Magnesium (Mg) alloys are attractive lightweight structural materials for transportation, aerospace, electronics, and energy-efficient engineering because of their low density, high specific strength, castability, and damping capacity. However, their broader use remains constrained by limited wear and corrosion resistance, modest elevated-temperature performance, and the high environmental burden of primary Mg production. Simultaneously, large quantities of industrial, agricultural, food-derived, and consumer wastes continue to accumulate worldwide, creating a strong incentive to convert these residues into functional materials inputs. In this context, waste-reinforced Mg matrix composites have emerged as a promising class of circular lightweight materials. This review critically evaluates uniform and functionally graded Mg composites produced from waste-derived reinforcements and recycled Mg feedstocks. It examines magnesium production, recycling, and waste-generation trends; analyzes major reinforcements such as fly ash, red mud, eggshell, squid quill ash, and waste glass; and assesses the main liquid-state and solid-state processing routes used to incorporate these materials. The review also synthesizes their effects on microstructure, mechanical behavior, wear, corrosion, damping, thermal response, and strengthening mechanisms. Particular attention is given to chip-based graded Mg composites as an advanced form of dual valorization. Overall, this review provides a basis for future development, analysis, and application of sustainable Mg composites.

The high temperature flow behavior of TA15 alloy at different deformation temperatures and strain rates has been reported and predicted by the traditional phenomenological constitutive and temporal deep learning models in this research. Increasing temperature and decreasing strain rate lead to the decrease in ultimate tensile strength (UTS) and increase in elongation. The minimum UTS and maximum elongation are 49.28 ± 2.13 MPa and 458.09 ± 8.62

This study investigates the influence of pulse frequency on the microstructure and mechanical properties of 321 stainless steel micro plasma arc welding (MPAW) joints. The experiment selected three pulse modes: direct current (DC), 5 Hz, and 500 Hz. The average grain size of the fusion zone (FZ) decreased from 7.1 mu m at DC to 6.7 mu m at 5 Hz and 5.8 mu m at 500 Hz. For heat affected zone (HAZ),the size decreased from 7.1 mu m to 6.6 mu m and 6.3 mu m. All tensile specimens fractured in the base material (BM), therefore no significant changes in strength were observed. Their tensile strength is higher than that of the BM, while the elongation has decreased. Grain refinement leads to a notable increase in microhardness, with the hardness value at the weld center reaching 190 HV at 500 Hz, compared to 180 HV for DC and 5 Hz welds.

TA15 titanium alloy is widely used in load-bearing components and protective parts of aero-engines because of its high tensile strength, hardness and fatigue resistance, as well as high fracture toughness and ductility. In this paper, the hot compression experiment of TA15 alloy was carried out by means of Gleeble−3500 thermal simulator. The flow stress behavior of the alloy was characterized by the phenomenological constitutive model and the physical basic constitutive model, respectively, and both constitutive models considered the influence of strain. According to the energy dissipation coefficient and instability parameters, the 3D processing maps of Murty criterion were constructed. The results show that the average relative errors of the phenomenological and physical constitutive models are 7.8

This research investigates hot deformation and stress relaxation behavior of TB8 alloy by hot tensile tests from 650 to 725 °C and 0.1 to 0.001 s−1and hot stress relaxation test from 650 to 725 °C and 50 to 150 MPa. The strain compensation Arrhenius constitutive and TCN models are established to describe the flow behavior with various deformation conditions. Stress relaxation and creep behavior are fitted by equations. The range of tensile strength and elongation are 78.12 to 309.46 MPa and 38.56 to 186.61

Abstract Following hot forming, TC2 titanium was subjected to heat treatment at temperatures between 900 °C and 990 °C for 0.5 to 2 hours. It was observed that, with a constant holding time, increasing temperature resulted in a minor decrease in the volume of the primary α phase. Meanwhile, primary α phase and regions near grain boundaries merged and coarsened, resulting in a slight increase in grain size from 15.86 μm (900 °C) to 17.77 μm (930 °C). Furthermore, extending the holding time also caused the grain size of the primary α phase to increase. Based on these findings, a modified Sellars model was established, which exhibited high accuracy.

