Material compatibility remains a critical challenge for high-temperature liquid-metal coolant systems. While corrosion in liquid tin (Sn) has been extensively investigated, the temperature-dependent degradation of structural Ni-based alloys and the associated dealloying mechanisms have not been systematically clarified. Here, the compatibility of Inconel 625 with liquid Sn was evaluated via static immersion tests under vacuum at 650, 850, and 1050 degrees C. The results reveal that degradation is governed by a selective dealloying process, involving simultaneous attack on grain interiors and interfacial defects, including grain boundaries (GBs) and annealing twin boundaries (ATBs). Ni preferentially dissolves from the matrix and redistributes, forming Ni-Sn-rich reaction products near the corrosion front. At 650 degrees C, dealloying is relatively mild, with limited grain detachment and largely retained grain morphology. With increasing temperature, dealloying accelerates, interfacial reactions intensify, the residual solid framework progressively breaks down, and corrosion products further dissolve and disperse into the liquid Sn. This work provides new insight into temperature-dependent Ni-based alloy dealloying in Sn, guiding strategies to improve material compatibility in CSP systems.

Negative stiffness (NS) structures have obvious advantages in attenuating low-frequency vibration. Although most existing NS structures exhibit good damping effects, their stability is poor, limiting their application in complex mechanical systems. To improve their damping and stability, a negative stiffness structure composed of rubber spring and elastic beam (NSS-RB) is proposed. Its elastic properties are studied via numerical modeling. Numerical and experimental results show NSS-RB has high static and low dynamic stiffness, achieving good damping and stability. Applied to a power battery package damping system, NSS-RB outperforms the rubber spring (RS) system in vibration reduction: the low-frequency vibration attenuation rate exceeds 90%, with good ride comfort and no instability.

The thin walled metal plates (TWMP) on top of a commercial vehicle body are easy to produce vibration and booming noise under the action of high-speed airflow, which reduces the sound quality inside the vehicle. Therefore, the effective control of the noise of TWMP is very important for vehicle comfort performance. Based on experimental, finite element, dynamic and fluid techniques, a method for identification, analysis and optimization of TWMP booming noise under high-speed airflow is proposed in this paper. The problem frequency, the noise source and the cause of booming noise inside the vehicle are identified by amplitude-frequency characteristics analysis and modal analysis. By establishing the dynamic model of damping patch, the matching method of damping patch is proposed. The simulation results are in good agreement with the experimental results, which shows that the method is correct. And the damping coefficient, attachment position and attachment area of the damping plate can be analyzed quickly and accurately by using the method, and the vibration and noise of TWMP can be reduced obviously.

A combined process of laser texturing and electroplating was developed to improve the shear strength of vacuumbrazed AISI 304 stainless steel (304SS) joints. Laser texturing created a mechanically interlocking interface by increasing the surface roughness, thereby improving joint adhesion. Meanwhile, an electroplating process deposited a uniform copper layer on the textured surface, mitigating filler distribution inconsistencies and ensuring more effective flow during brazing. This enhanced mechanical interlocking from laser texturing and uniform filler distribution from electroplating led to a significant improvement in joint performance, with the optimized shear strength reaching 331 MPa. These findings underscore the potential of combining surface microstructuring and electroplating for advanced vacuum brazing applications of stainless steels.

The casting CAE technology effectively predicts the occurrence of casting defects by simulating the filling and solidification processes of molten metal. In this study, the heat transfer coefficient at the interface between AlSi7Mg0.3 castings and Molding sand was determined through actual temperature measurements and reverse calculation experiments. Building on this foundation, a multi-objective optimization of process parameters for low-pressure casting of hollow control arms made from Aluminum alloy was conducted using Box-Behnken design, casting simulation technology, and optimization algorithms. The results indicate that, when the pouring temperature is set at 715 degrees C, the filling pressurization rate is 8.3 mbar/s, the top die temperature is 353 degrees C, and the bottom die temperature is 386 degrees C, the casting exhibits no casting defects. Furthermore, after undergoing T6 heat treatment, the dendritic morphology in the main body of the casting is effectively eradicated. This research offers novel insights and methodologies for optimizing the low-pressure casting process of large hollow thin-walled castings.

