Solid Metal Research Articles

An Analytical Study for Explosive Grain Initiation

The most common form of solidification of metals is heterogeneous nucleation, in which the particles, regardless of whether they are endogenous or exogenous, nucleate the primary crystal phase, becoming solid crystal particles and, subsequently, initiating into grains during solidification. Explosive grain initiation has been proposed recently for these particles, which have significant nucleation undercooling, in which once nucleation happens, a certain number of solid particles can initiate into grains simultaneously, resulting in recalescence. This is a different form of grain initiation and has high potential for more significant grain refinement in casting alloys. In this work, an analytical model is designed to describe explosive grain initiation, based on which the criteria for the three different grain initiation forms, explosive grain initiation (EGI), hybrid grain initiation (HGI), and progressive grain initiation (PGI), are derived. These criteria are employed to develop a grain initiation map for the Mg-Al alloy system inoculated with nucleant particles having a log-normal size distribution. This work can not only help us to understand the effect of each condition, such as the cooling rate and the solute concentration, on grain initiation behaviors, but also predict the grain size for alloy systems with relatively impotent nucleant particles during solidification.

Design a Gating System for an Aluminum Cast Three-Way Pipe in Sand Casting

The study of aluminum casting work with market demand in the metal casting industry, designing a gating system in aluminum casting using a three-way pipe-shaped sand mold workpiece as a basic shape template in metal casting, namely a flat-face core box with a core. The gating system has a metal inlet with design variables including the pouring height, pouring basin cross-sectional area, rest basin cross-sectional area, running system cross-sectional area and inlet cross-sectional area. From the studying and designing, actual casting experiments were conducted and simulation behavior was analyzed using Cast-Designer software to make decisions and find appropriate design approaches from analyzing simulation results including liquid metal filling time, molten metal flow behavior, metal solidification time and shrinkage porosity formation of the workpiece. The results of the casting experiment and behavior simulation were able to cast the pipe workpiece which is a flat-face core box mold. The analysis results from the software can be used for actual pouring, where the fully cast mold successfully produced a complete workpiece. This can be a guideline for future improvements to reduce the shrinkage of actual cast workpieces.

Synthesis and characterization of new organometallic lanthanides metal complexes for photodynamic therapy

New Schiff base ligand: 4-methoxy salicaldhyde-2-2-phenyl-hydrazono acetaldehíyde prepared by facile method. The molecular structures characterized by elemental analysis and proton magnetic resonance spectra (1H-NMR spectra). This spectra at the chemical shifts (3.5–10.39 ppm) confirmed the types and the numbers of protons. The sharp melting point at the range 110–112 °C confirmed purity. New optically active metal (samarium, terbium and gadolinium) complexes of the Schiff base synthesized in a one pot reaction. Vibrational IR spectra confirmed functional groups. Scanning electron microscopy micrographs confirmed that the modified microstructure of the metal complexes differed in morphology than the ligand. Powder X-ray diffraction patterns confirmed good crystalline structure. The optically activity of the solid metal complexes confirmed from electronic absorption spectra. The UV absorbance band at the wavelength range 280–390 nm and the intense phosphorescence bands up to 830 nm enabled application in photo dynamic therapy for apoptosis cancer cells by conversion triplet oxygen in the tissues into reactive singlet oxygen. Low charge transfer energy: 2.59–2.61 eV, high molar extinction coefficients (ε) at the order of magnitude \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\:{10}^{6}$$\\end{document} M− 1 cm− 1 and the intense phosphorescence bands reflected good photodynamic activity. The metal complexes are thermally stable.