Diffusion bonding (DB) of aluminum alloys faces significant technical challenges, requiring thorough surface preparation and precise control of process parameters. To enhance the joint quality of 7B04 aluminum alloy sheets, pure aluminum (Al) and 7075 aluminum alloy powders were used as interlayers. In the DB experiments, nano-sized Al powder and micro-sized 7075 powders with different particle sizes served as interlayer materials. Compared to DB without an interlayer, using powder interlayers substantially reduced the bonding temperature while improving overall joint performance, with deformation kept below 6%. The lap shear strength (LSS) of the bonded 7B04 joints was significantly higher when 45 μm and 75 μm 7075 powders were used, compared to the 5 μm 7075 powder. The joint with a 50 nm Al powder interlayer achieved a maximum LSS of up to 220 MPa and exhibited considerably higher microhardness. Additionally, the mixed Al/7075 powder interlayer effectively decreased voids at the joint interface, contributing to increased LSS.

The dynamic recrystallization (DRX) behavior of TC31 titanium (Ti) alloy was studied at 840–960 °C and 0.0001–0.1 s−1. The results showed that the volume fraction of recrystallized grain increased and the dislocation density gradually decreased with the strain increasing. The influence of strain rate on the critical dislocation density of DRX was greater than that of temperature, the strain rate was 0.001 s−1 at 920 °C, and the critical dislocation density was 3.3 × 1014 m−2. The DRX behavior was carried out in a smaller strain rate range through a dynamic softening map, and the deformation temperature range was in a similar pattern with normal distribution. The volume fraction of DRX could be validly predicted by the JMAK model, the value of R was 0.995, and the value of the root mean-squared error (RMSE) was 2.96

The present research investigates the hot deformation behavior of the diffusion bonded Ti-6Al-4V alloy. High temperature tensile experiments were carried out at various pre-strain condition with the temperature of 850 degrees C and the strain rate of 10-3 s- 1. The microstructure evolution was analyzed through the EBSD method. The true stress-strain curves were utilized to develop the deep learning (DL) model for the material. Three Transformer based models were designed to predict the flow behavior. The Long Short-Term Memory (LSTM) and Adaptive Sparse Self-Attention (ASSA) modules were used to imposed to the Transformer model to further enhance its performance. As the increasing of the pre-strain, the strength and elongation increased and then decreased. The pre-strain process promoted the DRX process and refine the grain size. The R values of training and test dataset achieved 0.9995 and 0.9994 by the developed LSTM-ASSA-Transformer model, as well as the low RMSE, MAE and AARE values, suggesting its high performance to predict the flow behavior of the diffusion bonded Ti-6Al-4V alloy.

To investigate the microstructure evolution and instability during hot deformation, the hot compression experiment was conducted at deformation conditions of 700, 740, 780, 820℃ and strain rates of 0.001, 0.01, 0.1, 1s−1. The modified Johson–Cook constitutive model and 3D hot processing map were established based on experimental data. The finite element simulation was modified based on J–C model and the secondary development based on the 3D instability maps was utilized to investigate the instability region during hot compression experiment. The metrics of R and AARE of constitutive model were 0.9991 and 0.8

Wire arc additive manufacturing (WAAM) parts have typical lamellar structure characteristics, but its evolution law in the process of compression deformation is not clear. In this paper, rare earth magnesium alloy straight wall parts were prepared by gas tungsten arc welding (GTAW). Due to interlayer remelting, the microstructure is alternately coarse-grained layer (innerlayer region) and fine-grained layer (interlayer region) in the building direction, and the grain sizes are 13.4 mu m and 10.5 mu m, respectively. In the process of compression deformation, the innerlayer and interlayer regions are thinning, but the uneven deformation of each layer is caused by the difference of grain size. With the increase of deformation, the coordinated deformation of coarse-grained layer and fine-grained layer alleviates the difference of layer thickness. The deformation is dominated by intragranular slip, and the increase of dislocation density improves the mechanical properties of the material. The average microhardness increases from 88.2 HV0.1 to 100.5 HV0.1. Compression deformation inhibits the grain growth in the central region to a certain extent. The grain shape gradually changes from equiaxed to spindle, and the eutectic phase at the grain boundary flows with the grain deformation.

