The Application of Aluminum Alloy Materials in Automobile Lightweight
Aluminum Alloy in Automobile Lightweight
(1) Cast aluminum alloy
Many elements can be used as alloy elements for casting aluminum alloys, but only Si, Cu, Mg, Mn, Zn, and Li are of great significance in mass production. Of course, what is widely used in automobiles is not the simple binary alloy mentioned above, but the simultaneous addition of multiple elements to achieve good comprehensive performance.
The automotive industry is the main market for aluminum castings, such as Japan, where 76% of aluminum castings and 77% of aluminum die castings are automotive castings. Aluminum alloy castings are mainly used in engine cylinder blocks, cylinder heads, pistons, intake manifolds, rocker arms, engine suspension brackets, air compressor connecting rods, transmission housing, clutch housing, wheels, brake parts, handle and cover housing parts, etc.
Defects are inevitable in aluminum castings, and die-casting parts cannot be heat treated yet. Therefore, the use of aluminum alloys to produce castings with high strength requirements is limited. For this reason, improvements have been made in the production process of castings, and the casting forging method and semi solid forming method will be more commonly used processes in the future.
(2) Deformed aluminum alloy
Deformed aluminum alloy refers to aluminum alloy plates, strips, extruded profiles, and forged materials, mainly used in automobiles for body panels, body frames, engine radiators, air conditioning condensers, evaporators, wheels, decorative parts, and suspension system parts.
Due to the significant lightweight effect, the application of aluminum alloys in car bodies is expanding. The Japanese Honda NSX, which started selling in September 1990, features an all aluminum load-bearing body that is 200kg lighter than the same body made of cold-rolled steel plate, attracting worldwide attention. The aluminum material used for the entire NSX vehicle reaches 31.3%. For example, on an all aluminum body, the outer panel is made of 6000 series alloy, the inner panel is made of 5052-0 alloy, and the majority of the skeleton is made of 5182-0 alloy; Due to the high requirements for strength and stiffness of the side door frame, an alloy based on 6N01 alloy with appropriately adjusted Mg and Si content was used. In Europe and America, 2036 and 2008 alloys are also used as interior and exterior panels for car bodies.
Typical Applications of Aluminum Alloy Materials in Automobile Lightweight
Lightweight body materials
The lightweight technology of car bodies mainly includes the use of lightweight materials, lightweight design of structures, and the application of advanced forming processes. The use of lightweight materials is the mainstream of vehicle body lightweight, mainly divided into two categories: one is the use of high-strength materials, such as high-strength steel and high-strength stainless steel; Another type is lightweight materials, such as aluminum/magnesium alloys, engineering plastics, carbon fibers, new types of glass, ceramics, and various composite materials.
Aluminum alloys have the characteristics of low density (about one-third of the density of steel), light weight, good formability, and recyclability. Research has shown that compared to traditional steel, when the same mechanical performance indicators are achieved, the mass of aluminum alloy used is 60% less than that of steel; Under the same impact conditions, aluminum alloy plates absorb 50% more impact energy than steel plates. Based on the important role of aluminum alloy materials in the lightweight propulsion process of automobiles, their application scope in automobiles has also become increasingly broad, expanding from the initial engine cylinder block, transmission housing, and wheel hub to various important components of the vehicle body. Naturally, this has prompted various automotive companies to increase their investment in the research and development of new deformed aluminum alloy materials. Anhui Jianghuai Automobile Co., Ltd. (hereinafter referred to as "Jianghuai") uses some aluminum alloy plates for its body, as shown in Table 1.
Technical characteristics of aluminum alloy materials
Aluminum alloy has significant advantages such as light weight, strong corrosion resistance, good durability, and reducing pedestrian impact injuries. The aluminum alloys used for car body panels mainly include 2000 series, 5000 series, 6000 series, and 7000 series alloys. Among them, the 5 series and 6 series are the most suitable substitutes for steel plates: the 5 series is a heat treated non reinforcing alloy with good formability, which can be used for complex shaped car body parts, mainly for internal covering parts; The 6 series is a heat treatable strengthening alloy suitable for areas with high strength and stiffness requirements such as outer panels, mainly used for automotive exterior panels.