Single‐Crystalline LiMg Alloy Anode for Deep Cycling All Solid State Lithium Metal Batteries

AbstractAll solid state lithium metal batteries (ASSLMBs) with enhanced energy density has driven the exploration of Li‐alloy anodes such as Li‐Mg alloy owing to its solid‐solution structure and high theoretical specific capacity. But the Li atom diffusion limitation on Li‐Mg electrode surface further leads to sluggish atoms transport dynamics. Herein, single‐crystalline (110)‐oriented Li0.9Mg0.1 (denoted as LiMg(110)) anode is obtained by a tailored melt‐annealing procedure to tackle the above issues. Theoretical analyses and experimental results demonstrate that the crystallographic structural (110) orientation of LiMg anode can facilitate Li atom diffusion and guarantee the electrode stability during deep cycling. As a result, the LiMg(110) electrode exhibits longer cycle life with lower overpotential than polycrystalline LiMg at high current densities and areal capacities in symmetric cells. A critical current density (CCD) at the forefront of 2.5 mA cm−2 is achieved in Li3InCl6 (LIC) solid‐state system. The ASSLMB with high areal capacity (3.8 mAh cm−2), high current density (0.76 mA cm−2), and low negative/positive capacity N/P ratio (2.14) achieves exceptional cyclability over 160 cycles. The outcomes highlight a promising crystallographic regulation strategy toward practical applications of high‐performance lithium metal batteries.

Constructing high performance dry-processing oxide composite electrolyte via interfacial interactions for durable solid-state lithium batteries

Composite solid electrolytes (CSEs) have considerable combination properties, which have been considered as the most promising choice for realizing advanced solid-state lithium batteries. Yet the ionic conductivity of CSEs fails to meet the practical requirements. Herein, we develop a dry-processing CSEs based on Li1.5Al0.5Ge1.5(PO4)3 (LAGP) and succinonitrile (SN) through polytetrafluoroethylene fibrillation. On the one hand, SN can enable fast ion transport in ceramic network and serve as high-speed conducive path. On the other hand, the strong affinities of LAGP towards SN and anions can significantly improve the conductive behavior and restrict side reactions at electrolyte/Li interface. Under such regulations, the composite electrolyte exhibits high ionic conductivity (0.64 mS cm−1 at 30 °C), high transference number (0.50), and high oxidation potential (>5.0V vs. Li+/Li). The assembled lithium metal batteries demonstrate excellent stability over 300 cycles at 1.0C. This work demonstrates the ion migration mechanism and the interactions at the heterogeneous interface for SN enhanced CSEs, contributing to the development of durable solid lithium metal batteries with extended lifespan.

Synthesis, Structural Characterization, Optical Properties, and Biological Potency of Co(II), Cu(II), and Cd(II) Complexes With Heterocyclic Thiosemicarbazide Ligand: Insights From Molecular Docking Studies

ABSTRACTA novel heterocyclic thiosemicarbazide ligand, [(Z)‐N‐(2‐oxoindolin‐3‐ylidene)nicotinohydrazide] (H2L), and its Co(II), Cu(II), and Cd(II) metal chelates were synthesized and characterized using a variety of analytical methods, including elemental analysis, FT‐IR, UV–Visible spectroscopy, EI‐mass, fluorescence spectroscopy, X‐ray powder diffraction, and TGA. The structures and geometries of the complexes were determined using these methods as [Co2(H2L)2Cl2(H2O)4]·2H2O, [Cu(H2L)2Cl2(H2O)2]·2H2O, and [Cd(H2L)2Cl2(H2O)2], all having octahedral geometry. The particulate diameters for [Co2(H2L)2Cl2(H2O)4]·2H2O, [Cu(H2L)2Cl2(H2O)2]·2H2O, and [Cd(H2L)2Cl2(H2O)2] were 192.68, 68.48, and 192.74 nm, respectively using Debye–Scherrer equation and FWHM approach. The corresponding FWHM values were 0.0078, 0.0217, and 0.0075, whereas the crystal strain was calculated as (ε) = 0.0018, 0.0056, and 0.0054, and the dislocation density (δ) as 2.69 × 10−5, 2.13 × 10−4, 2.69 × 10−5 Å−2. Quantum chemical calculations for the ligand and its solid metal complexes were carried out utilizing DFT with the DMOL3 module. Furthermore, the optical sensing response of the free ligand H2L to Co(II), Cu(II), and Cd(II) ions was investigated, revealing that the presence of these metal ions enhanced the fluorescence spectra of the ligand. Additionally, the antibacterial effects of these compounds, as well as their cytotoxicity in human cancer cells, were investigated. Compared to its metal complexes, the ligand, H2L exhibits increased antibacterial activity against various bacteria. Tests on HepG‐2 and MCF‐7 cells were conducted to evaluate the compounds' anticancer efficacy against the standard, Doxorubicin. The ligand, H2L, demonstrated greater cytotoxicity against the HepG‐2 cell line than its metal complexes. Docking experiments were conducted to assess the interaction of the ligand and its complexes with HepG‐2 (PDB ID: 2OH4) and MCF‐7 (PDB ID: 3W2S) cells, using the XP glide technique and Schrödinger suite software.

