/MgLi2ZrO4 Ceramics by He2+ Ions

The key objective of this study is to determine the effect of interphase boundaries, the formation of which is caused by the variation of Li2ZrO3/MgLi2ZrO4 phases in lithium-containing ceramics based on lithium metazirconate, on the resistance to near-surface layer destruction processes associated with irradiation with He2+ ions. During the observation of the deformation effects that have an adverse impact on the volumetric swelling of the near-surface layers of ceramics, the thermal expansion factor caused by high-temperature irradiation was considered, simulating conditions as close as possible to the operating conditions of these materials as blankets for tritium propagation. During the studies conducted, it was established that an elevation in the contribution of MgLi2ZrO4 in the composition of ceramics leads to a rise in resistance to deformation swelling caused by structural distortions of the crystal lattice, due to a decrease in the effect of thermal expansion, alongside the presence of interphase boundaries. The established dependencies of the change in the hardness of the near-surface layer of the studied ceramics made it possible to establish the kinetics of softening caused by the deformation distortion of the crystalline structure, as well as to determine the relationship between volumetric swelling and softening (change in hardness) and a decrease in crack resistance (change in the value of resistance to single compression).

Effects of electrical and mechanical properties of Ba0.92Ca0.08Zr0.05Ti0.95O3 ceramics with lanthanum dopants

Element doping is one of the important approaches to improve the performance of lead-free piezoelectric ceramics. In this study, Ba0·92Ca0·08Zr0·05Ti0·95O3-xLa (BCZT-xLa) piezoelectric ceramics were prepared by sol–gel method. The effects of La3+ contents on the phase structure, mechanical properties, and electrical properties of BCZT-xLa ceramics were investigated. Results showed that La3+ could affect the properties of ceramics by adjusting the concentration of oxygen vacancies and microstructure. When the La3+ contents were 0.008, the ceramics showed the best performance (the maximum permittivity was 8736.27, the remnant polarisation was 9.69 μC/cm2 and the coercive field was 3.44 kV/cm). The influences of Vickers hardness on ceramics were investigated using various La3+ contents. The lattice energy and oxygen vacancies were the main factors for the change in Vickers hardness. With an increment of x, the Vickers hardness values decreased from 6.271 GPa to 1.438 GPa. This study could provide a reference for BCZT piezoelectric ceramics doped with rare earth elements.

N-[(1RS)-Camphan-2-ylidene]-4-ethoxyaniline and its reduction product as stabilizers of nitrile butadiene rubbers

Objectives. To investigate the protective efficacy of unreduced and reduced forms of the condensation product of D,L-camphor and p-ethoxyaniline in nitrile butadiene rubber formulations when compared with the conventional stabilizer N-isopropyl-N′-phenyl- p-phenylenediamine aged under laboratory and in situ climatic conditions in the tropics.Methods. The thermostabilizing effect of the condensation product of D,L-camphor and p-ethoxyaniline was evaluated by means of infrared spectroscopy using the dynamics of changes in the absorption bands of carbonyl and hydroxyl groups. The features of rubber vulcanization were studied by means of rotorless rheometry. Changes in the physical and mechanical properties of rubbers and degree of cross-linking were evaluated after thermo-oxidative aging in laboratory conditions. They also took into account the results of longterm exposure of samples in undeformed and deformed state in a tropical climate, taking into account meteorological data of the Can Gio climatic testing station.Results. It was found for the first time that condensation products of D,L-camphor and p-ethoxyaniline exhibit a stabilizing effect in formulations of rubbers based on polar nitrile butadiene rubber.Conclusions. According to the results of laboratory and in situ tests, the study established that the use of N-[(1RS,2RS)-camphan-2-yl]- 4-ethoxyaniline (reduced form) as an antifatigue agent is preferable. This is due to the presence of a mobile hydrogen atom at the nitrogen atom. The protective effect is manifested in terms of the better preservation of elastic-strength properties of rubbers with less change in hardness.

