Life is car

I believe that for many prospective car owners, when choosing a vehicle style, they will find that many high-end models use 17 inch wheels; while for low-end models, the wheels used are 16 inches. So how should we choose the 16-inch and 17 inch wheels, and what are their advantages and disadvantages?

Advantages and disadvantages of 16 inch and 17 inch wheels

cost:

Compared with the 17 inch wheel, the 16 inch wheel has a smaller mass and less material, and the corresponding cost and cost will be lower; while the 17 inch wheel has a larger size and is generally equipped on high-end models, so its Prices will be higher.

Fuel consumption:

Generally speaking, the tire width suitable for 16 inch wheels will be narrower, and the tires with narrow tire width will have a smaller contact area with the ground, and the corresponding fuel consumption will be reduced; on the contrary, 17-inch wheels will be equipped with wider treads. tires, and tires with wider treads will have greater rolling resistance, correspondingly, it will also increase the fuel consumption of the vehicle.

Visual look and feel:

The size of the 17-inch wheel is larger, which can better highlight the temperament of the vehicle; while the size of the 6-inch wheel is smaller, and its overall visual appearance will be slightly stingy.

Maneuverability:

Since the tires fitted with 16 inch wheels have a narrower tire width and a higher flat ratio, their handling will also be weakened accordingly; while the tires fitted with 17 inch wheels are correspondingly wider than 16-inch tires and have a higher flat ratio. Lower, so its ability to feedback road information and deal with roll is stronger, all in all, the handling is better.

Whether 19 inch wheels are better or 17 inch wheels is better depends on the situation. Big wheels and thin tires are indeed more beautiful, and the bumps on smooth roads are weak, fuel consumption is low, and the handling is strong; but thin tires with large wheels are in mud pits, or in road conditions with more stones and steel plates, thin tires Tires are prone to blowouts and will drive more bumpy than smaller wheels. 17 inch wheels will be cheaper and cheaper than 19 inch wheels

In general, 19 inch wheels have better visuals and handling performance than 17 inch wheels, and 17 inch wheels are more comfortable and economical than 19 inch wheels.

Are bigger wheels better?

The larger the rim, the flatter the tire, the less resilient it is overall, and the harder it is to digest and filter vehicle vibrations on uneven surfaces, which means the thinner the tire, the more likely it is to bulge and blow out. As a result, the feedback of the suspension system to the road conditions will be dull, the moment of inertia will be greater, the rolling resistance will increase, so will the fuel consumption, and there will be a dry bombing accelerator not working.

Therefore, the bigger the hub is not the better, the overall performance of the car should be pursued, to achieve a uniform synthesis, and to clarify its own focus. SUV models have thicker tire walls and larger wheel hubs, while sports car performance cars have thinner tire walls and smaller wheel-hub ratios. Generally, small cars have particularly small wheels and relatively thick tire walls.

Factory-fitted wheels are looking for the best balance of economy and comfort. The reason high-performance vehicles have large wheels is to be able to install larger brake discs to improve braking performance. After all, a performance vehicle with hundreds of horsepower is very dangerous without adequate braking power, and performance vehicles don’t put comfort first. Therefore, even if the big wheels are beautiful and high-end, don’t blindly modify them.

We know that the wheel size of each model is different. The low-end model is the smallest, the high-end model is the largest, and some models do not have this rule, but most of them are incremental. For example, the diameter of the low-end model is 17 inch alloy wheels, and the middle model It may be 18 inches, and the high profile may be 19 inch alloy wheels. Different sizes of tires have different effects. So what’s the difference between a big wheel and a small wheel?

First of all, from the appearance, it will be found that the body with large wheels will look more atmospheric and sporty, especially for some cars. And the larger the wheel hub, the higher the stability of driving, especially when driving at high speed, the driver will feel that the body is very stable in the car, and there will be no feeling of floating.

But big wheels also have their downsides. Although the driving is more stable, the tire noise of the car will also become very large at the same time, especially when driving on high-speed roads, the tire noise will become especially obvious. Feelings can get really bad.

Smaller size tires are generally used in family cars. Because the owners of family cars are the same, the car can be more fuel-efficient, and the small car tires can better release the power, thereby reducing the fuel consumption of the car, and for some owners who pursue comfort and quietness, the tire noise is naturally better than Cars with big wheels are smaller. Of course, small wheels also have some disadvantages, that is, the braking performance is relatively poor, and the stability of the tires is not as good as that of large tires. Therefore, when braking under extreme conditions, the safety of small wheels is far less than that of large wheels.

