Welding tests are carried out on flat copper wires for stator of new energy vehicles’ drive motors by using two processes, ring spot laser welding and TIG welding. Moreover, the welding process and the performance of the joints are investigated and analyzed. The results show that the optimal process of flat copper wire laser welding is 2 500 W for the center core power, 1 500 W for the ring core power, 290 mm/s for the welding speed, and +5 mm for the defocusing amount, and the obtained joints are well formed without weld defects such as pores, etc.; the optimal process parameters of TIG welding are 140 A for the welding current, 150 mm/s for the welding speed, and a small amount of shrinkage holes exists in the obtained joints. The maximum shear strength of the joint obtained by the ring spot laser welding process is 132 MPa, and the maximum hardness of the joint appears in the center of the weld, which is about 140 HV0.2; while the maximum shear strength obtained by TIG welding is 110 MPa, and the maximum hardness of the joint appears in the center of the weld, which is about 128 HV0.2. The welded joints obtained by ring spot laser welding are better than the TIG welded joints in the organization, morphology, and mechanical properties, and they are more suitable for the welding of flat copper wire.

Currently, with the continuous improvement of engine performance, the working environment of the valve guide has become more harsh, so the failure problem of the valve guide has become more and more common. A comparative analysis of the durable and failed components of the engine exhaust valve guide is conducted to identify the causes of material failure. The wear resistance, microstructure, and porosity of the valve guide are studied. The results show that the wear test results of the 2 specimens are consistent with the bench test results, and the failed specimen experiences wear serious. The microstructure of both is consistent with a small amount of pearlite and a large amount of irregular pearlite and alloy phase and pores. The porosity results indicate that the durable specimen has a higher porosity ratio, storing more oil and with a density meeting the standard. However, the failed specimen has a large hole with a diameter of 100 μm, which reduces its wear resistance. Therefore, the cause of wear failure is identified as lower porosity and the existence of larger pores.

Taking the cast iron rear axle housing of commercial vehicle as the research object, the bench test fatigue life data analysis and processing of several axle shell types are carried out. And the number of loading cycles at failure is obtained. Using the finite element fatigue analysis method based on time history load, the fatigue equivalent stress of the cast axle housing under the corresponding load cycle is obtained. Then the S-N curve of the cast axle housing is fitted by combining the fatigue equivalent stress and number of failure cycles. The results show that, the current analysing cast axle housing has a problem of low defect control level. The manufacturing process level needs to be improved. Moreover, the importance of formulating defect level classification during design is proposed. The application of the finite element fatigue analysis combined with the test data can effectively predict the fatigue life of the newly designed structure on the premise of stable process level. The finite element analysis results and manufacturing process can be combined effectively to expand the practicability of the bench test data.

At present, the automotive market is reshaped with the coexistence of pure electric and hybrid models, and the automotive factories are facing higher quality requirements and faster manufacturing response for flexible manufacturing, equipment sharing, personalized customization. By combining work practice and benchmarking global benchmark automakers, this paper provides key manufacturing factors for adapting multi-energy vehicle assembly processes for efficient co-production through the application of strategic approaehes to advanced teehnology sector including lean production mode, digital simulation, user experience, and carbon neutrality, which can be used as reference for the construction of future highly efficient hybrid assembly factories.

Because of high integration, lightweight, good rigidity and the other advantages, the application of integrated high-pressure casting aluminum alloy structural parts in the passenger car body is gradually increasing,and the size of high-pressure casting aluminum alloy structural parts is also developing towards large scale. At the same time, the development of large-scale high-pressure casting aluminum alloy structural parts is bringing greater challenges to the connection technology. The Paper describes the typical application parts of high-pressure casting aluminum alloy for passenger car body, analyzes the difficulties and the connection technology corresponding strategies for applying large-sized high-pressure casting aluminum alloy structural parts. The development trend of high-pressure casting aluminum alloy structural parts and the new requirements for connection technology are also prospected.

The radiator bracket of a vehicle fractured and failed during a vehicle road test. To find the causes of fracture failure, macroscopic inspection, fracture morphology analysis are performed, and numerical simulation method is adopted to perform simulation analysis, and it is found that the irrational structure design leaded to excessive stress in some areas exceeding the yield limit. Then, according to the simulation results, optimization measures are proposed for stress concentration area. After structural optimization, the optimized bracket structure is obtained. The optimized structural strength simulation shows that the maximum regional stress level of the bracket structure is 375 MPa under the maximum load, which is lower than the yield strength of the material (450 MPa), meeting the strength performance requirements.

A new Al-5C intermediate alloy is prepared by in-situ reaction sintering method. Optical Microscope (OM), X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM) are used to study the effect of the preparation process on the microstructure of Al-5C intermediate alloy and the grain refinement of Mg-Al alloy. The results show that the in-situ reaction sintering method improves the wettability of Al and C, and the reaction degree of Al-C is related to milling time, sintering temperature, sintering time and pressing method. Prolongation of milling time, increase of sintering temperature or appropriate extension of sintering time can promote the Al-C reaction, resulting in the formation of fine Al₄C₃ particles. Al-5C intermediate alloy can effectively refine the microstructure of Mg-3Al alloy, and the best grain refinement effect is obtained when the addition amount (mass fraction) is 2%.

In order to trial produce qualified carbon fiber engine hood products and solve technical issues in the manufacturing process, CAE technology method is adopted to optimize and simulate the product structure, determine the manufacturing technology scheme, optimize the product layering technology data, autoclave molding parameters and mold tooling development method, and obtain the development technical specifications and process trial production experience of carbon fiber composite material products. The development and manufacturing process of carbon fiber composite engine hood are complex, and technical specifications and trial production experience have a significant impact on product quality.

In order to study the effect of supply chain on vehicle whole life cycle carbon emission, this article collects the carbon emission data of the supply chain through China Industrial Carbon Emission Information System (CICES), aims to study and analyze the carbon emission of the whole life cycle of a vehicle. The results show that the upstream and downstream supply chains such as raw material production, parts production and the using stage of the vehicle are the main factors affecting the carbon emission of the life cycle of the vehicle, and suggestions on carbon emission management of the supply chain are put forward.

In order to address the issue of microbes slimegenerated by bacteria and microbial breeding sticking on the car bodies and affect E-coat quality, taking bacteria and microbial breeding in pretreatment phosphorization and E-coat process of a painting shop and management as example, this article explores the management of bacteria and microbes from 2 aspects including precautions during production and maintenance during shutdown. Precaution during production refers to improving water rinsing station turnover rate and improving filtration efficiency to prevent microbe slime from contaminating car bodies, whereas maintenance during shutdown refers to dismantling and deep cleaning, combined with bactericide, hot water rinsing and special rinsing tool to form an effective management strategy.