Study on the UV aging resistance of ZnO‐modified epoxy resin by experiments and MD simulation

AbstractThis study investigates the impact of zinc oxide nanoparticles on epoxy resin systems and the ultraviolet (UV) aging resistance of modified epoxy resin composites using molecular dynamics (MD) simulations and experimental methods. Initially, various epoxy resin cross‐linking models are established through MD simulations to understand the influence of different nano ZnO contents on resin modification, further validated by experiments. Subsequently, the UV radiation resistance of nano ZnO–epoxy resin composites is assessed by subjecting them to high‐intensity UV radiation equivalent to 3 years of natural environmental conditions, analyzing changes in tensile properties, impact performance, hardness, and glass transition temperature of epoxy resin before and after UV radiation exposure. The findings suggest that the addition of nano zinc oxide reduces the impact of UV radiation on epoxy resin, with optimal UV radiation resistance observed at a nano zinc oxide mass fraction of 0.3 wt%.

Evaluating the protective effects of mouthguards with neutralizing agents against chlorinated water-induced enamel erosion.

Dental erosion is a common problem among swimmers. This study evaluated the effects of mouthguard use with or without neutralizing agents, compared to no mouthguard use, on the microhardness of dental enamel after a swimming simulation. Ninety-six human premolars were randomly allocated into six groups of 16 each: Group A (no mouthguard), Group B (mouthguard only), Group C (mouthguard with fluoride toothpaste), Group D (mouthguard with fluoride-free toothpaste), Group E (mouthguard with CPP-ACP), and Group F (mouthguard with arginine-fluoride toothpaste). Enamel slabs were fixed in a wax model (Typodont Articulator) and used to fabricate mouthguards for all groups except Group A. Each specimen underwent cyclic immersion: 2 h in acidic chlorinated water (pH 3.1) followed by 22 h in artificial saliva, for 28 days, to simulate swimming exposure. The change in enamel surface hardness was measured using a Vickers hardness tester. All groups underwent microhardness testing, scanning electron microscopy, and polarized light microscopy. The enamel hardness significantly decreased in all groups after the swimming simulation (paired t-test, P-values < 0.001), except for Group F, which used a mouthguard with arginine-fluoride toothpaste [mean reduction: 17.9 kg/mm2, 95% confidence interval (CI): -1.9, 37.7, P-value = 0.07]. Group A, without a mouthguard, exhibited the highest reduction in enamel surface hardness (mean: 190.6 kg/mm2; 95%CI: 177.4, 203.9), significantly differing from all other groups with mouthguards (P-values < 0.001). However, no statistically significant differences were observed in enamel hardness reduction among the mouthguard groups. SEM micrographs illustrated rough, irregular erosion patterns and several deep porous areas on enamel surfaces of Group A. In contrast, all mouthguard groups showed enamel surfaces similar to sound tooth surfaces. A polarized light microscopic study revealed the deepest dark areas on the enamel surface of Group A. Mouthguards significantly reduced enamel microhardness loss compared to no mouthguard use. While no significant differences were found among mouthguard groups with or without neutralizing agents, those lined with arginine-fluoride toothpaste showed the least enamel loss, suggesting its potential protective effect. Within the limitations of this in vitro study, further clinical trials are needed to validate these results.

Clinical and Radiographic Evaluation of Soft Tissue and Bone Status in Immediate Loaded Implants Placed Following Their Extraction in the Maxillary Anterior Region.