For car upgrades, one of the first and easiest ways to think of is to change the hub, but what effect will the replacement of the hub have on the speed increase and overall performance of the vehicle?

You may often see some Volkswagen Golfs and Audi A4s with more ground clearance than normal, and the wheels they are fitted with look a lot larger than normal. To be honest, since the original wheels that most manufacturers give cars as standard are really flat, in order to improve the overall visual impact of the car body, many enthusiasts are very keen to replace large-sized wheels to make them look better. Aggressive, which is completely understandable. However, does the replacement of the big wheels affect the original performance of the car? Is there a certain degree of improvement in acceleration performance from 0-60 mph in particular?

First, let’s briefly understand the fundamentals of wheel dynamics. To make the wheel turn, a torque is needed to drive the axle, and we can calculate the corresponding torque using the radius of the wheel and the tangential force of the wheel.

If the torque value is treated as a constant (assuming a steady torque from the car engine), then the wheel radius changes and the driving force from the wheels changes accordingly.
Let’s take the 1.6-litre Volkswagen Goft GTI fitted with 15 inch wheels as an example, which produces a maximum torque output of 350 Nm. Assuming an even distribution between the two wheels (175 Nm each) and disregarding the effect of transmission efficiency, all power goes to the wheels, the calculated driving force is around 460N. When the wheel diameter is increased to 19 inches, the driving force is reduced to 360 N. According to Newton’s second law, the force acting on an object is equal to its mass times its acceleration. Therefore, increasing the wheel size will reduce the driving force transmitted to the wheels, ultimately resulting in a reduction in the car’s acceleration. The above assumes that all other components such as engine, driveshafts, gears and differentials are still using original parts designed for the original factory standard wheel size.

To achieve the same acceleration with increased wheel size, the engine has to work harder to turn the wheels, so fuel economy is bound to suffer.

Car and Driver magazine once ran an interesting test to prove how much wheel size affects the acceleration of a Volkswagen Golf. The car was tested for 0-60 mph times with different wheel sizes, and with 15 inch wheels, it took just 7.6 seconds. When the wheels are increased to 19 inch wheels, the acceleration time increases to 7.9 seconds. Tests from 0-100 mph yielded the same results, establishing that larger wheels would reduce the car’s acceleration performance.

Since the speedometer and gearing of the car are designed according to the standard tire diameter, the wheel size is increased, the thickness of the tire must be reduced to maintain the same overall diameter, and the car can be exempted from re-tuning. This also means that the sidewall of the tire must be stronger to withstand the lateral forces of production during cornering, so the application of flat tires reduces driving comfort.

Also, increasing the diameter of the wheel hub usually increases the width, which increases the contact surface between the tire and the road to improve grip, but the increase in friction makes it harder for the car to drive through corners and the body rolls The degree will be greatly increased, so it is necessary to strengthen the suspension to maintain the stability of the car.

Also, the handling of the car will vary with wheel size, smaller diameter hubs will allow for cleaner handling as the wheel covers less distance per revolution, while larger, wider (heavier) The wheels have the potential to cause understeer, making maneuvering difficult.

So, do you want to pursue „beauty” or „performance” when it comes to replacing large-sized wheels?

In recent years, the growth rate of forged wheels is faster than that of cast wheels. Although the production cost of the former is higher than that of casting, the former has a higher performance price. At present, the forming of forged wheel hubs at home and abroad can be mainly divided into the following categories:

1. Casting and forging method

It is a method of using a casting as a blank in a forging process and plastically processing it. Because forging is the final forming process of the part. Thus casting defects can be eliminated. Improving the microstructure of the product greatly improves the mechanical properties of the product compared to castings. At the same time, the advantages of the casting process in forming complex parts are fully utilized, so that the forging process of products with complex shapes can reduce the utilization rate of materials and greatly improve the production cost.