A Novel Super-Toughness and Self-Healing Solid Polymer Electrolyte for Solid Sodium Metal Batteries.

Solid sodium metal batteries (SSMBs) offer an alternative promising power source for electrochemical energy storage due to their high energy density and high safety. However, the inherent sodium dendrite growth and poor mechanical properties of electrolytes seriously limit their application. Herein, a network structure composed of polyethylene oxide-based composite polymer electrolyte (CPE) is designed with liquid metal nanoparticles (LM) for SSMBs, in which LM can move in the solid electrolyte with the electric field driven. This effect can facilitate the inactivated sodium return to the metal sodium anode, and alloy with dendrites at the same time, which is beneficial for inhibiting the growth of dendrites. The symmetric cell with the CPE containing LM achieves good cyclic stability of more than 1800 and 800h at 0.1 and 0.2mAcm-2, respectively. The energy density of the pouch battery can reach 230Whkg-1. In sum, LM presents great potential to be employed as a performance reinforcement filler for CPEs, which paves the way for achieving high-performance SSMBs.

Inducing columnar-to-equiaxed transition by gradient impediment-flow optimization mechanism: The inheritance chain of solidification

Optimization of the metal solidification microstructure is a long-standing topic. It is the initial and critical guarantee of fabricating high performance metal materials, especially in the context of external field control, for example, for electromagnetic fields. However, tailoring the final solidification microstructure is extremely difficult because its mechanism is a long process inheritance chain which can be hardly observed by experiments. In this study, systematically simulations of the continuous casting using an electromagnetic swirling flow nozzle (EMSFN) was made to clarify this inheritance chain. It was newly found that a relatively uniform flow field inherited from a magnetic field generates a gradient impediment-flow optimization mechanism (GIFO), which is beneficial for both columnar-to-equiaxed transition (CET) and grain refinement. Specifically, 600 A increases the superheat dissipation, and the temperatures of the solidification front at 200 mm and 400 mm below the meniscus are increased by 15.47 K and 12.27 K, respectively, and the temperature gradient is decreased by 17.3 % and 22.8 %. The concentration gradient at the solidification front decreased by 89.9 %, 31.1 %, and 51.3 % at 200 mm, 400 mm, and 650 mm below the meniscus, respectively. Coupled changes in the temperature and concentration gradients impede dendritic growth and promote equiaxed grain nucleation. In addition, more equiaxed grain nuclei are transported to the forefront of the growing dendrite when the molten steel rotates and is transported from the inner to the outer regions. According to the simulation, the experimental validation proved that electromagnetic swirling flow nozzle was a convenient method for promoting this mechanism. It can optimize the solidification structure of Grade 70 carbon spring steel continuous casting billets with an increase of 21.26 % in the equiaxed grain ratio extremely low carbon segregation, and improved mechanical properties. This newly found mechanism can be considered as a generic theory for optimizing the solidification microstructure of alloys, which can guide the process design of various external field control technology.