Aluminum alloy connection technology
The application of lightweight materials in vehicle bodies not only reduces the weight of the vehicle body, but also puts forward higher requirements for corresponding connection technologies. The traditional welding methods for car bodies are generally spot welding and CO2 welding, with resistance spot welding technology accounting for about 75% of car body manufacturing and being widely used. Resistance spot welding is difficult to ensure the welding quality of dissimilar metals, especially for the welding of aluminum and magnesium alloy materials. Aluminum has a lower resistance than steel and a higher thermal conductivity. Resistance spot welding requires four times the current of the spot welded steel, which consumes a lot of energy and is difficult to ensure the welding quality; Traditional CO2 welding cannot effectively save the welding problem of dissimilar metals, and cannot guarantee the welding quality of thin plates, making them prone to deformation after welding.
Self piercing riveting connection (SPR)
SPR is a cold joining technique used for two or more types of metal sheets. As shown in Figure 2, under the action of external forces, the rivets penetrate the first and middle layer materials, and flow and expand in the bottom layer materials, forming a permanent plastic deformation rivet connection process that is embedded with each other. After connection, one side is relatively flat and one side protrudes into a cylindrical shape.
As a mechanical cold forming connection technology, SPR has the following advantages: it can achieve the connection of multiple materials; The strength of aluminum riveted joints is higher than that of spot welding of equal thickness aluminum; The process time can be controlled within 4 seconds. The limitations of SPR are that it requires dual gun entry space, different material combinations require different rivets, and the equipment is expensive. The investment cost for a set of equipment is about 900000 yuan.
The self piercing riveting process has the following characteristics compared to other connection technologies:
(1) It is one of the best connection processes for connecting different types of lightweight materials by combining two or multiple layers of plates with different materials, thicknesses, and strengths;
(2) No thermal effect, can be used for connecting coated or coated plates without damaging their coating layer;
(3) Compared with traditional riveting technology, it has high production efficiency, less equipment investment, and low energy consumption cost;
(4) Safe and environmentally friendly, with no heat, smoke, sparks, dust or debris generated during riveting;
(5) The quality of riveting is continuously stable, with high repeatability. The quality of riveting points can be visually inspected;
(6) Can be used in combination with adhesive technology.
Self piercing riveting equipment is generally divided into two types: hydraulic system and electric servo system. Among them, electric servo system has many advantages such as good riveting quality, high work efficiency, simple and reliable structural design, strong continuous working ability, and long equipment life. Currently, it is widely used in aluminum alloy vehicle bodies. In order to meet the usage requirements, a complete set of electric servo type self piercing riveting system consists of two major parts: self piercing riveting control system and self piercing riveting execution system. The self piercing riveting execution system also includes power supply mechanism, transmission mechanism, C-type pliers, riveting nose component, secondary power mechanism, ratchet nail supply system, riveting mold and support components and other accessories.
Jianghuai has also carried out process development and research on the inner and outer plates of aluminum alloy hair covers. Figure 3 shows the actual self piercing riveting of the hair cover inner plate assembly. Taking the inner plate of the hair cover as an example, the original material of the inner plate was DC03, and the weight of the part was 10.563 kg. After changing the material to 5182 aluminum alloy, the weight of the part was 5.184 kg, with a weight reduction ratio of 50.92%.
Cold Metal Transition Technology (CMT)
CMT is a new MIG/MAG welding process with extremely low welding heat input, which can weld plates as thin as 0.3 mm and achieve dissimilar connections between steel and aluminum. CMT is developed based on the short circuit transfer method, which assists in droplet transfer through the mechanical withdrawal of welding wires. The process can be accurately controlled, and the short circuit transfer cycle is constant, not affected by random variables. Due to the almost zero current during CMT droplet transfer, spatter is reduced, and welding quality is high. The process principle of CMT technology is shown in Figure 4, which is that the aluminum side is fused, the steel side is brazed, and the base metal is not melted; The required thickness of the galvanized layer on the galvanized sheet (>10 μ m) .
The main problem with connection is that brittle phases are easily formed at the joint, and the fewer brittle phases, the better the joint performance. One of the main factors determining the brittle phase is the heat input during welding. The lower the heat input, the less brittle phase is produced. So the CMT process can effectively achieve the welding of steel and aluminum. The physical image of the weld appearance is shown in Figure 6.
Laser welding technology
Laser welding is a high energy density welding method that uses laser as an energy carrier. Laser welding radiates a high-strength laser beam to the surface of a metal, and through the interaction between the laser and the metal, the metal is melted to form welding. Among them, aluminum alloy laser welding is currently being applied more and more widely.