In the maxillary anterior region, teeth extraction leads to significant soft and hard tissue changes. Immediate implant placement following extraction aims to reduce bone loss and overall treatment time. However, it may result in adverse soft tissue changes impacting esthetics. This study evaluates the clinical and radiographic outcomes of immediately loaded implants in the maxillary anterior region, focusing on soft tissue preservation and bone status. This study, conducted from April 2022 to August 2024 at the Department of Oral and Maxillofacial Surgery, Ragas Dental College and Hospital, included 10 immediately loaded implants in seven patients. Following atraumatic extraction, implants were placed and loaded with functional provisional crowns fabricated using three-dimensional (3D) rapid prototyping models. Parameters such as crestal bone loss, buccal and palatal bone width, and interdental papilla thickness were evaluated preoperatively and postoperatively using radiographsand clinical assessments. The study found significant crestal bone loss at both mesial and distal sites over time, with the greatest loss observed at the three-month follow-up. Buccal and palatal bone width showed no significant differences preoperatively and postoperatively. Interdental papilla thickness and overall pink esthetic scores also showed no significant differences between preoperative and postoperative evaluations. Immediate implant placement in the maxillary anterior region, using 3D rapid prototyping for custom splint fabrication, demonstrated effective preservation of soft tissue profile and bone architecture. This approach provides functional and esthetic benefits, although careful monitoring of crestal bone loss is necessary.

Mechanical and metallurgical properties of a glass fiber-reinforced Al7075 hybrid composite produced by infiltration and after aging and abrasion

Abstract Within the scope of this study, composite structures were produced by reinforcing Al7075 with 6 mm size glass fiber (GF) scrap at different weight rates (2–3 %) using the infiltration method. Mechanical and metallurgical examination of unreinforced Al7075 samples and reinforced Al7075 composite samples were carried out. After the aging heat treatment of the samples, pin-on-disc wear and hardness tests were performed. FESEM and EDS analyses were conducted to examine the hardness and microstructural changes caused by the applied processes on the samples. It was observed that GF reinforcement increased the hardness of the material and there was full wettability between Al 7075 and GF. Thus, wear resistance increased. The highest hardness and wear resistance were obtained in the 6 h aged 2 wt.% GF-reinforced Al 7075 matrix hybrid composite sample. In addition, it was observed that the distribution of GF scrap added as reinforcement at a rate of 2 wt.% in Al 7075 was homogeneous, and the hardness measurements taken from different areas were similar.

Postweld Heat Treatment of 15Cr-6Ni-2Mo-1Cu Supermartensitic Stainless Steel Welds

Supermartensitic stainless steels with 15Cr-6Ni- 2Mo-1Cu and 135 ksi minimum yield strength (15Cr- 135 SMSS) offer high strength and good toughness through a complex hierarchical microstructure of nanoscale precipitates, tempered martensite, and reverted austenite. Upon welding and postweld heat treatment, substantial changes to heat-affected zone microstructure and hardness may occur. Here, we reveal spatially heterogeneous microstructure and microhardness in the HAZ of 15Cr-135 SMSS; correlate these changes to measured phase transformation temperatures; and demonstrate that HAZ hardness changes depend strongly on postweld heat treatment (PWHT) temperatures. Furthermore, we demonstrate that PWHT may lead to undesired reductions in base metal yield strength and formulate a design guide for PWHT that quantifies the trade-offs in desired reductions of HAZ hardness with undesired changes to base metal yield strength. These findings have important practical implications for welding procedure design and qualification.

Service performance of nitrile rubber sealing ring under 70 MPa high-pressure hydrogen

Abstract The service performance of NBR seals under 70 MPa high-pressure hydrogen was investigated, and the effects of vulcanization additives, fillers, and crude systems on their sealing performance were investigated. The sealing performance was characterized by the changes in volume and hardness before and after the service of the seals.

