To reduce the use of fossil fuels, the adoption of battery electric vehicles (BEVs) using lithium-ion batteries has been increasing in internal combustion engine alternatives. Accordingly, significant efforts have been made to improve the manufacturing process of lithium-ion batteries within electric vehicles. In particular, the cutting process of lithium-ion batteries has been actively discussed as it is closely related to battery performance. Laser-based cutting enables a more precise and sustainable manufacturing process. The laser ablation threshold has been investigated in many studies to achieve high-precision laser processing. While laser parameters and ambient conditions have been examined to determine the laser ablation threshold, studies focusing on the effect of relative humidity remain insufficient. Thus, this study investigated the laser ablation threshold of aluminum foil under varying relative humidity conditions. First, a laser interaction chamber was fabricated to control the relative humidity during experiments. A scanning electron microscope (SEM) was then used to observe laser ablation craters and analyze the threshold. The variation of the laser ablation threshold with relative humidity revealed changes in the interaction between the laser and aluminum foil depending on the humidity level.

In recent years, the demand for lightweight parts has been gradually increasing, particularly in the E-mobility industry. Among lightweight materials, aluminum alloys are highly beneficial for improving the fuel efficiency of automobile engines due to their lighter weight compared to iron-based materials. As electric vehicles become more prevalent, aluminum alloys are also extensively used in components such as battery housings and EV platform frames. To enhance productivity, aluminum parts processing companies require Polycrystalline Diamond (PCD) cutting tools for high-speed and ultraprecision processing. PCD cutting tools are known for their excellent cutting performance and wear resistance in highspeed aluminum machining, and they are anticipated to have significant growth potential in the global cutting tool market. In this study, we manufactured three types of PCD cutting tools (Drill, Endmill, and Reamer) using a self-developed brazing device and analyzed the machining surface quality through experiments. The results showed that the brazing joint quality of the PCD cutting tools was high, and the differences in surface roughness values under various machining conditions were minimal, confirming no issues with machining performance. Future research will focus on evaluating machining precision and tool life through comparative experiments with advanced PCD cutting tools from overseas.

A feasibility study of electrically assisted solid-state spot joining (EASSJ) of dissimilar aluminum alloys for automobile structures was conducted. EASSJ of dissimilar automotive aluminum alloys (AA6451 and AA6014) was conducted by simultaneously applying step-by-step current and compressive load to the faying interface (lap spot joining), while the temperature was controlled to be lower than melting points of joining alloys. To evaluate the soundness of the joint, a nugget pull-out fracture mode under shear tensile test was set as a criterion. Microstructure analysis was also conducted to evaluate characteristics of the joint. Experimental results suggest that the EASSJ is clearly feasible in joining dissimilar aluminum alloys for automobile structures.

In this study, based on directed energy deposition (DED) technology, one of the additive manufacturing technologies, a porous material fabricated by mixing various aluminum alloys and foaming agent was manufactured. First, the foaming agent formed pores inside the deposited materials and differences in foaming characteristics were observed depending on the type of aluminum. Also, the foaming characteristics according to the laser power, which is a representative process variable, were analyzed. As a result, a closed-cell porous material with a maximum porosity at a laser power of 1,100 W was manufactured. Results of the compression test showed that the porous material made by the pores generated therein collapses to absorb energy, and the internal pores disappear to become high density. Therefore, Young’s modulus and yield stress were reduced by the pores inside the sample of pure aluminum and Al6063. However, it was found that the specific energy absorption, which is an advantage of the foamed materials, increased compared to non-porous materials. The findings of this study confirmed that it was possible to manufacture DED-applied foam materials using aluminum powder and a foaming agent.

The adhesive bonding technology of carbon fiber reinforced plastics (CFRP) and aluminum alloys, is one of the lightweight joining technologies for automobiles. The strength and properties of the bonded joint, depend on the surface of the bonded part that the adhesive touches. Thus, proper surface treatment is one of the most important steps in the bonding process. The laser surface treatment of carbon fiber composites is a new form of green and environmental surface treatment technology, which can effectively clean coatings and pollutants on the surface of materials. It is also possible to improve the bonding shear strength, by changing the microstructure and roughness of the material surface through laser micro texture processing, to form a mechanically interlocked structure. In this study, a pulsed laser was used to treat the surface of CFRP. By changing the scanning line spacing during laser micro texturing, the effect of laser micro texturing on the surface morphology of CFRP and the strength of aluminum alloy bonded joints was investigated. Results show that in the laser micro texturing process, when the scanning line spacing was 0.3 mm, the maximum tensile shear strength was 14.5 MPa, approximately 200% higher than that without laser treatment.

