Journal of Adhesion Science and Technology

Li, Chang; Sun, Han; Han, Xing; Ge, Weiwei; Sun, Yichang

2025 Journal of Adhesion Science and Technology

doi: 10.1080/01694243.2025.2450267

Abstract Nickel-based Tungsten Carbide (WC) materials have excellent wear resistance and high temperature stability. They are prone to cracking during laser cladding due to the rapid cooling and heating characteristics. The sensitivity of cracking differs when cladding different substrates, which is a bottleneck for the industry. Quantitatively revealing the laser cladding mechanism of nickel-based WC is significant for optimizing the process. In this paper, a coupling model of the thermal field, flow field, and stress field was established for the laser cladding of nickel-based WC60 on a 42CrMo substrate. The model considered the influence of the powder absorption, surface tension and buoyancy on the flow for liquid metal and focused on analyzing the transient evolution during laser cladding. Cladding samples were prepared and subjected to the X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive Spectroscopy (EDS), and microhardness characterization experiments. The morphology and mechanical properties of WC60 based on nickel were observed, and its solidification characteristics were analyzed. The calculations show that the maximum temperature during laser cladding reaches 2529 K, forming an upward Marangoni flow with a maximum velocity of 0.25 m/s. The thermal stress of the cladding layer reaches 616 MPa, and the residual stress reaches 647 MPa. The experiments show that WC particles are spherical and exist in the cladding layer as hard phases, deposited in the middle and lower parts of the cladding layer, which effectively enhances the hardness of cladding layer. WC particles impede columnar crystal growth, and some WC particle boundaries undergo melting, leading to the diffusion of tungsten elements into the cladding layer. This study provides a theoretical basis for optimizing the laser cladding process of nickel-based WC and improving the coating performance.

Ghorbel, Rami; Ktari, Ahmed; Abid, Dorra; Ben Abdallah, Rahma; Haddar, Nader

2025 Journal of Adhesion Science and Technology

doi: 10.1080/01694243.2025.2450277

Abstract In this study, the influence of repeated thermal cycling during multi-pass welding on the microstructural transformations and mechanical properties of austenitic stainless clad-steel plates (ASCSPs) was investigated, with a particular focus on the clad layer. A novel methodology was employed, involving the complete filling of the groove length and gradually shortening subsequent passes. Microstructural characterization of various zones within the welded joint was conducted using optical microscopy. The results demonstrated that repeated thermal cycles during multi-pass welding caused significant microstructural changes in the weld metal clad layer (WM-CL), including the transformation from columnar to equiaxed grains and the evolution of δ-ferrite morphology from dendritic to skeletal. Additionally, the ferrite number decreased from 8.5 ± 2 in the sixth pass to 2 ± 0.5 in the ninth pass, correlating with increased heat input (HI) from 15.5 kJ/cm to 25.8 kJ/cm and repeated thermal cycling. Furthermore, the heat-affected zone (HAZ) exhibited coarse-grained polygonal austenite near the fusion line, with recrystallization attributed to the high thermal input. Micro-hardness measurements showed a reduction from 320 HV in the sixth pass to 195 HV in the ninth pass, linked to alloying element diffusion and ferrite content reduction. The findings highlight the importance of controlling thermal cycles and HI during multi-pass welding to optimize the microstructural stability and mechanical properties of ASCSP welded joints. These results provide valuable insights for improving the performance of ASCSP in industrial applications.

Nodeh, Marzieh; Maslouhi, Ahmed; Desrochers, Alain

2025 Journal of Adhesion Science and Technology

doi: 10.1080/01694243.2025.2450049

Abstract This study presents a new method for predicting the fatigue life of aluminum adhesive-bonded joints. The approach involves experimental tests to establish fatigue failure criteria using acoustic emission monitoring to detect damage onset, along with a finite element (FE) model to analyse changes in energy release rate at the embedded crack tip. The proposed method comprises three key steps. In the initial stage, a 3D failure surface criterion is experimentally generated, connecting the maximum total energy release rate (GT) and the mixed mode ratio (GII/GT) to the number of cycles (N) required for initiating the crack propagation. In the second step, the total energy release rate (GT) and the corresponding mixed mode ratio (GII/GT) at the crack tip of a single lap joint under different external loads are numerically determined utilizing the virtual crack closure technique. Mathematical equations linking the applied load (P) to the associated values of GTmax and GII/GT are established. Ultimately, once the energy release rate and mixed mode ratio for a given load are determined, the number of cycles required for initiation of crack growth can be extracted from the experimentally derived failure surface in the initial step. The predictive model shows excellent correlation with experimental data, depending solely on the adhesive system rather than joint design.