Synthesis and Reactivity of an Alumanyl-Tin Species to Form an Al,N-Heteroallene Derivative.

The molecular chemistry of metal-metal bonds is crucial for understanding the bonding and reactivity of metal-containing molecules as well as solid metals and their alloys, especially with respect to their application as catalysts for organic transformations and industrial processes. Despite the high efficiency of the recently developed nucleophilic alumanyl anions in the synthesis of diverse Al-metal bonds, the bonding between main group metals in a low oxidation state and the Al atom remains largely unexplored. This paper describes the reaction of an alumanyl anion with a chlorostannylene precursor to afford a compound with an unprecedented covalent Al-Sn bond. The lability of the covalent Al-Sn bond renders it reactive toward the insertion of carbodiimide, N2O, and phenylacetylene. Remarkably, the reaction with benzonitrile furnished an unprecedented Al,N-heteroallene species that contains a linear Al═N═C linkage.

Nanofibers endow NASICON-type Na3.3La0.3Zr1.7Si2PO12 electrolyte/Na4MnCr(PO4)3 cathode excellent electrochemical properties

All-solid-state sodium-ion batteries (ASSSIBs) using composite polymer electrolytes (CPEs) are promising candidates for addressing the high cost, safety issues, and limited energy density of traditional lithium-ion batteries. The microstructure and morphology of active ceramic filler and cathode seriously affect the construction of ion/electron transport channels and electrochemical performance, while the contact tightness at the electrode/CPE interface determines the release of energy storage performance in ASSSIBs. Here, NASICON-type Na3.3La0.3Zr1.7Si2PO12 (NLZSP) ceramic nanofibers (NFs) and Na4MnCr(PO4)3@C (NMCP@C) NFs are prepared via electrospinning. NLZSP long NFs (L-NFs) can be uniformly dispersed in PVDF-HFP using ultrasonic treatment to create rapid ion transport pathways within the ceramic and polymer/ceramic interphases, enabling the CPE to achieve high ionic conductivity of 3.36 × 10−4 S·cm−1, wide electrochemical stability window (ESW) exceeding 5 V, low activation energy (Ea) of 0.28 eV and sodium-ion transference number (TNa+) of 0.65 at room temperature. Meanwhile, NMCP@C NFs can enhance electron conductivity and reduce the sodium ion migration path, and finally achieve a superhigh specific capacity (161 mAh·g−1) and energy density (534 Wh·kg−1) at 0.1C. Additionally, the integrated NMCP@C/CPE structure is incorporated into NMCP@C/CPE//Na solid state sodium metal batteries (SMBs), which exhibits excellent rate performance and high capacity retention of 78.8 % at 1C (1.4–4.3 V) and 70.5 % at 0.5C (1.4–4.6 V) after 200 cycles. This study offers valuable insights into constructing high-performance ASSSIBs.

Oil-based drilling cutting pyrolysis residues- phosphogypsum foamed ceramics: Basic properties, microsintering mechanism and heavy metals solidification

Oil-based drilling cutting pyrolysis residues(ODPR) and phosphogypsum(PG) are typical types of industrial solid waste in China, characterized by low utilization rate and high output. The large amount of untreated accumulation will release heavy metals(HMs) and other pollutants, posing risks to the environment. Therefore, there is an urgent need to develop a high value-added building material product that can reduce environmental hazards while improving utilization rate. Based on this background, this study uses ODPR and PG as raw materials to explore their potential applications in the field of foamed ceramics. Research has shown that different sintering processes have a significant impact on the appearance and performance of products. By adjusting the preparation process, foamed ceramic products with excellent performance can be prepared. When the sintering temperature is 925℃, the foaming agent dosage is 3 %, and the raw material ratio ODPR:PG:Borax=35:45:20, a foamed ceramic product with a porosity of 60.95 %, water absorption rate of 3.4 %, compressive strength of 4.8 MPa, thermal conductivity of 0.8016 W/(m·k), and acid and alkali resistance of 98.57 % and 99.44 % can be prepared. The product meets the relevant requirements of “Fired heat preservation brick and block (GB/T 26538)” and “ General Specification for porous ceramic products (GB/T 16533)”. The HMs content test showed that the Ni and Pb contents in the pre-sintered blanks were the highest, at 0.6308 mg/kg and 0.3182 mg/kg, respectively. However, after high-temperature calcination, the solidification rate of HMs could reach up to 98.93 %, and the leaching amount was significantly reduced. The three further evaluation methods indicate that HMs in the pre-sintered blanks and foamed ceramic products do not pose significant ecological risks. The research results provide a green inorganic insulation material in the field of solid waste control and building materials.

