The effects of alkyl acid surfactants with different carbon chain lengths (decanoic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid) on the properties of CeO₂-ZrO₂-Y₂O₃-La₂O₃ (CZ) materials were studied and analyzed, and the underlying mechanism of surfactants in building high performance CZ materials has also been revealed. The results of N₂-adsorption/desorption, OSC, H₂-TPR, and catalyst activity show that the addition of all surfactants with different carbon chain lengths during the nucleation stage of nanocrystals can increase the initial grain size of nanocrystals, thereby reducing the driving force of sintering. At the same time, the introduction of surfactants produces more oxygen vacancies in the material, thereby improving its redox performance. Among them, dodecanoic acid plays the most prominent effects improving the thermal stability and redox performance of CZ materials, the resultant CZ exhibits the lowest loss rate of specific surface area of 46.3%, the lowest reduction peak temperature of 497℃, the highest utilization rate of Ce of 39%, and consequently the best catalytic activity of its supported Pd-only TWC.

PA66 material has good heat resistance and is widely used in heat-resistant parts of lamps. However, because it is prone to thermo-oxidative decomposition, the small molecular substances decomposed are easy to form fog deposits, which affect the appearance, performance and service life of lamps. Therefore, the study of low-volatile PA66 composites is an urgent issue to be solved. This paper investigated the effects of antioxidants, molecular sieves, PA10T, processing technology and other factors on the volatility of PA66 composites under thermo-oxidative aging, and analyzed the main components of volatiles. It concluded that the copper salt (0.5 wt%)+ PA10T (30 wt%)+double vacuum scheme had better fogging, and proved to meet the requirements.

Carbon Fiber Reinforced Polymer (CFRP) is a material with excellent mechanical properties. The application of bonding CFRP parts with body has not been realized in mass automobile production in China. The article described the performance test on CFRP parts bonding with aluminum material and the optimization of process flow. The bonding process flow and process parameters of each process of CFRP on ES6 were ultimately determined based on the test of the curing strength of adhesive under different conditions and the influence of external factors on the adhesive bonding strength, Thus, for the first time, CFRP was applied to the body structure of new energy vehicle on a large scale (production capacity 20 job/hour) in China.

This paper conducted an in-depth study on the internal cavity corrosion of new energy control modules. The paper firstly analyzed the key factors contributing to corrosion in the cooling system cavity of conventional fuel vehicles. Through a plasma concentration orthogonal test, this study simulated the equivalent ion concentration of the cooling medium to identify the influential corrosion factors. Subsequently, by comparing the corrosion rates of aluminum substrates under different corrosive media, this paper demonstrated the applicability of traditional test methods to new energy control systems. A cavity blockage test was designed to verify the functional failure of the cooling system under affected conditions caused by corrosion. Finally, based on the investigation of internal cavity corrosion in new energy control systems, evaluation criteria for conducting internal cavity corrosion test within the company were developed.

In order to eliminate abnormal sound of the knuckle cone ball stud of a passenger car on proving ground test, this paper proposed a new method based on virtual simulation. Firstly, the ball stud contact area variation tendency was simulated and the contact area critical preload was identified according to limit value of the road load data; then the residual preload under alternate working condition was simulated, and the residual preload was controlled larger than critical preload to avoid large contact area separation which will cause abnormal sound; finally, the tightening process was determined through joint test. The results show that this method can redefine the tightening torque, and the abnormal sound problem was eliminated successfully.

In order to achieve traceability management of quality issues in stamping parts, the structure, principles, and advantages and disadvantages of mold mechanical coding technology and equipment laser coding technology were analyzed. Mechanical coding is installed on the mold, and online replacement results in production line shutdown. The coding time is accurate to weeks; Laser coding is integrated with the production line, without the need for stopping the production line to change labels, and the coding time is accurate to the parts.Different coding methods were selected according to different application conditions to meet the precise quality traceability control of stamping parts from single batch to single piece. At the same time, through digital means, various fields of coding information are connected, achieving tracking from stamping profession to vehicle quality traceability information binding.