The characteristics of aluminum alloy laser welding technology include: the need to use aluminum welding wires; Non contact welding with minimal deformation; Good welding quality, with weld strength equal to or exceeding that of the base material; It can achieve welding between different models and dissimilar metals, especially suitable for (ultra) high-strength steel plates and aluminum alloys; The overlap edge is shorter than traditional spot welding, which is beneficial for lightweight and cost reduction of the vehicle body.
The development level of the automotive industry is one of the important indicators of a country's level of development, and the lightweight of automobiles is an inevitable trend in the development of the automotive industry. To achieve lightweight body design, it is crucial to solve the connection technology problem of new materials while optimizing the structure of the body design and researching and applying new materials. Currently, aluminum alloy connection technology is becoming increasingly mature, and the corresponding connection processes have been effectively verified.
Aluminum alloys for automotive wheel hubs
The wheel is an important component of a vehicle that carries loads. In addition to being subjected to positive pressure, it also bears the interaction of torque during vehicle startup and braking, as well as irregular forces from various directions such as turning and impact during driving. During high-speed rotation, the wheel also affects the stability, operability, and other performance of the vehicle. The quality of the wheels is closely related to the various performance of the car, and the safety and reliability of the entire vehicle largely depend on the performance and service life of the installed wheels.
Compared with steel car wheels, aluminum alloy car wheels can better meet the requirements of good wear resistance, aging resistance, air tightness, good uniformity and mass balance, small rolling resistance and driving noise, exquisite appearance and decoration, high dimensional accuracy, light weight and small imbalance, good fatigue resistance, convenient folding and installation, and good interchangeability.
At present, aluminum alloy materials are commonly used for car wheels, but most heavy-duty vehicles such as trucks and buses still use steel wheels due to their heavy load and high comprehensive performance requirements for wheels.
The manufacturing processes of aluminum alloy wheels mainly include casting, forging, stamping, spinning, semi-solid die forging, etc. Among them, the most commonly used forming methods are casting and forging.
Low pressure casting mainly uses Al Si Mg series alloys. Ordinary cast aluminum alloy wheels can meet the performance requirements of car wheels, but cannot meet the requirements of heavy-duty vehicles such as trucks and buses. Ma Chunjiang et al. compared the microstructure and mechanical properties of ordinary cast aluminum alloy wheels with those of squeeze cast aluminum alloy wheels. The results showed that the mechanical properties of squeeze cast aluminum alloy wheels were higher than those of cast aluminum alloy wheels, and the bending fatigue performance, radial fatigue performance, and impact resistance of squeeze cast aluminum alloy wheels could meet the requirements of heavy-duty vehicles.
Simply put, gravity casting mainly relies on the gravity of aluminum water itself to fill the mold, which is a relatively early casting method. This method has low cost, simple process, and high production efficiency. However, during the pouring process, inclusions are easily trapped in the casting, and sometimes gas can also be trapped, forming porosity defects. The wheels produced by gravity casting are prone to shrinkage and porosity, and their internal quality is poor. In addition, the limitation of aluminum liquid fluidity may also lead to low yield of wheel hubs with complex shapes. Therefore, the automotive wheel rim manufacturing industry has rarely used this process.
The forging method is one of the earliest applied aluminum alloy wheel forming processes. The strength, toughness, and fatigue strength of forged aluminum alloy wheels are significantly better than those of cast aluminum alloy wheels, and they also have advantages such as good corrosion resistance, precise size, small processing volume, and strong performance reproducibility. It mainly uses Al-Mg alloy and Al-Si-Mg alloy. 5xxx aluminum alloy is the most commonly used deformed aluminum alloy in wheel forging, mainly including 5052-O, 5154-O, 5454-O, 5083-O, 5086-O. 5xxx forged aluminum alloy wheels have high corrosion resistance and are suitable for manufacturing wheels that work in extreme environments. Another commonly used aluminum alloy in wheel manufacturing is 6061-T6. The Mg2Si strengthening phase formed by Mg and Si elements can significantly improve its mechanical properties. After homogenization treatment at 565 ℃/4h-6h, the majority of Mg and Si in 6061 alloy ingots can be solidly dissolved in aluminum, which not only reduces the forging temperature but also improves the forging performance. Long Wei et al. used the three-dimensional finite element software Deform-3D to simulate the forging process of 6061 aluminum alloy wheels, analyzed and compared the stress-strain states at different positions of the wheel hub and their relationship with mechanical properties. The results showed that the position with larger cumulative stress-strain in the wheel hub had better mechanical properties corresponding to the position with smaller stress-strain.