Recent progress in the development of liquid metal plasma facing components for magnetic fusion devices

One of the most critical challenges for future fusion reactors is to develop longevity plasma-facing components (PFCs) exposed to extremely high heat and neutron loads. As opposed to those employing solid metals, PFCs with flowing liquid metals (LM) have shown self-healing, heat removal and good impurity control capabilities, all essential to fusion devices. Recently, significant progress in LM-PFC development has been reported globally, with data from several magnetic fusion devices. These studies reveal that LM-PFCs can endure extreme heat fluxes while maintaining plasma compatibility. New design concepts have been proposed and numerically analyzed, advancing models for liquid PFCs in future reactors. Despite existing technical challenges, these developments suggest that LM-PFCs hold promise for future fusion applications.

Synthesis, characterization and biological studies of transition metal complexes of dehydroacetic acid Schiff bases derived from 3-aminomethyl pyridine

The solid metal complexes of Cu (II), Ni (II), Fe (III), Co (II), Mn (II) and Cd (II) with DHA Schiff base ligand derived from DHA and aromatic primary amine 3-aminomethyl pyridine were synthesized and characterized by elemental analysis, spectroscopic techniques (FTIR, UV-VIS, 1HNMR and XRD), magnetic susceptibility measurement, thermogravimetric analysis and differential thermal analysis (TGA/DTA) and investigated for biological activities like anti-bacterial, ant-fungal, antioxidant and anticancer activity. The structure of synthesized DHA Schiff base ligand and all metal complexes were confirmed by spectroscopic methods, stability of complexes was studied by TGA/DTA. DHA Schiff base ligand and all metal complexes were found to be biologically active.

Modifying x-ray streak cameras for operation on igniting fusion experiments.

The National Ignition Facility produced the first nuclear fusion experiment demonstrating net positive energy gain on December 5, 2022. The x-ray streak camera that measures the bang time and burn-width from this landmark experiment had an electronic failure and did not record data. The CCD sensor was replaced with a radiation hardened CMOS sensor that has since demonstrated successful operation on repeat ignition shots. Concurrently, an instrument artifact was identified that occurs when the signal consists primarily of energetic x rays >15keV (common on burning plasma experiments). This artifact, which appears as a background pedestal, arises from the x-ray back-fluorescence generated by the solid metal accelerating mesh behind the photocathode in the streak tube. We have mitigated this background signal by limiting the sensitive area of the photocathode. Herein, the details of the modifications and the results are presented.

Numerical investigation of arc characteristics and metal properties in ELAMF-assisted WAAM with wire retraction

In this study, a multi-physics integrated model of wire arc additive manufacturing (WAAM) with wire retraction and external longitudinal alternating magnetic field (ELAMF) assistance is proposed and validated, and the effect of ELAMF on the arc plasma characteristics and metal properties are systematically and quantitatively investigated. The model comprehensively takes the arc plasma heating, wire dynamic retraction, droplet transfer, the formation and diffusion of metal vapor, the melting and solidification of molten metal, and the stirring effect of ELAMF into account. The simulated results show that ELAMF has compressed the arc morphology, and decreased the temperature, potential, current density and static pressure, which are most pronounced when the wire is at an elevated position and the transient current is at its peak phase. Meanwhile, the formation of low-temperature and low-velocity cavities in the center of arc column are promoted by ELAMF, consequently diminishing the energy transferred from the arc plasma to molten pool through thermal conduction and mitigating the squeezing of the arc plasma on the surface of molten pool. The results also demonstrate that the ELAMF has reduced the temperature gradient of liquid metal inside the molten pool, and intensified the forced convection for the occurrence of multiple circulations.