When the exhaust pipe is welded with the flange, the welding deformation of the flange affects the tightness of the exhaust pipe assembly. In order to avoid excessive welding deformation of flange during manufacturing, the FEA model was established with the moving Gaussian heat source to simulate flange welding process. After analyzing and comparing the temperature field, stress and strain results of flanges under different constraint conditions and different welding parameters, the solution that can effectively reduce the welding deformation of flanges in the production and manufacturing of exhaust pipes was determined. This paper proposed suggestions of welding electric current, welding speed and heat source radius, which provided theoretical basis for the optimization of welding process of exhaust pipe flange.

Based on the Gissmo damage failure model, the failure parameters of 6082 automotive aluminum alloy profile were obtained by numerical parameter inverse method. The reasonability of the Gissmo damage failure model of 6082 aluminum alloy was verified by the quasi-static three-point bending test of the aluminum alloy impact beam. Firstly, the hardening curve of the 6082 material was obtained by quasi-static uniaxial tensile test, and the curve was extrapolated by Swift-Hockett-Sherby (SHS) law. Secondly, quasi-static tests (shear, uniaxial, central hole, notch, three-point bending, cupping) under various stress states were carried out, and Gissmo failure parameters were obtained by numerical inversion of test combined with simulation. Finally, the quasi-static three-point bending test of 6082 aluminum alloy impact beam was designed to verify the reasonability of Gissmo model. The test result shows that the Gissmo damage failure model of 6082 aluminum alloy proposed in this research, including hardening curve, failure strain curve, instability curve and mesh-size regulation curve, can predict the failure behavior of 6082 impact beam.

In order to address the issue of failure fracture of balance suspension leaf spring seat of engineering vehicle, this paper analyzed the balance suspension leaf spring seat by process analysis, fracture analysis, metallographic examination, strength test, hardness test and material fatigue limit testing. The results show that the material used in the balance suspension leaf spring seat meets the standard requirements, and the failure modes include multi-source high stress and low cycle bending fatigue cracking, the crack originates from the rounded root between the balance suspension leaf spring seat and the U-bolt, which is thick and easy to produce defects like shrinkage and porosity in the production process. In the structure, this position is the balance suspension leaf spring seat under the greatest stress position and a dangerous section of the part.

In order to improve the service life of spot welding electrodes, TiB2-reinforced copper matrix composites were prepared using a multi-step method. The physical phase and microscopic morphology of the TiB2-reinforced copper matrix composites prepared by the multi-step method were analyzed using X-ray diffraction (XRD), metallographic microscopy and scanning electron microscopy (SEM) characterization. By measuring the mechanical property indexes of the composites, it was found that the copper matrix composites prepared by the multi-step preparation had better comprehensive mechanical properties. The copper matrix composites prepared by the multi-step method were processed into spot welding electrodes, its life test results were the highest compared with other comparison samples, with a life time of 1 500 solder joints, which was 2.6 times longer than the life time of common chromium zirconium copper spot welding electrodes.

In order to shorten the cycle of product, design and developent, procurement and production, construction of a flexible, efficient, low-cost and high-quality manufacturing operation system, digital twin technology is crucial. This article used an automotive welding production line as an example to elaborate the process of setting up a digital twin factory in Tecnomatix software. Using Tecnomatix series software, the digital model and process information were imported in the pre-planning process, the 3D process layout was carried out in advance, the accessibility of connection processes such as solder joints and gluing was simulated, the spatial static and dynamic interference as well as offline program output were analyzed and solved. Utilizing digital twin technology, the mapping and correlation of real factories in the simulation environment was realized. As a result, the on-site installation and commissioning was accelerated, the project cycle was reduced, the efficiency and quality of production line planning and design were improved.