Forged aluminum alloy has better comprehensive properties than cast aluminum alloy, but due to its complex forming process, low yield, and high manufacturing cost, the current manufacturing of aluminum alloy wheels is still mainly based on casting.
Squeeze casting, also known as liquid die forging, is a process method that combines casting and forging characteristics - a certain amount of metal liquid is directly poured into an open metal mold, and a punch is used to apply a certain pressure to the liquid metal, causing it to fill, form, and crystallize and solidify, and generating a certain amount of plastic deformation during the crystallization process. Advantages: Smooth mold filling, metal directly crystallizes and solidifies under pressure, so the casting will not produce casting defects such as pores, shrinkage cavities, and porosity, and the structure is dense. The mechanical properties are higher than those of low pressure casting, and the investment is much lower than that of low pressure casting. Disadvantage: Like traditional forged products, milling is required to complete the shape of the spoke. A considerable portion of automotive aluminum wheels in Japan are produced using extrusion casting technology, with the entire process from pouring molten metal to removing castings controlled by computers, with a very high degree of automation. At present, countries around the world regard squeeze casting as one of the directions for the production of automotive aluminum wheels.
Rolling forming process
Roll forming process is a process in which several rollers rotate to feed materials and form them sequentially to obtain the desired cross-sectional product. In recent years, rolled steel components have accounted for 60% of the new car models developed by mainstream foreign automobile manufacturers, and the rolling threshold has gradually become popular among domestic joint venture brand manufacturers, such as SAIC General Motors, Changan Ford, SAIC Volkswagen, etc. However, this technology has only just started in China's independent brand cars. As the backbone of China's independent brand cars, Zhongtai Automobile proposed to break through technical difficulties and apply it to the latest trial production models in just one year since the end of 2017.
Compared to traditional stamping technology, roll forming technology can not only improve the qualification rate of components, but also effectively improve performance, thereby reducing manufacturing costs.
The rolling forming process can greatly improve the qualification rate of component production, for example, the inner plate of the car threshold beam is generally made of high-strength steel with stronger strength. Under traditional technology, this type of steel has excessive strain in a single section during stamping, which is prone to rebound, and mold debugging is difficult, so the qualification rate is not high. During the rolling production process, the parts can be formed in ten segments. The strain curve obtained through finite element calculation and analysis shows that the peak strain of each segment does not exceed the limit strain of 0.4%, resulting in smaller product rebound and easier control of accuracy.
Die casting process for large car door structural components
Large components of automobiles often play a supporting or load-bearing role, with complex structures, large external dimensions, and uneven thickness. At the same time, it is directly related to the driving safety of cars, so it requires high mechanical performance.
Usually, in order to achieve good performance, heat treatment is required for large components. If reliable connection with other components is required, the workpiece should also have good riveting and welding performance.
The drawbacks of conventional die-casting processes
In the conventional die-casting production process, due to the rapid filling of alloy liquid, it is difficult to exhaust the gas inside the mold cavity and pressure chamber. These gases are drawn into the alloy liquid and will form porosity defects inside the casting. In severe cases, it will cause the casting to lose heat treatment and welding performance. Meanwhile, if some process factors are not effectively controlled, other defects may form in the casting, resulting in poor quality of the workpiece. In response to the above issues, this project combines the characteristics of large automotive components with long-term research experience; A thorough analysis was conducted on the mold design, pouring system, vacuum filling, and process improvement in die-casting production; Reasonably handling these process elements can improve the quality of castings.
Key points of die-casting process
During the mold design process, six key points need to be grasped:
① Reasonably select the pouring position, filling direction of the alloy liquid, and the shape and size of each component to ensure good fluidity of the alloy liquid and establish its sequential solidification.
② Reasonably set exhaust ports at the confluence of alloy liquid and casting corners to minimize the possibility of defects forming in these areas.
③ Check the area of the exhaust duct to ensure smooth exhaust of the cavity.
④ The mold should be able to reliably seal and reduce its impact on vacuum die-casting.
⑤ Reasonably set up cooling and heating devices to accurately control mold temperature.
⑥ Before manufacturing the mold, simulation software can be used to analyze its filling and solidification characteristics; And optimize the mold appropriately based on the simulation results.
