Transactions of The Indian Institute of Metals最新文献

Ti65 is a novel high-temperature titanium alloy tailored for use in the 650 °C temperature range. Its processing difficulties present substantial challenges to conventional manufacturing methods, compelling an exploration of alternative techniques. This study adopts laser additive manufacturing to join V-grooved Ti65 alloy specimens, thoroughly examining their microstructure and mechanical aptitude. Ultrasonic testing underscores the 90 ° V-groove’s integrity, showing no signs of porosity or unfused anomalies. Microstructural analysis reveals a distinct α lamellar configuration throughout the junction region, interface, and base matrix, accompanied by the emergence of Ti₃Sn and Si₃Ti₂Zr₃ silicide phases. Tensile assays conducted at room temperature suggest the V-groove connections outperform the additive-manufactured Ti65 alloy in strength. Contrarily, at elevated temperatures of 650 °C, the tensile strength surpasses that in the vertical orientation yet falls short of the horizontal, with notable declines in both fracture elongation and sectional contraction relative to the additive counterparts. Although there is a decrement in endurance strength, the material shows a promising creep resistance.

This paper explores the reasons for the perforation failure of the shale gas gathering pipeline in the E Gas Mine and proposes preventive measures. EDS experiment found that the corrosion products were mainly Fe₂O₃, FeS, and FeCO₃. Shale gas contains 24.908 g/m³ CO₂ and 0.384 g/m³ H₂S, and formation water contains 20.445 g/m³ Cl⁻. Therefore, CO₂/H₂S corrosion has occurred in the pipeline, and Cl⁻ exacerbated localized damage to the material matrix, accelerated corrosion of the pipeline. The base material was more corrosion resistant than the weld, but the weld was more erosion resistant than the base material. The CFD simulation results found that the main reason of pipeline erosion is that, the shale gas contains grit and the gas volume exceeds the designed gas volume. So, the perforation failure of the pipeline was a result of both corrosion and erosion, and the effect of erosion is stronger than that of CO₂/H₂S corrosion on the pipeline.

To examine the impact of the composite region temperature on the interface microstructure of AZ31B/6061 layered composites, while solid–liquid phase casting, we analyzed the temperature field during the preparation process. Subsequently, we carried out testing for microstructure characterization and mechanical properties. It was determined that a composite interface temperature below 620 ℃ leads to the formation of a diffusion region dominated by one-way diffusion and interface reaction of Al atoms. When the temperature of the composite interface exceeds 630 ℃, a mixed liquid of Mg and Al forms, promoting the diffusion and collision of diatoms and causing violent convective diffusion and thermal diffusion reactions. This leads to the formation of composite layers and composite regions. Temperature parameters significantly impact the casting of Mg/Al laminated composites, primarily through factors such as thermal stress and deformation, element diffusion rate and distance, and interface reaction. When controlling the casting temperature at 720 ± 10 ℃ and the regional temperature at 630 ± 10 ℃, the Mg/Al laminated composite with the most optimal composite effect can be prepared. It is important to maintain this temperature range in order to achieve the desired result.

In this review article, we have compiled state-of-the-art recent hydrometallurgical processes used to recover metals from spent lithium-ion batteries. The composition of lithium-ion batteries has evolved over time to fulfil the demand for storage capacity. Similarly, metal recovery and recycling strategies have evolved due to compositional changes and technological advancement. Traditional inorganic and organic acid leaching has various merits and limitations. Recent research has focused on creating enhanced leaching methods that incorporate cutting-edge techniques such as electrochemical, ultrasonic, and oxidative leaching. Alkaline, ammoniacal, and mechanochemical leaching have all been explored as pre-treatment methods. We have presented brief overviews on prospects of water leaching and combination of pyro-hydrometallurgical reduction roasting and leaching. Finally, we discussed the difficulties in the recovery process caused by the constantly changing compositions of next-generation batteries because of various factors. A data analytics-based framework is proposed as a promising solution for capturing and explaining the effects of various parameters by leveraging historical data to optimise process conditions.

Titanium oxide pigment industries produce a large amount of undissolved particles called sludge during the sulfate process of ilmenite. The sludge mainly constituted 48% TiO₂, 15% SiO₂, 11% Fe₂O₃, 4.5% SO₃, and 2% Al₂O₃. Zirconium, vanadium, magnesium, and calcium oxides are also in small amounts. The presence of sulfur induces an acidic nature to the sludge and reduces its further utilization. Using a simultaneous process to reduce sulfur content and extract important metals is crucial. The paper describes use of acidic sludge to extract titanium to prepare titanium rich alloy. The method involves initial neutralization and reduction roasting followed by magnetic separation. The separated magnetic part was then utilized for aluminothermic reduction by smelting, resulting in titanium-rich alloy. Analytical techniques such as XRD, SEM–EDS and Thermal analysis were conducted during the studies. Titanium-rich alloys having a composition of ~ 51.8% Ti, 22.4% Al, 9.5% Si, and 16.3% Fe were achieved.