Fabrication of customized open-cell titanium foams by direct foaming for biomedical applications

Titanium (Ti) foams offer a promising alternative for bone reconstruction and repair due to their high porosity and lower stiffness compared to solid metals, which improves in vivo osseointegration by reducing the stress shielding effect and allowing bone ingrowth. In this work, customized Ti foams were successfully fabricated for the first time at room temperature using a direct foaming method. Ti powder suspension with a water-soluble surfactant and environmentally friendly thickener was foamed by mechanical stirring. Then, 3D-printed moulds were utilized to achieve near-net shape foams, which were subsequently consolidated by sintering, thus avoiding the need for complex processing of molten Ti. The resulting Ti foams exhibited a cancellous-like open-cell structure, high porosity (> 80%), and a five times higher effective surface area than a 3D Ti mesh with a primitive cubic-based cell fabricated by additive manufacturing. In addition, the Ti foams exhibited similar mechanical properties to cancellous bone and facilitated the adhesion, proliferation, and maturation of human osteoblasts in vitro.

Predicting Reactivity and Passivation of Solid-State Battery Interfaces.

In this work, we build a computationally inexpensive, data-driven model that utilizes atomistic structure information to predict the reactivity of interfaces between any candidate solid-state electrolyte material and a Li metal anode. This model is trained on data from ab initio molecular dynamics (AIMD) simulations of the time evolution of the solid electrolyte-Li metal interfaces for 67 different materials. Predicting the reactivity of solid-state interfaces with ab initio techniques remains an elusive challenge in materials discovery and informatics, and previous work on predicting interfacial compatibility of solid-state Li-ion electrolytes and Li metal anodes has focused mainly on thermodynamic convex hull calculations. Our framework involves training machine learning models on AIMD data, thereby capturing information on both kinetics and thermodynamics, and then leveraging these models to predict the reactivity of thousands of new candidates in the span of seconds, avoiding the need for additional weeks-long AIMD simulations. We identify over 300 new chemically stable and over 780 passivating solid electrolytes that are predicted to be thermodynamically unfavored. Our results indicate many potential solid-state electrolyte candidates have been incorrectly labeled unstable via purely thermodynamic approaches using density functional theory (DFT) energetics, and that the pool of promising, Li-stable solid-state electrolyte materials may be much larger than previously thought from screening efforts. To showcase the value of our approach, we highlight two borate materials that were identified by our model and confirmed by further AIMD calculations to likely be highly conductive and chemically stable with Li: LiB13C2 and LiB12PC.

Phase evolution and heavy metal solidification of cement desulphurized electrolytic manganese residue composite cementitious system under steam curing conditions based on thermodynamic simulation

The mechanical properties and microstructure of desulphurized electrolytic manganese (D-EMR) cement mortar under steam curing at 80 °C for 7 h and 7 days and standard curing for 3 days and 28 days were studied. The hydration products, microstructure and pore distribution were studied by Quantitative X-ray diffraction analysis (QXRD), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), thermogravimetric-differential thermal analysis (TG-DTA) and backscattered electron (BSE). At the same time, the evolution of hydration products with age and the existence form of heavy metals under different curing conditions were simulated by GEMS thermodynamics. The results show that steam curing can promote the hydration reaction of cement and the secondary hydration of D-EMR. With the extension of steam curing time, the mechanical properties of the early stage are significantly improved. At a D-EMR content of 15 %, the compressive strength of D-EMR cement mortar after steam curing for 7 days is 1.15 times that of the control group under the same conditions, and the content of calcium hydroxide (CH) is 65.91 % of the control group. Steam curing can significantly improve the degree of C3S hydration of cement clinker and the secondary hydration of D-EMR, and increase the degree of polymerization of hydrated calcium silicate (C-S-H) gel. In addition, thermodynamic simulation showed that when the pH value was greater than 7.5, Mn2+ was mainly stable in the form of Mn(OH)2, MnOOH and Mn3O4, and there was no leaching risk. This will provide theoretical support for the use of D-EMR as a new type of supplementary cementitious material (SCM).