The three common pouring methods are shown in Figure 1. Through repeated experiments, it has been found that the pouring method has a significant impact on the plasticity of castings. The conventional top injection method is prone to splashing of alloy liquid, significant air entrainment, and alloy oxidation; At the same time, there is a serious impact between the alloy fluids, which affects the microstructure and quality of the casting and results in poor plasticity. The bottom injection method can effectively reduce the disturbance of the alloy liquid and prevent the occurrence of alloy liquid splashing; The reduction of inclusions and defects in castings significantly improves their plasticity. However, the bottom injection method requires appropriate adjustments to the die-casting machine, requiring specialized pressure chambers and molds; This way, the die-casting machine will lose its versatility and cannot be used in other die-casting situations.
In order to achieve good plasticity of castings, other methods can be adopted. As shown in Figure 1 (c), the top pouring system has been improved. Without special modifications to the die-casting machine to facilitate production conversion, the goal of improving casting plasticity can also be achieved.
In the process of die-casting production, vacuum filling technology is frequently used. Three key points to pay attention to in vacuum technology:
① The vacuum system needs to be started in a timely manner, and vacuum pumping should be carried out immediately when the punch blocks the pouring port.
② The vacuum system needs to have sufficient power to achieve rapid vacuum pumping.
③ Before the pressure chamber is filled, a certain vacuum degree requirement must be met to prevent affecting the casting quality.
Usually, when the absolute pressure inside the casting cavity is greater than 30kPa, it has little effect on the plasticity of the casting.
When its absolute pressure is in the range of 10-15 kPa, the plasticity of the casting changes significantly with the increase of vacuum degree. At the same time, the vacuum degree is directly related to the surface quality of the casting, as shown in Figure 2. The bubbles in the casting gradually decrease with the increase of vacuum degree. However, bubbles do not play a decisive role in the elongation of castings. Meanwhile, high vacuum can increase the selection range of die-casting process parameters. But high vacuum increases the requirements for vacuum equipment, which will increase production costs.
Comprehensive optimization of process
Reasonable selection of injection mode and parameters can help improve the quality of castings. Approximately 30% to 50% of the gas in the die casting comes from the pre filling stage of the alloy liquid inside the pressure chamber; Therefore, it is necessary to set the injection mode of the slow injection stage reasonably to prevent the alloy liquid from forming entrainment inside the pressure chamber as much as possible. And correctly select lubricants and release agents to optimize the spraying process. Accurately control the mold temperature and allocate cooling water to the equipment; Monitor the temperature and flow rate of each cooling circuit to ensure that the mold temperature distribution meets the requirements.
The mold design is reasonable, the die-casting process is appropriate, and the alloy liquid filling mode is ideal, which can reduce the requirement for vacuum degree and obtain high-quality castings. At the same time, for parts with thicker casting walls or larger corners, local pressurization technology can be implemented; Increase casting density and reduce shrinkage and porosity. The alloy liquid front sensor can be used to grasp the flow state of the alloy liquid; Helps optimize filling mode.
Large components of automobiles have high requirements for strength, toughness, etc. It is necessary to accurately grasp the process factors such as mold design, pouring system, and vacuum filling in die-casting production. The prepared castings can be subjected to heat treatment. At the same time, its riveting and welding performance is good, achieving mass and industrial production of large automotive components.
Aluminum alloy for automotive anti-collision beams
Car anti-collision beams are important devices that absorb and alleviate external impact forces during collisions, protect the safety of the vehicle body and passengers. While ensuring the safety and comfort of car collisions, they can effectively reduce the weight of the car and control costs, becoming a hot topic. By optimizing the alloy composition, heat treatment process, and structure, the weight of the vehicle body can be reduced while meeting its safety performance requirements. Additionally, aluminum alloy collision beams have better energy absorption performance than steel collision beams.
Extrusion is a typical method for manufacturing anti-collision beams, which can also be processed by bending and folding plates. The profiles are mostly extruded with alloys such as 6063, 7021, 7029, and 9129. Wan Yinhui et al. used finite element analysis software LS-DYNA to analyze the collision performance of 6061 aluminum alloy anti-collision beam. The results showed that under the same collision test conditions, the aluminum alloy beam had better energy absorption compared to the steel anti-collision beam, and could maintain high energy absorption performance over a large speed range. Yang Yichuan et al. used finite element method to analyze the impact of stamping process on the performance of automotive anti-collision beams, and optimized its stamping process parameters. After process optimization, the rebound and minimum thickness of sheet metal forming were effectively controlled: the severe rebound area at both ends of the anti-collision beam was significantly reduced, and the quality of sheet metal forming was improved, especially the side wall and bottom parts were fully drawn, and the forming quality was significantly improved.