Graphical Abstract

Duplex stainless steel (DSS) 2205 finds wide application in aircraft industries and for surgical implants. However, the formability of 2205 steel sheets is limited under normal conditions, requiring hot-working to enhance strain hardening at lower temperatures. Furthermore, there is a lack of research on the single point incremental forming process (SPIFP) applied to DSS 2205. Hence, the current study aims to explore the fracture characteristics of 2205 steel sheets using SPIFP, while varying several parameters such as tool type, tool diameter, speed, feed rate, and vertical step down. Optimal process parameter selection holds significant importance due to its potential for cost reduction and enhancement of quality. This choice involves determining suitable process parameters while considering multiple conflicting factors, necessitating the application of the multiple criteria decision-making (MCDM) approach. Hence, this work addresses the MCDM challenge using the additive ratio assessment (ARAS) and complex proportional assessment (COPRAS) techniques. The experiment carried out with two different forming tools such as hemispherical-ended forming tool and ball-ended forming tool, assessment carried out by varying the stated independent parameters. The dependent parameters include straight groove depth, wall angle depth, spring back, formability, and surface roughness. The SPIFP alternatives are assessed using the aforementioned two techniques, and the outcomes are subsequently analyzed. The best possible arrangement was determined using ARAS and COPRAS methods to achieve both maximum and minimum values for all the responses. This arrangement was identified with the hemispherical-ended forming tool and the specific set of process parameters: a tool diameter of 10 mm, a feed rate of 600 mm/min, a speed of 200 rpm, and a vertical step down of 0.6 mm. In 77.78% of instances, the rankings from ARAS are in agreement with the rankings from COPRAS. Notably, the lower and higher orders of rankings are the same, adding an intriguing dimension to the observation. However, the patterns of different dependent variables, influenced by the diversity of independent variables, were not consistent. These intricate mechanisms have been recognized and documented.

The study investigates the impact of powder metallurgical factors on the corrosion rate (CR) of biodegradable zinc (Zn)-hydroxyapatite (HAP) materials. Factors such as HAP weight percentage (wt%), compaction pressure (CP), heating rate (HR), sintering temperature (ST), and dwell time (DT) were examined. Static immersion test was performed to determine the CR of the samples. The results showed an increase in CR with increased HAP wt%, while factors like CP, HR, and ST led to lower CR. The CR decreased with an increase in DT upto 18 min and thereafter increased. HAP wt% was found to be the most significant factor, contributing 57.95% on CR. A genetic algorithm-based optimization was conducted to minimize CR of Zn-HAP materials. The experimental CR value obtained at optimized levels, i.e., 3 wt% HAP, 34 MPa CP, 25 °C/min HR, 480 °C ST, and 30 min DT, were found to be 0.121 mm/yr, which was within the range of the predicted value 0.08 ± 0.044 mm/yr. This work presents a statistical modeling approach for predicting the CR of Zn-HAP composite for biomedical applications.

Traditional IN-718 superalloy inspires the novel AlCrFeMoNbNi high-entropy alloy developed in this work. Major constituents of the IN-718 are selected in equiatomic proportions and processed via vacuum arc melting route. Alloy in the as-cast and heat-treated (1373 K for 24 h and 1373 K for 24 h + 1473 K for 48 h) conditions showed a multi-phase structure (BCC1, B2, Sigma, and BCC2) with high hardness of 11.94–9.08 GPa at indentation loads of 25–5000 g. Further, a significant indentation size effect (ISE) has been observed, which was confirmed by the Meyer’s power law. Strain gradient plasticity theory based on geometrically necessary dislocations, proposed by Nix and Gao, was adapted to understand the ISE. Further, depth-independent hardness values of 9.30 ± 0.9, 9.26 ± 0.9, and 10.41 ± 0.9 GPa and characteristic length scales of 0.52 ± 0.01, 0.53 ± 0.01, and 0.25 ± 0.02 µm were evaluated at different processing conditions in the current work. At 5000 g. load, K_IFT values (in MPa (sqrt m )) of 4.68, 6.61 and 6.29 were realized for as-cast, single heat-treated and double heat-treated conditions respectively.

X-ray diffraction detailed analysis of nitrogen-added austenitic 316LN stainless steels with different nitrogen concentrations (0.07, 0.11, 0.14, 0.22 wt.%) was carried out in creep-tested (at 923 K, 200 MPa) and solution-annealed conditions. The effect of nitrogen on lattice parameter was studied before and after creep testing. Size and strain were estimated through Williamson–Hall analysis. High nitrogen-added 316LNSS showed lower dislocation density. Increase in creep rupture lifetime with nitrogen content correlated well with the lattice parameter, crystallite size, and strain.

The electromagnetic frequency high-energy stir casting process was used to create the high-quality magnesium (Mg) dispersed with varied percentages of nano-sized B₄C (0, 0.5, 1 and 1.5 wt%). The shape and distribution of Mg with nano B₄C were validated by characterization research on nanocomposites utilizing energy-dispersive spectrum, scanning electron microscope and X-ray diffraction. Thermal and mechanical characteristics such as thermogravimetric analysis/differential thermal analysis and tensile strength were explored utilizing acoustic emission. During a tensile test, online monitoring using acoustic emission (AE) demonstrates a reduction in fracture development and propagation. The tensile test result exhibits that, Mg-1.5% B₄C nanocomposite has a better tensile strength (σ_ultimate = 125 MPa) than the Mg-0.5% B₄C nanocomposite (σ_ultimate = 115 MPa). AE results show that the hit begins at 26 µs for Mg-1.5% B₄C nanocomposite, whereas for Mg-0.5% B₄C nanocomposite, it begins at 14 µs. Thus, AE results show that an increase in B₄C nanoparticles in the composites will prevent hits from occurring. The SEM and atomic force microscopy analyses were performed on the tensile-tested specimens to find the distinguishing characteristics. Owing to the inclusion of the B₄C, the Mg-1.5% nano B₄C composite has a longer ignition time in the thermogram of TGA and greater tensile strength than the Mg.