The performance of aluminum wheels produced by casting and forging technology can fully meet the mechanical properties of forgings, but the production cost can be reduced by 30% compared with ordinary forgings. At present, the process has been adopted by many Japanese companies since it was successfully applied to mass production in September 1996, and the economic effect is good. Although there is some research and application in the casting and forging process in China, there is no report that it is applied to the production of aluminum alloy wheels.China wheels

Classification and characteristics of aluminum alloy wheels

2. Semi-solid die forging

The so-called semi-solid die forging is a process in which the semi-solid billet is heated to a semi-solid state with about 50% of the volume liquid phase, and then it is formed by one-time die forging to obtain the required close-sized finished parts. This is a new process between solid-state forming and liquid-forming. Semi-solid die forging has many unique advantages. The shrinkage of the parts in the mold is small, it is easy to form near finalization, and the amount of machining is reduced. Microporosity is much less than in conventional castings, forming temperatures are low, and mold life is long.

3. Conventional forging method

Forging is one of the earlier forming processes for aluminum wheel applications. Forged aluminum wheels have the advantages of strength, good corrosion resistance, accurate size, and small processing volume. In general, its weight is only equivalent to 1/2 or less of the same size steel wheel, and the grain flow direction of the forged aluminum wheel is consistent with the direction of the force. Its strength, toughness and fatigue strength are significantly better than those of cast aluminum wheels.

At the same time, the performance is very reproducible. Almost every wheel has the same mechanical properties. The typical elongation of forged aluminum wheel is 12%~17%, so it can absorb the vibration and stress of the road very well. Cast wheels are generally quite capable of withstanding compressive forces, but are far less capable of withstanding shock-shear and tensile loads than forged alloy wheels.

1. Contractility

Shrinkage is one of the main characteristics of cast aluminum alloys. Generally speaking, the alloy is divided into three stages from liquid pouring to solidification and cooling to room temperature, namely liquid shrinkage, solidification shrinkage and solid state shrinkage. The shrinkage of the alloy has a decisive influence on the quality of the casting, it affects the size of the shrinkage cavity, the generation of stress, the formation of cracks and the change of the size of the casting. Usually casting shrinkage is divided into volume shrinkage and linear shrinkage. In actual production, linear shrinkage is generally used to measure the shrinkage of the alloy.

　　The shrinkage of aluminum alloy is usually expressed as a percentage, which is called the shrinkage rate.

　　 (1) Body contraction Body contraction includes liquid contraction and solidification contraction.

　　 From pouring to solidification, macroscopic or microscopic shrinkage occurs in the final solidification of the casting alloy liquid. This kind of macroscopic shrinkage caused by shrinkage is visible to the naked eye, and is divided into concentrated shrinkage and dispersive shrinkage. The pores of the concentrated shrinkage holes are large and concentrated, and are distributed on the top of the casting or at the hot section with a thick section. The dispersive shrinkage cavities are scattered and fine, most of which are distributed in the casting axis and hot joints. The microscopic shrinkage cavities are difficult to see with the naked eye, and most of the microscopic shrinkage cavities are distributed under the grain boundary or between the dendrites of the dendrites.

　　 Shrinkage cavity and porosity are one of the main defects of castings. The reason is that the liquid shrinkage is greater than the solid shrinkage. It is found in production that the smaller the solidification range of cast aluminum alloys, the easier it is to form concentrated shrinkage cavities, and the wider the solidification range, the easier it is to form dispersive shrinkage cavities. Therefore, the casting aluminum alloy must conform to the principle of sequential solidification in the design, that is, the casting is in The body shrinkage from liquid to solidification should be supplemented by the alloy liquid, and shrinkage cavities and looseness are concentrated in the outer riser of the casting. For aluminum alloy castings that are prone to looseness, the number of risers is more than that of concentrated shrinkage holes, and chilled iron is set at the places that are prone to looseness, and the local cooling rate is increased to make it solidify at the same time or quickly.

　　 (2) The shrinkage of the line shrinkage will directly affect the quality of the casting. The greater the linear shrinkage, the greater the tendency of aluminum castings to produce cracks and stress; the greater the size and shape of the castings will change after cooling.

　　 Different casting aluminum alloys have different casting shrinkage rates. Even if the same alloy has different castings, the shrinkage rates are different. On the same casting, the shrinkage rates of length, width, and height are also different. It should be determined according to the specific situation.

　2. Casting stress

　　 Casting stress includes thermal stress, phase transformation stress and shrinkage stress. The causes of various stresses are not the same.

　　 (1) Thermal stress Thermal stress is caused by uneven thickness and inconsistent cooling at the intersection of different geometric shapes of castings. Compressive stress is formed at the thin wall, resulting in residual stress in the casting.