The microhardness, morphology and tribological property of TC4 subjected to machine hammer peening

Ti alloy has become an indispensable material in harsh working environments due to its excellent wear resistance, corrosion resistance and impact resistance. These environments place stringent requirements on the fatigue life, friction and wear, and surface strength of materials. Therefore, this study aims to deeply explore the surface mechanical properties of Ti-6Al-4V (TC4) alloy after machine hammer peening (MHP) treatment. By conducting experiments on TC4 alloys treated with different hammering energies, the changes in surface hardness, morphology, roughness, tensile properties, and friction properties were analyzed, and the strengthening mechanism of MHP was discussed. Experimental results show that MHP treatment can effectively improve the surface properties of TC4. With the increase of hammer energy, due to the double-sided hammering of the plate, the microhardness first increases, then decreases, and then rises again. The tensile strength and yield strength of the sample increase slightly, but the elongation at break decreases. The surface roughness of the sample increases first and then decreases. Similarly, after MHP treatment, the wear resistance of the samples increased, the friction coefficient decreased, and the wear amount and surface height difference showed a trend of first increasing and then decreasing. The wear mechanism mainly included adhesive wear, abrasive wear and fatigue wear.

Electro-Mechanical Behavior of Copper-Based Electrical Motor Brushes

This study was mainly performed in order to examine the properties of electric motor brushes (EMB). EMBs are electrically conductive and work under wear conditions due to direct contact with the moving part (rotor) of electric motors. In accordance with the scope of the study, EMB characteristics were investigated in two different groups and reproduced with a new technique at the end of this phase. New EMBs were produced via varying proportions of copper matrix, graphene, and silicon carbide reinforcements. The composite-alloy powder elements were carefully squeezed by a cold and single-axis hydraulic press under a pressure of 500 MPa (±5 MPa) following 8 hours of mechanical alloying (MA). The molded composite product (sample) was sintered at 900° C for 1 hour in a reducing gas atmosphere. 100 kPa spring pressure was tested on each sample thrice with 8, 16, 24, and 32 m/s rotational speeds and densities of 4, 8, 12, and 16 A/cm2. Following this process, the electrical conductivity, porosity, hardness, wear loss, surface roughness, and temperature changes were investigated for each sample. It was determined that the electrical conductivity decreased with increasing reinforcement ratio and, in terms of electrical conductivity, affected the brushes’ properties negatively.

Influence of Mg Content on Microstructure Coarsening, Molten Pool Size, and Hardness of Laser Remelted Al(-x)-Mg-Sc Alloys.

Investigations leading to high-quality surfaces and optimized properties in laser remelted Al-Mg-Sc alloys remain scarce. Laser surface remelting (LSR) has been used for the final treatment of these alloys processed through additive manufacturing. However, the direct microstructure responses of the treated cast surfaces have not yet been investigated. In the present research, Al-3, 5, and 10 wt %-Mg-0.1 wt %-Sc alloys plates were processed using LSR to study the effects of local melting and rapid solidification. The morphology of the α-Al phase, microstructure coarsening, and hardness were mapped from the bottom to the top of the molten pools, varying with local Mg content and laser heat input (2.5 J/mm, 5 J/mm, and 10 J/mm). This study aimed to create a comprehensive map of the microstructures, hardness, and molten pool sizes under various conditions. The findings may help to optimize these alloys through understanding laser processing parameters. Methods used included CALPHAD computations, optical microscopy, SEM, EDS, image analysis, hardness tests, and heat flow models. The results obtained showed α-Al cell growth with bands in all alloys with hardness changes correlating with cell spacing and heat input. Higher Mg content resulted in more refined cells and a higher fraction of bands. Increased Mg content decreased the thermal diffusivity and enthalpy of melting, enlarging the molten pool size. Hardness increased with decreasing heat input and higher Mg content in the tested alloys, especially in the Al-10 wt %-Mg-0.1 wt %-Sc alloy as the heat input was varied.