At present, aluminum alloy bumpers in China have just started, and the general crossbeam is aluminum alloy energy absorbing, while the base plate and other components are mostly made of steel. To improve the protective ability of the bumper crossbeam, it is necessary to enhance its ability to absorb energy. The energy absorption ability of the material is proportional to its strength and thickness. However, in the design of car body structures, it is impossible to achieve the goal of improving material energy absorption by infinitely increasing the thickness of steel. Therefore, it is necessary to achieve lightweight, easy disassembly and replacement, and simple maintenance through reasonable material selection, optimization of structural design, and other methods; The manufacturing process should be simple and cost-effective.
Research has shown that properly designed aluminum alloy bumper beams are not only lighter than steel bumper beams, but can also absorb more energy.
Xu Zhongming and Xu et al. optimized the anti-collision beam design through Hyperstudy and LS-DYNA, and the designed beam has an energy absorption effect of 1.9 times that of steel anti-collision aluminum alloy anti-collision beams, with a weight reduction effect of 38.4%. The bumper studied by Feng Yuan et al. consists of two parts: a crossbeam and an energy absorbing bracket. In response to the defect of insufficient longitudinal bending performance of the crossbeam in low-speed collisions, the cross-sectional shape of the bumper was optimized to solve the problem. Car bumpers are important safety protection components in automobiles, and manufacturers often have high requirements for the mechanical properties of bumpers. The mechanical properties of aluminum bumper protection components in automobiles can be improved and improved through heat treatment technology.
In recent years, with the development of aluminum alloy technology, as a new type of aluminum alloy material, foam aluminum alloy is used to manufacture automobile bumpers because of its high ability to absorb impact energy, small density, high temperature resistance, strong fire resistance, easy processing, surface coating treatment and other characteristics. The application of solid foam aluminum alloy in automobile manufacturing is mostly sandwich type plywood. The car bumper made of this material can absorb most of the collision energy generated when two cars collide, thus protecting the safety of the car
Aluminum alloy composite materials for automotive radiators
Aluminum alloy composite material is a collective term for aluminum alloy composite foil, composite strip, and composite plate. It is a key raw material for manufacturing brazed heat exchangers such as automotive air conditioners, radiators, intercoolers, oil coolers, heaters, hand dryers, and air separation equipment. Composite materials are mainly 2-5 layers of composite materials made from 2-3 types of alloys after lamination and compression, with the cladding layer (skin material) mostly being high silicon alloy or low potential alloy. The brazing principle is to place the heat exchanger composed of aluminum alloy composite materials and other pipe fittings and plates into a high-temperature brazing furnace at around 600 ℃, where the cladding layer melts while the substrate does not melt. The high silicon alloy material brazes the radiator fins, heat exchanger channels, and heat exchange fins together through siphon action and diffusion mechanism, thereby achieving heat exchange effect.
Aluminum alloys for automotive insulation
Aluminum alloy engine hood
The application of aluminum alloys on engine covers is also gradually increasing, with Audi Automobile Company being the most successful. Audi's lightweight aluminum body technology is a core technology of Audi, and the company has been conducting research and development in this field for 20 years. Its exquisite application technology is far ahead of other car manufacturers. The Audi A8 and A2 have won multiple awards in competitions with prestigious associations and professional media around the world, and have won over 40 awards to date. Jaguar Japan is also engaged in the development and application of all aluminum body technology, and began selling the top tier sedan XJ with all aluminum body technology in June 2003. In addition, the engine covers of Toyota's new Crown, Mercedes Benz's new E-Class, and Peugeot 307 4P are all made of aluminum alloy material.
Aluminum alloy for oil cooler and air storage tank
Aluminum alloy oil cooler
Almost 100% of the condensers, evaporators, and air handling oil coolers in heat exchangers such as air conditioning equipment (condensers, evaporators), oil coolers, radiators, and heating equipment in automobiles are made of aluminum. The difficulty with aluminum radiators is their durability in heat dissipation, which is mainly due to water leakage caused by corrosion, The reason is internal corrosion caused by coolant and external corrosion caused by salts. Adding rust inhibitors to the cooling water can prevent internal corrosion; Surface treatment and corrosion-resistant alloys can be used to prevent external corrosion caused by salts.