　　 (2) Phase transformation stress The phase transformation stress is due to the phase transformation of some cast aluminum alloys during the cooling process after solidification, which brings about the volume and size changes. It is mainly caused by uneven wall thickness of aluminum castings and phase changes in different parts at different times.

　　(3) Shrinkage stress Aluminum castings are hindered by the mold and core when they shrink, resulting in tensile stress. This kind of stress is temporary, and aluminum castings will disappear automatically when they are out of the box. However, improper unpacking time often causes hot cracks, especially for metal cast aluminum alloys that are prone to hot cracks under such stress.

　　The residual stress in the cast aluminum alloy reduces the mechanical properties of the alloy and affects the machining accuracy of the casting. Residual stress in aluminum castings can be eliminated by annealing. The alloy has good thermal conductivity and no phase change during the cooling process. As long as the casting structure is designed reasonably, the residual stress of the aluminum casting is generally small.

　3. Inhalation

　　 Aluminum alloy is easy to absorb gas, which is the main characteristic of cast aluminum alloy. The hydrogen produced by the reaction between the components of liquid aluminum and aluminum alloys and the moisture contained in the furnace charge, organic matter combustion products, and molds is absorbed by the aluminum liquid.

　　 The higher the temperature of the aluminum alloy melt, the more hydrogen is absorbed; at 700°C, the solubility of hydrogen in 100g of aluminum is 0.5 to 0.9, and when the temperature rises to 850°C, the solubility of hydrogen increases by 2 to 3 times. When alkali metal impurities are contained, the solubility of hydrogen in molten aluminum is significantly increased.

In addition to the inhalation of cast aluminum alloy during smelting, it will also produce inhalation when pouring into the mold. The liquid metal entering the mold decreases with the temperature, the solubility of the gas decreases, and excess gas is precipitated, and there is a part of the gas that cannot be escaped. It is left in the casting to form pores, which are usually called „pinholes”. The gas sometimes combines with the shrinkage cavity, and the gas precipitated in the molten aluminum stays in the shrinkage cavity. If the pressure generated by the heating of the bubbles is large, the surface of the pores is smooth and there is a bright layer around the holes; if the pressure generated by the bubbles is small, the inner surface of the pores is wrinkled, which looks like „fly feet”, and there are shrinkage holes on closer inspection. Characteristics.

　　The higher the hydrogen content in the cast aluminum alloy liquid, the more pinholes are produced in the casting. Pinholes in aluminum castings not only reduce the air tightness and corrosion resistance of the castings, but also reduce the mechanical properties of the alloy. To obtain aluminum castings with no or less pores, the key lies in the melting conditions. If a covering agent is added for protection during smelting, the amount of gas inhalation of the alloy is greatly reduced. Refining the molten aluminum can effectively control the hydrogen content in the molten aluminum.

4. Liquidity 　　 Fluidity refers to the ability of alloy liquid to fill the mold. The fluidity determines whether the alloy can cast complex castings. Eutectic alloys have better fluidity among aluminum alloys.

There are many factors that affect fluidity, mainly the composition, temperature, and solid particles of metal oxides, metal compounds and other pollutants in the alloy liquid, but the fundamental external factors are the pouring temperature and pouring pressure (commonly known as pouring head) The heights.

In actual production, when the alloy has been determined, in addition to strengthening the smelting process (refining and slag removal), it is also necessary to improve the mold processability (sand mold air permeability, metal mold exhaust and temperature), and do not affect Under the premise of casting quality, increase the pouring temperature to ensure the fluidity of the alloy.

5. Hot cracking 　　The occurrence of hot cracks in aluminum castings is mainly due to the shrinkage stress of the castings exceeding the bonding force between the metal grains. Most of them occur along the grain boundaries. It can be seen from the crack fracture that the metal at the cracks is often oxidized and loses its metallic luster. The cracks extend along the grain boundary, with a zigzag shape, a wide surface and a narrow inside, and some penetrate the entire end surface of the casting.

Different aluminum alloy castings have different tendency to crack. This is because the greater the difference between the temperature at which a complete crystalline framework is formed during the solidification of the cast aluminum alloy and the solidification temperature, the greater the shrinkage rate of the alloy and the greater the tendency to produce hot cracks. , Even the same alloy has different hot cracking tendency due to the resistance of the mold, the structure of the casting, the pouring process and other factors. Measures such as regressive casting molds or improved casting aluminum alloy casting systems are often used in production to avoid cracks in aluminum castings. The hot crack ring method is usually used to detect hot cracks in aluminum castings.