Changes in Surface Topography and Light Load Hardness in Thrust Bearings as a Reason for Tribo-Electric Loads

The article focuses on the findings of endurance tests on thrust bearings. In addition to the mechanical load (axial load: 10 ≤ C0/P ≤ 19, lubrication gap: 0.33 µm ≤ h0 ≤ 1.23 µm), these bearings are also exposed to electrical loads (voltage: 20 Vpp ≤ U0 ≤ 60 Vpp, frequency 5 kHz and 20 kHz), such as those generated by modern frequency converters. In a previous study, the focus was on the chemical change in the lubricant and the resulting wear particles. In contrast, this article focuses on the changes occurring in the metallic contact partners. Therefore, the changes in the surface topography are analysed using Abbott–Firestone curves. These findings show that tests with an additional electrical load lead to a significant reduction in roughness peaks. A correlation to acceleration measurements is performed. Moreover, it is shown that the electrical load possibly has an effect on the light load hardness. An increase in the occurring wear could not be detected during the test series. Also, a comparison with mechanical reference tests is made. The article finally provides an overview of different measurement values and their sensitivity to additional electrical loads in roller bearings.

Surface quality enhancement in ultrasonic vibration-assisted electrochemical machining

The aviation industry's evolution has introduced electrochemical machining (ECM) as a promising non-traditional technology for aero-engine blades. However, the surface quality of challenging-to-cut materials is compromised due to insoluble electrolytic products on the machined surface. To enhance ECM's surface quality, ultrasonic-assisted ECM (UA-ECM) was introduced for effective electrolytic product removal. This study conducted numerical simulations involving coupled flow field and cavitation models. It also performed observation experiments and a series of UA-ECM trials with varying inlet pressures (0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, and 0.5 MPa), vibration amplitudes (21 µm, 17 µm, 13 µm, 8 µm, 4 µm, and 0 µm), and current densities (31.9 A/cm2, 42.1 A/cm2, 61.1 A/cm2, 76 A/cm2, and 100.9 A/cm2). These aimed to elucidate the mechanism of tool ultrasonic vibration's influence on surface quality and corroborate the simulation findings. Notably, under conditions of low inlet pressure (0.1 MPa), high vibration amplitude (21 µm), and high current density (100.9 A/cm2), complete removal of electrolytic products, inhibition of pitting defects, and attainment of a mirror surface with a surface roughness of Ra = 0.14 µm were achieved, with no change in hardness. This clearly demonstrates that the surface quality of ECM on complex surfaces can be significantly enhanced by ultrasonic assistance.

Hardness changing tactile displays for simulating the feel of organic tissues.

Physical interaction with patients, for example conducted as part of a diagnostic examination or surgical procedure, provides clinicians with a wealth of information about their condition. Simulating this interaction is of great interest to researchers in both haptics and medical education, and the development of softness changing tactile interfaces is important in recreating the feel of different soft tissues. This paper presents designs for a variety of novel electromechanical and electromagnetic mechanisms for controlling particle jamming-based, hardness changing tactile displays, intended to allow medical trainees to experience these physical interactions in a range of simulation settings such as clinical skills teaching laboratories. Each design is then subjected to a battery of mechanical tests to evaluate its effectiveness compared to the state of the art, as well as their suitability for simulating the physical hardness of different types of soft tissues, previously characterised in established literature. These results demonstrate that all of the technologies presented are able to exhibit a measurable hardness change, with Shore hardness values between 3A and 57A achieved by the most effective constriction-based device. The electromechanical devices based on constriction and compression, and the state-of-the-art pneumatic device, were able to achieve hardness changes within a range that is useful for replicating the softness of organic tissue. The electromechanical and electromagnetic devices were also found to effect their full range of hardness change in less than a second, compared to several seconds for the state-of-the-art. These results show that the performance of softness changing tactile displays can be improved with the electromechanical actuation techniques proposed in this paper, and that such displays are able to replicate the physical characteristics of soft tissues and may therefore be of benefit in medical training and simulation scenarios.