Cooper, Marcus; Minnard, Alexandra; Taneng, Evita; Raghavan, Dharmaraj

2025 Journal of Adhesion Science and Technology

doi: 10.1080/01694243.2024.2444315

Abstract The primary objective of this study was to investigate the role of processing methods on the dispersion of unfunctionalized Laponite in latex and the property enhancements of nanocomposite. Processing methods used to disperse Laponite included planetary shear mixing (PSM), ultrasonication, and hand-mixing. Two complimentary characterization techniques were used to evaluate the dispersion of the Laponite in nanocomposite samples: Confocal laser scanning microscopy and transmission electron microscopy (TEM). Nanocomposites processed using PSM showed the least agglomeration of Laponite, followed by hand mixing and ultrasonication. Cryo TEM of latex showed a honeycomb structure with the center of honeycomb occupied by the latex particles, while the nanocomposite showed Laponite nanoparticles surrounding the exterior of the latex particle. Hygrostability studies showed that the average saturated moisture adsorbed by the nanocomposite is strongly dependent on the sample thickness, laponite loading and the processing condition adopted in mixing Laponite with the latex Among all the processed nanocomposites, the thermo-mechanical performance of PSM processed nanocomposite showed the least decrease in modulus compared to latex. These results can have a strong bearing on the design of next generation adhesives.

Zhang, Qiyu; Tang, Yali; Lu, Lixin; Qiu, Xiaolin; Pan, Liao

2025 Journal of Adhesion Science and Technology

doi: 10.1080/01694243.2024.2449405

Abstract The wood adhesive industry’s reliance on traditional petroleum-based adhesives poses environmental and health risks, necessitating the development of sustainable, bio-based alternatives. To develop a modified sucrose-based adhesive with good water resistance, the hydrolysis products of sucrose were crosslinked with polyethyleneimine (PEI) through the Maillard reaction to form a dense crosslinked network. Fourier Transform Infrared Spectroscopy (FTIR) confirmed the interaction between the sucrose derivatives and PEI. Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) revealed the thermal curing behavior and thermal stability of the modified sucrose-based adhesive. Additionally, the optimal preparation conditions for the modified sucrose-based adhesive were investigated. Compared to unmodified natural sucrose-based adhesives, the wet shear strength and dry shear strength of the modified sucrose-based adhesive were increased by 212% and 279%, both exceeding the Chinese national standard GB/T 9846-2015 (0.7 MPa). This process is simple and cost-effective, producing a formaldehyde-free, water-resistant sucrose-based adhesive that offers a sustainable solution for wood adhesives with significant application potential.

Senthamizh Selvan, S.; I. S., Rajay Vedaraj

2025 Journal of Adhesion Science and Technology

doi: 10.1080/01694243.2024.2449408

Abstract This study examines the influence of sodium hydroxide treatment on the tensile and flexural properties of carbon/ramie/epoxy hybrid composites, validated through artificial neural network modeling. Among untreated, 1 wt.%, and 5 wt.% sodium hydroxide-treated samples, the 3 wt.% treatment showed the highest improvements, achieving a tensile strength of 524 MPa and a flexural strength of 697 MPa, with respective increases of 27.48% and 43.75%. 1 wt.%, 3 wt.%, and 5 wt.% of sodium hydroxide degraded the ramie fibers, causing weight losses of 4.6%, 8.5%, and 18.5%, respectively. Fourier transform infrared spectroscopy confirmed the removal of surface impurities such as wax, hemicellulose, and lignin, enhancing the bonding between the fibers and the matrix, while field emission scanning electron microscopy revealed improved structural integrity. The superior properties of the 3 wt.% sodium hydroxide-treated composite were attributed to a stronger interface between the fibers and the matrix. Additionally, the artificial neural network model accurately predicted the tensile and flexural strengths using time, load, and extension as inputs, with regression coefficients of 0.99998 and 0.99982 and a minimal error of 3.29%. These results highlight the optimal performance of 3 wt.% sodium hydroxide-treated composites as sustainable materials for structural applications in the automotive, aerospace, and construction sectors.