This paper presents a novel method for structural lightweight design of automotive safety components, exemplified by the aluminum alloy steering knuckle. This study aims to lightweight the aluminum alloy steering knuckle while ensuring its critical performance indicators remain unaffected through advanced computer-aided design and simulation analysis techniques. A finite element model is developed and subjected to comprehensive simulations under realistic load conditions to evaluate strength, stiffness, modal characteristics, and fatigue durability. With weight minimization and first-order modal frequency maximization as objectives, through rigorous sensitivity analysis, the structural size parameters of the aluminum alloy steering knuckle that significantly influence the target responses, including weight, modal frequency, and stress distribution, were identified as design variables. Based on this, a high-precision response surface model was constructed, and the Non-dominated Sorting Genetic Algorithm II (NSGA-II) was integrated for multi-objective optimization design. The resulting optimal design achieves a 5.6

For linear system, vibration response can be obtained by working load and vibration transfer function. However, for nonlinear systems, the vibration transfer function is variable, so the error of the existing methods is obvious. In order to improve the fitting precision of nonlinear system vibration response, a hybrid fitting method is proposed. That is, the vibration response is fitted by the vibration transfer function and the working load test. The influence of nonlinear parameters on the vibration transfer function is analyzed. A hybrid fitting method is used to identify the body acceleration on Class A, Class B and Class C pavement, and the analysis results are compared with the test results. The agreement between fitting results and test results is more than 90%. The results show that the hybrid fitting method proposed in this paper can significantly improve the fitting accuracy of nonlinear system vibration response.

Understanding the enhancement effects of graded design on the dynamic crushing behavior of honeycombs is crucial for engineering applications. This paper investigates the enhancing performance of a novel dual-directional graded honeycomb called modularized honeycomb (MH) under dynamic loading conditions. Finite element (FE) models of MH are developed and validated through drop weight impact tests. A theoretical model for predicting the dynamic plateau stress of MH is also derived. By analyzing both FE and theoretical results, it is concluded that for any average relative density and graded coefficient, the strength and specific plastic energy absorption of MH increase with crushing velocity, and MH consistently outperforms that of uniform honeycomb (UH). However, the enhancement coefficient, i.e., strength ratio between MH and UH, decreases as increasing crushing velocity. The underlying mechanism for this is uncovered based on the design principle and the theoretical model. Moreover, the enhancement coefficient and energy ratio exhibit insensitivity to average relative density under dynamic loadings. Overall, this paper reveals enhancement effects of modularized design on dynamic crushing behaviors of MH and provides insights into the differences between MH and UH, which could benefit development of excellent lightweight energy absorbers.

Vibration control is the key to development of high-speed and light-weight transmission system. There are many factors affecting the vibration, and the influence of misalignment is the most obvious. Therefore, it is important to understand the dynamic response of transmission shaft with misalignment. In previous studies, researchers studied the influence of plane angle misalignment. However, there are few researches on the effect of spatial misalignment on shafting vibration. In this paper, a numerical model of shafting with spatial misalignment is established. The influence of plane angle misalignment and spatial angle misalignment on the vibration is studied. The numerical and experimental results show that the vibration of shafting with spatial angle misalignment is bending-torsional coupled vibration, and the two kinds of vibration reinforce each other, and the torsional vibration is the main vibration. Compared with the influence of plane angle misalignment, the influence of spatial angle misalignment is more obvious..

In this study, a copper brazing filler metal coating is fabricated on a 304 stainless steel (304SS) substrate using an electroplating technique. The effect of using electroplated copper brazing filler metal coatings compared to pure copper foil of the same thickness for vacuum brazing of stainless steel joints is investigated. The microstructure and microhardness of the brazed joints are characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and a Vickers hardness tester. The shear strength of the brazed joints is measured using an INSTRON 5869 universal testing machine. The results indicate that the electroplated Cu coating is dense, predominantly with a single cubic phase, with a few copper particles aggregating on the surface. Under electroplating conditions of 20 mA cm-2 for 1 h, the coating thickness was 56 mu m. The shear strength of the brazed joint with this coating reached a maximum of 333.7 MPa, which is higher than that of a brazed joint with a 60 mu m thick copper foil, which exhibits a shear strength of 303.2 MPa. The shear strength of the brazed joints shows an initial increase followed by a decrease as current density and electroplating time increase. This study provides significant technical support for brazing complex shapes or precision components. It suggests a method to simplify the brazing process, reduce production costs, and enhance the strength of brazed joints. This study involves the fabrication of a copper brazing filler metal coating on 304 stainless steel using electroplating. The electroplated Cu coating is dense and consists mostly of a single cubic phase. The effects of electroplated coatings are compared to those of pure copper foil of the same thickness for vacuum brazing. The study demonstrates that electroplated coatings enable the brazing of complex shapes, simplify processes, reduce costs, and enhance joint strength.image (c) 2024 WILEY-VCH GmbH