Optimizing hot tearing susceptibility of Al-5.5Zn-2.4 Mg-1.3Cu alloys by grain refinement, increasing mold and casting temperature

The Al-Zn-Mg-Cu alloy is widely used in automotive lightweighting and other applications due to its excellent mechanical properties. However, when this alloy is cast using metal molds, it exhibits high hot tearing susceptibility (HTS), increasing the risk of use. Volumetric shrinkage due to density differences during the transition from liquid to solid metal produces shrinkage stresses. At the same time, lacks feeding of the remaining liquid phase in the late solidification stage can also lead to hot tearing. The purpose of this paper is to present a device for quantitatively determining and optimizing HTS. The relationship between solidification shrinkage displacement and stress was tested in a quantitative way using a Self-designed T-tester equipped with stress and displacement sensors. The test results show that the reduction of grain size shifts the solidification shrinkage of the alloy and reduces the solidification shrinkage stress, which avoids hot tearing caused by higher solidification shrinkage stress and local stress inhomogeneity. Secondly, the grain size reduction increases the number of feeding channels in the solidification vulnerable stage, and more liquid phase is available for crack healing. In addition, the influence of casting process parameters on the HTS was studied.

Adsorption behavior and solidification mechanism of Pb(II) on synthetic C-S-H gel with low and high Ca/Si ratios in highly alkaline environments

Adsorption behavior is rarely investigated as a heavy metal solidification mechanism in alkali-activated municipal solid waste incineration (MSWI) fly ash compacts. This study simulates the adsorption behavior and solidification mechanism of Pb(II) on synthetic C-S-H gel with low and high Ca/Si ratios in high alkaline internal pore solution environments of alkali-activated MSWI fly ash compacts. The study examines the fraction of Pb(OH)3- in a Pb(II) solution (100 mg/L) at pH 11.8 and 12.4, with percentages of 85.9–90.6 % and 93.4–95.1 %, respectively. pH values are identified as the key parameter affecting the adsorption capacity of C-S-H for Pb(II). The equilibrium adsorption capacities (Qe) values of Pb(OH)3- (pH = 11.8) for C-S-H with Ca/Si ratios 1.20 and 0.60 are approximately 104 mg/g and 110 mg/g. At pH 12.4, the C-S-H gel with a Ca/Si ratio = 1.20 performs better in terms of adsorption. The adsorption of Pb(OH)3- by C-S-H is predominantly a chemisorption process at pH 11.8. Based on the ΔG0 data, the adsorption process is determined to be spontaneous. The 1.16 eV LUMO and HOMO difference for Si2O(OH)6 + Pb(OH)3-, compared with the 3.92 eV difference for Si3O2(OH)8 + Pb(OH)3-, indicates a lower difficulty of electron transition in the reaction between Si2O(OH)6 and Pb(OH)3-. XPS and FTIR results confirm the dehydration and combination of Pb(OH)3- and Si-OH in a silicate tetrahedron (Q1 or Q2) on the C-S-H surface to create Si-O-Pb. Partial Ca(II) in C-S-H gel can be replaced or released during the Pb(II) adsorption process. These findings hold significant theoretical importance for the adsorption and solidification mechanism of Pb(II) in alkali-activated MSWI fly ash specimens.