6. Air tightness

The airtightness of cast aluminum alloy refers to the degree of non-leakage of cavity-type aluminum castings under the action of high-pressure gas or liquid. Airtightness actually characterizes the degree of compactness and purity of the internal structure of the casting.

　　The airtightness of cast aluminum alloy is related to the properties of the alloy. The smaller the solidification range of the alloy, the smaller the tendency for porosity. At the same time, the smaller the precipitation pores, the higher the airtightness of the alloy. The airtightness of the same cast aluminum alloy is also related to the casting process. For example, lowering the casting temperature of the cast aluminum alloy, placing cold iron to accelerate the cooling rate, and solidifying and crystallization under pressure, etc., can all make the airtightness of aluminum castings. improve. The impregnation method can also be used to plug the leakage gap to improve the air tightness of the casting.The copyright belongs to the author Website of China wheels .

The low-pressure wheel hub is named after the casting process. This process is suitable for mass production. Because of the high success rate of the finished product, most automobile manufacturers specify this process.

Wheel hub, English name: Car Rim, a cylindrical metal part used to support the tire with the shaft as the center in the automobile tire. In layman’s terms, it is the part where the axle is installed in the center of the wheel and is connected to the brake drum (brake disc) and the wheel disc. And important parts of the axle shaft.

When many car users upgrade their tires, they often ignore the importance they attach to the wheels. If you compare a car to a person, the tires are shoes and the wheels are feet. Wheel hubs are also called rims, and Guangdong, Hong Kong and Taiwan regions are called car bells. The most commonly used method to upgrade car wheels is to use aluminum alloy wheels, or to use larger wheels to improve car performance and appearance.

According to different manufacturing methods, wheels are mainly divided into two categories: Casting and Forged. Casting is divided into two types: Gravity Casting and Low Pressure Casting. Forged wheels can be divided into two types: one-piece forged wheels and multi-piece forged wheels.

1. Gravity casting

Gravity casting is to pour the liquid alloy into the mold to cool and form. Due to the simple manufacturing process and the durable mold, it has become the lowest cost manufacturing method. But the quality is not very good, because each part of the wheel hub is not necessarily evenly distributed, the molecular pores inside the metal are larger, and the strength is also reduced a lot.

2. Low pressure casting

Low-pressure casting is to press the liquid alloy into the mold with a smaller pressure, so that the distribution of molecules is even, there are fewer sand holes, and the shape can be more complicated and delicate. To ensure the density of the liquid metal, but also to ensure the strength of the metal after solidification. The low-pressure casting process is all completed by machinery, and the yield rate of casting molding is high, which is very suitable for mass production. At present, the cast aluminum alloy wheels designated by automobile manufacturers are all produced by this process.

Low-pressure hub

3. One-piece forging

One-piece wheel hub means that the entire wheel hub is a whole. Forging can be divided into two processes, forming forging (die forging) and milling forging. Forming forging means that after forging, the shape of the wheel has been basically formed. Milling and forging means buying ready-made forged wheels. The blank is then milled through a CNC machining center to form the shape of the wheel. The one-piece wheel hub is light in weight and can be the lightest, with good dynamic balance, good reliability, and no hidden danger of air leakage, but the shape is relatively simple.

4. Multi-piece forging

The multi-piece forged wheel is composed of two parts: the rim and the spoke. The rim part of the three-piece forged wheel hub consists of two parts: the front piece and the back piece, so the three-piece wheel hub is composed of three parts: the front piece, the rear piece and the spokes. The multi-piece rim part can be shared, so the shape can only be replaced by the middle plate, which can match the spokes and rims of different sizes, so there are more shapes. But the weight is heavier, the dynamic balance is not as good as one piece, and the assembly requirements are also higher.The copyright belongs to the author Website of China wheels www.jihoowheels.com .

In fact, the difference between these two names lies in the casting process. From a purely literal point of view, one uses a low-pressure casting process and the other uses a spinning casting process. Does the quality indicate the difference between the two?
Low-pressure hub

The low-pressure wheel hub is named after the casting process. This process is suitable for mass production. Because of the high success rate of the finished product, most automobile manufacturers specify this process.