As a key technique of vibration control, transfer path analysis (TPA) provides theoretical support for diagnosis, analysis, evaluation, and optimization of vibration in mechanical systems. The coupling phenomena often exists in the vibration transfer paths of complex mechanical systems, which makes most of the existing TPA methods unable to accurately analyze the transfer function of the coupled paths. The classical transfer path analysis (CTPA) is an effective method to solve the problem of path coupling, but it changes the inherent characteristics of the system, the results can not accurately reflect the vibration transfer characteristics of the system. In order to overcome the disadvantages of CTPA method, a decoupled transfer path analysis (DTPA) method is proposed in this paper, and the implementation process of this method is introduced by taking a hybrid mechanical system as an example. The results show that DTPA method can solve the path crosstalk problem and accurately calculate the transfer function of each path.

The design of the gear quantity and transmission parameters of a vehicle has large effects on its economical and power performance. This paper mainly researches the gear conditions (including the gear quantity and each gear’s transmission parameters) of two-gear and three-gear AMT (Automated Mechanical Transmission). This research uses Cruise software to build a multi-gear simulation model of a BEV (Battery Electric Vehicle) and adopts the LHS (Latin hypercube sampling) method to design an experiment plan and conduct a simulation experiment. This paper proposes a systematic method for influencing factor analyses and the optimization of transmission parameters, combining fuzzy theory, multiple regression, and particle swarm optimization. The research results show that the gear quantity allowing for optimal overall performance is three. The highest score obtained in the results of the simulation experiment for three-gear AMT is 11.15% higher than that of the two-gear AMT. The optimal design plan for the two-gear AMT is a small ig1 with a big k1, in which case the highest score of the regression model increases by 2.67% compared with that before modeling. The optimal design plan for the three-gear AMT is a big k1 with a big k2, in which case the highest score of the regression model increases by 12.78% compared with that before modeling. Then, this research uses PSO (particle swarm optimization) to further optimize the regression models and compares the difference between the highest scores in the results of the simulation experiment. The difference between the highest scores of the three-gear and two-gear AMT further increases to 21.95% after optimization. As shown in the results, the key factor influencing the performance of two-gear and three-gear AMT is gear quantity.

In the paper, the mechanism and key influencing factors of compound vibration are analyzed by establishing the dynamic mathematical model with 11 degrees of freedom, and the experiment method for identifying compound vibration is put forward. The sensitivity of influencing factors of compound vibration of the body is analyzed by establishing a rigid-flexible coupling dynamic simulation model. The results show that vertical vibration, roll vibration and pitch vibration are the main forms of the vehicle body vibration, front suspension stiffness and rear suspension stiffness not only are the key influencing factors of Z-direction vibration, but also are the key influencing factors of pitch angle. The key influencing factors of roll angle are lower control arm length L D and rear suspension damping Cr. By optimizing and improving the damping of the rear shock absorber, the Z-vibration, roll vibration and pitch vibration of the body are obviously reduced. The research results provide a theoretical basis and reference for mastering the composition and formation mechanism of compound vibration of vehicle body.

The transverse leaf spring (TLS) suspension has simple structure, convenient installation and low cost. And the suspension stiffness is optimized by changing the TLS fixing bracket position without changing TLS size, which makes the TLS suspension have higher application prospect. The dynamic modeling method is proposed for analysis of elastic characteristics of the TLS suspension. The trend of the TLS stiffness is theoretically expounded. And the stiffness, natural frequency, damping characteristic and vibration of the suspension are simulated and tested. The comparative analysis shows that the precision of numerical results is high, which also shows that the TLS suspension modeling method is correct. The results provide a basis for grasping the TLS stiffness trend and the suspension dynamic characteristics.