This study conducted high-temperature tensile tests at temperatures from 700 degrees C to 850 degrees C and strain rates of 0.0001 s-1 to 0.1 s-1 to investigate the high-temperature deformation behavior and microstructure evolution. A traditional constitutive model and five time series deep learning (DL) models were employed to analyze the high-temperature behavior. The elongations at 850 degrees C for strain rates from 0.1 s-1 to 0.0001 s-1 were 81.34 %, 149.20 %, 198.12 %, and 374.93 %, respectively. The increase in true strain and temperature, accompanied by the reduction of strain rate, could promote dynamic recrystallization (DRX). Nevertheless, excessive deformation time could lead to grain growth. The R2 value for the strain-optimized Arrhenius constitutive model was 0.9806, however, it cannot accurately predict the high-temperature deformation behavior at low strain rates (0.001 s-1 and 0.0001 s-1) or high temperatures (800 degrees C and 850 degrees C). The LSTM-Transformer model had the best performance, attaining the R2 value of 0.9994, as the combination of LSTM and Transformer enabled the model to effectively capture both local temporal patterns and global information. No overfitting was observed in five models. A window size that was too small leaded to overfitting and fluctuations in the prediction data, while a window size that was too large also resulted in overfitting and required significant computational resources. The optimal prediction accuracy was achieved with a window size of 200. This work presents an effective approach for the intelligent high-temperature forming of titanium alloys.

A unified viscoplastic constitutive model was established to predict the microstructure and damage evolution of diffusion bonded (DB) titanium alloy during the hot twist-bend forming based on the results of elevated temperature uniaxial tensile experiments. The influence of physical internal variables were considered by the viscoplastic model, which uses a genetic algorithm to optimize the parameters. Then, Abaqus and its subroutine Vumat were used to simulate the evolution of grain size, dynamic recrystallization (DRX) fraction, and damage evolution of titanium alloy hollow fan blades during hot stamping. By comparing the simulation results with the experimental results, the application of the unified viscoplastic model is proved to be reliable. Finally, the fan blade body manufactured by twist-bend forming under the process of Part-800-10-6 is smooth, without surface defects, and forming quality is better. The research results can provide guidance for the mass manufacturing of TC4 titanium alloy wide-chord hollow fan blades.

This research aims to characterize the effects of elevated temperature and stress state on the yield and fracture behavior of forged TC4 alloy. The uniaxial tensile, compression, and shear experiments were performed with different geometry under wide stress triaxiality at 760-800 degrees C. The experimental results indicate that the strength of TC4 titanium alloy decreases monotonously and unevenly with the temperature increase. The tension-compression asymmetry changes nonlinearly with temperature and strain, and this asymmetry decreases with increasing temperature. With the increase of stress triaxiality, the dimples in the fracture morphology become larger and deeper, and the ductile fracture mechanism changes from shear fracture to dimple fracture mechanism. A modified-JC constitutive model was proposed, and the coefficient of determination are about 0.981 and 0.971 for UTS and UCS. The temperature related yield function of Cazacu-Barlat2004 was constructed to describe the non-uniform evolution characteristics related to temperature and strain, and the fracture-related variables were calibrated with the hybrid experimental and numerical method under acceptable prediction accuracy. Finally, the temperature-related variables were successfully introduced into the DF2016 fracture model, and the fracture occurrence under different temperature and stress states were predicted with small prediction error. These research results can provide a basis for the shape and performance control of titanium alloy in the hot forming process.

An efficient thermal conduction characteristic is significant for electronic packaging materials. The diamond-copper (Cu) composite material is considered to offer the most potential as a thermal management material, however, the coefficient of thermal conductivity (CTC) of the material is decreased due to the presence of bonded interface defects and the poor wettability, limiting the application of the material. Spark plasma sintering (SPS) diffusion bonding was used to join the diamond-Cu composite material. After adding a molybdenum (Mo) interlayer to the bonded interface, a reliable bonded interface was formed. The CTC of the material increases from 658.1 W/(m center dot K) to 724.33 W/(m center dot K), and the coefficient of thermal expansion (CTE) is 6.1 x 10-6 K-1, which matches well with the semiconductor chip. The reduction of interfacial defects, the enhancement of bonding ability, the elevation of material densities enhance the thermal conductivity of the material, the generation of Mo2C at the interface enhances the coupling of phonons at the interface, the hybridization of electron orbitals, and thus the enhancement of interfacial thermal conductivity. The research provides theoretical support for modification of the interface of the diamond-Cu composite material.

The diffusion‐bonded interface of diamond/Cu composites, with or without a Ni foil interlayer, is fabricated using the spark plasma sintering (SPS) diffusion bonding process. The shear strength and thermal conductivity of the diffusion‐bonded interface are tested, and their microstructure, element distribution, and fracture morphology are analyzed using an optical microscope, scanning electron microscope, energy‐dispersive spectrometer, and X‐ray diffractometer. The results show that the shear strength and thermal conductivity of the diffusion‐bonded interface of the diamond/Cu composite with the Ni foil interlayer increase by 23.29% and 58.98%, from 45.12 MPa and 347.73 W (m K) −1 to 55.63 MPa and 552.83 W (m K) −1 , respectively, compared to the interface without the Ni foil interlayer. The presence of the Ni foil interlayer significantly reduces the voids and holes at the diffusion‐bonded interface, with Ni diffusing to both sides of the interface. This diffusion leads to the formation of an α single‐phase CuNi solid solution with Cu and the production of the Ni 3 C phase with C. At the SPS diffusion‐bonded interface with the Ni foil interlayer, the extensive solubility of Ni in Cu and the formation of carbides greatly contribute to the improvement of thermal conduction across the interface.