Low-pressure casting is to press the liquid alloy into the mold with a smaller pressure, so that the distribution of molecules is even, there are fewer sand holes, and the shape can be more complicated and delicate. To ensure the density of the liquid metal, but also to ensure the strength of the metal after solidification.
The low-pressure casting process is all completed by machinery, and the yield rate of casting molding is high, which is very suitable for mass production. At present, the cast aluminum alloy wheels designated by automobile manufacturers are all produced by this process.
Spinning hub

Spinning casting is a key technology in the manufacturing process of the wheel hub, and before explaining the spinning casting process, let’s talk about the manufacturing process of the wheel hub. Nowadays, aluminum alloy wheels have gradually become standard products for automobiles, and only some low-end and low-end models are still using steel wheels. In the production process of aluminum alloy wheels, the metal material is first heated to a liquid state, and then extremely high-temperature liquid metal is poured into different casting molds, through „low pressure casting”, „gravity casting” and then through polishing, polishing and other finishing processes. Make the final product.

Everyone will encounter more or less questions about cars. Recently, the editor was asked by netizens: What is the difference between 18 inch wheels and 19 inch wheels? I believe many people don’t know about this question, so I will simply give you the following Let’s talk about it, I hope it will be helpful to everyone.
The difference between 18-inch wheels and 19-inch wheels is mainly reflected in the size, manufacturing cost, price, driving comfort and fuel consumption, as detailed below:

1. The size of the external dimensions refers to inches, and 1 inch is equal to 2.54 cm. 18 inch refers to the diameter of the hub circle is 45.72 cm, slightly smaller than the 19 inch alloy wheels.
2. Manufacturing cost Because of the different components of materials, the manufacturing cost of 19 inch wheels is much higher than that of 18 inch alloy wheels.
3. Price Generally speaking, the larger the size, the higher the price of the same type wheel hub.
4. Driving comfort The larger the wheel hub and the thinner the tire wall, the more realistic the road surface feedback will be when the car is driving. Owners and friends who pay attention to handling and appearance can choose 19 inch wheels. The tires with small wheels and thick sidewalls can effectively filter road vibrations, and 18 inch wheels are better in terms of comfort.
5. Fuel consumption The larger the wheel hub and the wider the tread, the greater the friction with the ground, so the higher the fuel consumption. The same car with 19 inch wheels will consume more fuel than 18 inch wheels.
   The editor believes that if the original 18 inch wheels are not recommended for family cars, it is not recommended to replace them with 19-inch alloy wheels. If your car has steel wheels or iron wheels, you can replace them with aluminum alloy wheels of the same size.

The spinning manufacturing process is a combination of low pressure casting and hot spinning forming technology to achieve the goal of „quality close to forged alloy wheels and cost close to cast alloy wheels”. As the name suggests, spinning is a branch of casting. It performs casting on the rim part on the basis of casting. Rotary stamping, thereby changing the internal structure of the metal at the rim, so that the internal molecules are arranged in a fibrous shape with a higher density.

Spinning alloy wheel casting steps

  Compared with ordinary casting spinning technology, it has higher mechanical performance. The main performance is: higher strength and higher toughness. In addition, the spinning rim has a thinner section and the overall weight of the rim is also reduced.

  The first step: the blank part preheated by the induction furnace is fixed on a large-scale high-speed spinning equipment, after the blank part is matched with the special inner cylinder mold, the spinning forming starts.

  The second step: the large-scale high-speed spinning equipment starts to rotate at high speed, and the secondary heating equipment is started to keep the spinning rim part at a constant temperature, and at the same time, the high-pressure wheel rotation is started to make it powerfully squeeze under the double pressure of the special mold matched with the special inner cylinder. Press the rim to stretch the rim part of the blank to create a preliminary rim shape.

  The third step: the advantages of tensile strength and yield strength keep high-speed rotation and high temperature protection molecules from being strained, repeated high-pressure rotation to stretch the rim to create a high-strength thin wall of the rim and reach the pre-designed size specifications

  Step 4: Adjust the speed from top to bottom to fine-mold the thin wall of the rim. The whole process of shaping the rim is to improve the crystal structure of the aluminum alloy to be tighter, the molecular structure is more refined and the fiber is present, and the elongation of the material is effectively improved.

Comparison of spinning alloy wheels before and after

  During the spinning process, the double spinning wheel makes the rim of the blank become thinner and longer, and the internal metal structure is changed to improve strength and light weight.