The subframe is a crucial load-bearing part of the chassis, playing a significant role in ensuring the safety and reliability of the vehicle. In this study, we aim to investigate the squeeze casting process of an integrated aluminum alloy subframe. Using relevant design criteria and casting theory, we have determined the optimal squeeze casting process for the whole subframe. The experimental factors for the subframe squeeze casting include pouring temperature, die temperature, filling velocity, and pressure holding time, while the response indexes are porosity, secondary dendrite arm spacing, and solidification time. These criteria were chosen based on their importance in determining the quality and mechanical properties of the casting. By studying the squeeze casting process of the integrated aluminum alloy subframe, we hope to improve the safety and reliability of chassis components. In this manuscript, the Box–Behnken design methodology was used to design the experiment scheme, and virtual casting simulation method is used to simulate the casting, and the input–output relationship model was developed. On this basis, the optimal process parameter combination was obtained by using the mayfly algorithm based on orthogonal and chaotic strategy (MAOLC). Simultaneously, the trial production test was carried out on the squeeze casting machine to verify the optimal parameters. X-ray inspection, metallographic structure testing, and mechanics performance testing show that the casting has no casting defects and has good mechanical properties.

The Uniform Honeycomb-filled Tube (UHT) is one of the composite structures that has shown huge potential in absorbing energy. In this paper, Uniform Honeycomb (UH) filler is replaced by an enhanced Modularized Honeycomb (MH). The biggest advantage of MH is that it can significantly enhance energy absorption without adding weight compared with its uniform counterpart. Finite element models are created, and then validated by theoretical models. The energy absorption of the Modularized Honeycomb-filled Tube (MHT) is compared with that of the empty tube and UHT. The results show that the MHT is superior to them in Specific Energy Absorption (SEA). It is also found that the tube can help the MH improve its deformation stability, which is the key of the MHT’s excellent energy absorption capacity. Then, effects of design parameters on the SEA of the MHT are investigated and discussed. The results show that the MH with a large graded coefficient is good for enhancing the SEA of the MHT. However, the SEA also relies on the match between the honeycomb filler and tube walls. The work could inspire designs of modularized filler with various types of cells and benefit the development of advanced energy absorbers with lighter weight and more excellent energy absorption capacity.

The design of new energy vehicle load-bearing structural components using traditional experience may lead to low material utilization efficiency. This makes it difficult to reduce the quality, or material shortage, which will increase the number of product design iterations and design cycle. Fortunately, the increasingly mature structural topology optimization technology can effectively solve this problem, and can provide a structural basic feature with high material utilization efficiency for parts according to the structural optimization objective. In addition, the rapid development of special casting technology makes it easier to process parts with complex shapes. Herein, a collaborative design method combining structural topology optimization design, material lightweight design and squeeze casting process was proposed to realize the lightweight of new energy vehicle load-bearing structural parts more effectively. The collaborative design method was applied to the steering knuckle design of a vehicle, and the results show that the method has a significant lightweight effect and can obtain the aluminum alloy steering knuckle with better quality.

The control of high-speed rocking vibration of steering wheel is very important for vehicle comfort performance. Among vibration control methods, the reasonable design of wheel alignment parameters is the most effective method. At present, the alignment parameters are obtained through quasi-static test. However, under high-speed driving conditions, the wheel alignment parameters change dynamically, which intensifies the vibration of the steering wheel. Therefore, it is more meaningful to study and control the dynamic characteristics of wheel alignment parameters. In order to analyze the dynamic characteristics of wheel alignment parameters and the problem of high-speed rocking vibration of steering wheel, the method of dynamic identification and dynamic control of alignment parameters is presented in the paper. By controlling the wheel dynamic unbalance and lateral force variations, the dynamic variation of the toe angle is significantly reduced, which reduces the vibration of the steering wheel.

为了确定最优的A356铝合金钳体支架压铸工艺参数,本文综合运用成形过程数值仿真、Taguchi正交试验设计以及信噪比分析三种方法.以最小孔隙率和二次枝晶臂间距数值(SDAS)为优化目标,对关键压铸工艺参数实施优化,包括模具初始温度、铝液浇铸温度、冲头压射速度和模具保压压力.研究结果表明:优化的工艺参数组合为模具初始温度275℃,铝液浇铸温度630℃,冲头压射速度0.5m/s,模具保压压力50MPa.使用优化工艺参数组合能够减少钳体支架的内部缩孔缩松铸造缺陷.

利用数值模拟对铝合金变速箱箱体挤压铸造过程进行分析,预测了原始工艺方案中箱体缩松缩孔缺陷的分布情况,通过分析其形成原因添加了合理的冷却系统.在此基础上运用正交试验对工艺参数进行了多目标优化.结果表明:优化后的箱体无缩松缩孔缺陷,二次枝晶间距减小到 36.37 μm.通过金相分析,验证了箱体挤压铸造工艺的正确性.