The present investigation studies the effects of heat treatment temperature on the corrosion behavior of cold worked 6111 aluminum alloy. The specimens were cold worked at different cold working ratios, namely, 10, 20, and 40%. They were then heat treated at 100, 200, and 400°C. Corrosion tests were performed using tap water with 0.01 M sodium hydroxide, as a corrosive medium, and the weight loss of the corroded specimens plus the corrosion rates were then calculated. Experimental results showed that corrosion rates depended on the amount of cold working percentage and the heat treatment temperature. Corroded surfaces were also photographed and analyzed. The graphs revealed large numbers of corrosion pits, in addition to crevice corrosion and fine grains of rust, and these rusts were cultivated to scales that were detached from the surfaces and were subjected to corrosive medium.

Anodic aluminum oxide (AAO) is widely used in various industrial fields to increase the mechanical property or corrosion resistance of the product surface. In this study, mechanical properties were measured according to the thickness of AAO through the nanoindentation test. The maximum indentation load, elastic modulus, and hardness were measured for different thicknesses of AAO. It was confirmed that the majority of the mechanical property values increased with the thickness. Various fracture shapes based on the thickness were analyzed by observing pressure marks on the surface using FE-SEM equipment. Apparently, it is proposed that the optimum AAO thickness with desired mechanical properties can be obtained, which is expected to possess immense economic value as per the optimization of the production time of AAO based products.

The heat-sealing strength of pouch film greatly affects the reliability of the lithium ion secondary battery. In this paper, the researchers investigated and evaluated the properties of the heat-sealing strength of pouch film, such as heat, pressure, time, thickness of the heat-seal, and the polypropylene material. The heat-sealing strength showed a high value at 180℃ for 3 seconds. However, under the conditions of higher temperatures and longer times, deformation and bulging of polypropylene were observed. The heat-sealing strength tended to increase when decreasing heat-seal thickness. The heat-sealing strength varied according to the type of polypropylene. In addition, to avoid defects that may have occurred in the process of manufacturing the lithium ion secondary battery, the heat-sealing strength in the state where the impurities remained was evaluated.

This paper studied the adhesive strength and electrolyte resistance of the pouch film according to the kind of the extruded resin, which is the basis of the numerous variables in extrusion lamination. After preparing a pouch film by using various extruded resins, we measured the adhesive strength and electrolyte resistance between the aluminum foil and the CPP film. The minimal difference was observed between the adhesive strength with the extruded resin. Also, the extruded resin used in the experiment did not satisfy the electrolyte resistance. An electrolyte resistance was obtained by addition of the functional resin to the extruded resin. The addition of functional resins resulted in improved adhesive strength and electrolyte resistance, that were measured to be approximately 1300 gf/15 mm and 800 gf/15 mm, respectively, at 85℃ for 7days.

This paper presents a construction method regarding a tubular nano-mesh for which the anodic oxidation of aluminum (Al) wire is used. The first step of tubular-nano-mesh production is Al-wire anodization. A new anodizing device was made for the wire-based uniform anodization for this study, and a high-purity (99.999%) Al wire with a 2 mm diameter was used. Also, an electrolytic solution was used as a 0.07 M oxalic acid, while the electrolytic-solution temperature was maintained at -3℃. While the applied voltage and the process time were varied, the AAO (Anodic Aluminum Oxide) characteristics of the Al wire were observed. When 60 V was applied to the wire, alumina cracks were not evident, whereas the application of 100 V produced alumina cracks; this is because the growth rate of the nano-pore voltage affected the alumina shape. For the subsequent construction of the tubular alumina structure, an Al-etchant (HCl + H2O + CuCl2 + 2H2O) etched-Al portion of the anodized wire was employed. The final step is a pore-widening process that is implemented through the hole channel. The anodized wire was dipped in the alumina etchant, and the pore-wall removal was checked over time.

In this study, the intention is the determination of the optimum laminate conditions for the improvement of the chemical resistance of the aluminum-pouch films that are widely used as a packaging material for the secondary battery. Here, the properties including the initial adhesive strength and the electrolyte resistance between the metal-film layer with aluminum and the sealant layer with cast polyprophylene (CPP) film were investigated. Regarding the lamination condition, the lamination temperature, speed, and pressure conditions were changed. A roll-to-roll dry lamination-coating system was used in the surface-treatment agent coating, adhesive coating, and film lamination. For the lamination conditions of the aluminum and CPP films, the initial adhesive strength of the laminated-pouch film manufactured with a 110oC temperature and a 6.0 M/min line speed is 1200 gf/15 mm. The measured adhesive strength of the 85oC electrolyte resistance after its immersion for 7 days is 600 gf/15 mm.

Chemical mechanical polishing achieves surface planarity through combined mechanical and chemical means. The role of the chemical reaction is very important in a metal CMP like aluminum. The slurry used in aluminum CMP typically consists of oxidizers, a chelating agent, corrosion inhibitors, and abrasives. This study investigates the effect of oxalic acid as a chelating agent for aluminum CMP with H2O2. To study the chemical effect of the chelating agent, the two methods of a polishing experiment and an electrochemical analysis were used. Lastly, it was confirmed that the optimum concentration of oxalic acid significantly improved the removal rate and surface roughness of aluminum.