The high-strength aluminum alloy 7B04 used in aircraft structures poses challenges in welding. In this study, 7075 aluminum alloy powder is used as an interlayer to strengthen the vacuum diffusion bonding (DB) joint of 7B04 aluminum alloy. Surface treatments with plasma activation before DB can effectively increase the bonding rate and lap shear strength (LSS) of the joint. The effects of DB temperature, pressure, and holding time on the joint LSS were analyzed by developing a quadratic regression model based on the response surface method (RSM). The model’s determination coefficient reached 99.52%, with a relative error of about 5%, making it suitable for 7B04 aluminum alloy DB process parameters optimization and joint performance prediction. Two sets of process parameters (505 °C-5.7 h-4.5 MPa and 515 °C-7.5 h-4.4 MPa) were acquired using the satisfaction function optimization method. Experimental results confirmed that the error between measured and predicted LSS is approximately 5%, and a higher LSS of 174 MPa was achieved at 515 °C-7.5 h-4.4 MPa.

The microstructure, mechanical performances, and wettability of Sn58Bi solder modified by different contents of Ag nanoparticles were investigated. Analysis revealed that the microstructure of Sn58Bi/Cu solder joint underwent refinement upon adding Ag nanoparticles. In addition, the growth of interfacial intermetallic compound (IMC) layer exhibited efficient suppression. With adding 1.0 wt

Forming limit diagram (FLD) is a crucial tool for assessing the formability of sheet metals under various forming conditions. However, conducting FLD experiments can be challenging and timeconsuming requiring numerical determination of FLDs. Marciniak-Kuczy & nacute;ski (M-K) theory is one of the most well-known instability criteria for calculating forming limits, and the rapid development of crystal plasticity models provides a feasible framework for better understanding the relation between flow localization and material microstructure. Therefore, integrating the M-K theory with advanced crystal plasticity models offers a potential approach to precisely predict forming limits and explore the complex interaction be tween material behavior and microstructural characteristics. In this study, a crystal plasticity finite element (CPFE) model considering damage evolution was developed based on the microstructure and crystal orientation of a TA32 titanium alloy sheet. The material parameters for the proposed model were calibrated through uniaxial tensile tests and microstructure characterization. The internal correlation between damage evolution and the dislocation slip mechanism under different strain paths was analyzed at the grain scale. Additionally, the FLD of the TA32 sheet at 750 oC was predicted by coupling the CPFE model with the M-K theory. The results show that the proposed CPFE model accurately predicts the macroscopic mechanical response, microscopic inhomogeneous deformation, and damage evolution behavior of the TA32 sheet under different strain rates at 750 oC. The difference in the deformation behavior and damage propagation was mainly attributed to the anisotropic activation of various slip systems. The basal and prismatic slip systems of the basal bimodal texture in the original sheet were difficult to be activated under different strain paths, making it easier to induce damage than the transverse texture. The FLD predicted by the CPFE-M-K coupling model agrees well with the Nakazima test results, accurately capturing the decrease in the limit of major strain near the equibiaxial tensile region. This decrease is closely related to the anisotropy of the mechanical properties of the material. Furthermore, the change in the initial inclination angle of the groove in the CPFE-M-K coupling model considerably affects the prediction accuracy of the forming limits of the TA32 sheet. The critical initial inclination angles within the strain increment ratio ranges of-0.5-0.5 and 0.6-1.0 are 0 degrees and 90 degrees, respectively.

In recent years, the demand for magnesium alloys has led to a rise in magnesium scrap production. Eggshells (ES) have emerged as a cost-effective reinforcement for magnesium composites. This study repurposes AZ91 magnesium chips by combining them with ES particles to create functionally graded composites with enhanced properties. The process involves collecting, cleaning, pre-mixing, melting, and blending the materials using stir casting. A gradient composite is formed through centrifugal casting, effectively dispersing ES particles to prevent agglomeration. The composite exhibits significant improvements in hardness, tensile, and compressive strength in the outer zone, with enhancements of approximately 34