Effects of four types of packaging on the structural characteristics, quality attributes, and antioxidant activity of foxtail millet during storage

ABSTRACT The aim of this study is to select suitable packaging for extending the shelf-life of foxtail millet grains (FMG). FMG were packaged in four types of packaging and subsequently stored at room temperature (25°C ± 1°C) for 6 months. The effects of four types of packaging on the corresponding structural characteristics, quality attributes, and antioxidant activity of FMG were investigated. The results showed that aging led to less-prominent internal morphological changes with the vacuum- and N2-packaged samples. Moreover, vacuum and N2 packaging retarded the increase of fat acidity and the decrease of yellowness (b*) during storage. Aging in cotton and polyamide–polyethylene (PA/PE) packaging resulted in less soluble solids leakage during cooking, leading to more reduction in stickiness. No changes in hardness of cooked FMG were found only for vacuum packaging. In addition, total phenolic content and antioxidant capacities were well preserved under vacuum or N2 conditions. Overall, vacuum packaging was more effective in retarding the quality deterioration of FMG when compared to the other storage conditions.

The Influence of Cryogenic Treatment on the Tribological Properties of Tungsten Carbide

Improvement in wear resistance and hardness of cutting tool material is one of the most critical challenges in machining operations. This issue can be addressed by enhancing wear resistance and hardness through cryogenic treatment of tungsten carbide. This study investigates the effect of different soaking periods during cryogenic treatment on commercially available tungsten carbide. Experiments were conducted at a temperature of 88K with varying soaking periods of 8 hours, 20 hours, 24 hours, and 30 hours. To quantify and confirm the impact of different soaking periods on hardness and wear resistance, Rockwell hardness measurements and weight loss during wear tests were performed. The results indicate a significant decrease in weight loss for the sample soaked for 8 hours compared to other soaking periods, although there was no change in bulk hardness. The reduced weight loss during the sliding wear test suggests that cryogenically treated tungsten carbide exhibits improved wear resistance due to an increased population density of carbides. Microstructural analysis of the worn surface reveals the mechanism behind the enhanced mechanical properties. Key Words: Cryogenics, dct, sct, microstructure, soaking period, tool life.

The effects of beverage erosion on enamel: evaluating surface characteristics and loss of calcium and phosphate ions

BackgroundThe erosive impacts of various beverages on dental enamel have been identified as a potential erosive threat to dental hard tissues. This in vitro study aimed to address this by utilizing a systematic approach and advanced analytical methods to study enamel erosion due to selected beverages in a simulated oral environment.MethodsForty-nine extracted sound second premolar teeth were collected, disinfected, and prepared. These teeth were randomly allocated into seven groups, each exposed to a different beverage: distilled water, mineral water, instant coffee, black tea, Pepsi-Cola, orange juice, and synthetic vinegar. The modified Nordini Artificial Model (mNAM) was used to simulate the oral cavity. The enamel surfaces were scanned using a Scanning Electron Microscope (SEM) and analyzed using Energy-Dispersive X-ray Spectroscopy (EDS). Surface hardness was measured using the Knoop Hardness Scale. Statistical analysis was conducted using the Wilcoxon signed-rank test, with a significance level set at p < 0.05.ResultsDistilled water and mineral water exhibited no significant changes in enamel surface or hardness. Coffee caused an 8–9% loss of calcium and phosphate, indicating potential erosion. Black tea showed signs of remineralization rather than demineralization. Pepsi-Cola and orange juice caused substantial erosion, with Pepsi-Cola resulting in a nearly 24% loss of calcium. Vinegar had a marked erosive effect, with a 17% loss of both calcium and phosphate. SEM images corroborated these findings, showing pronounced enamel prisms and increased visibility of minor cracks in post-treatment teeth. EDS analysis revealed significant changes in the elemental composition of the enamel.ConclusionsThis study categorised beverages based on their pH and fluoride content, revealing that drinks like Pepsi-Cola and orange juice are acidic but low in fluoride, whereas black tea, mineral water, and vinegar are acidic yet contain fluoride. The study suggests that the decrease in pH of acidic beverages may contribute to dental erosion, with fluoride as a mitigating factor. Among the various metrics assessed for evaluating dental erosion, hardness emerged as the most reliable quantitative parameter.