Foreword...
Let me start with the fact that pure aluminum is extremely rare in the automotive industry, most often these are alloys with the addition of various additives that improve the properties of this metal. For example, the aluminum car body or its individual parts are made from aluminum, in which magnesium, silicon or manganese is added. Such additives make it possible to obtain a more durable, but at the same time the same light and ductile metal.
Aluminum parts are produced in various ways, depending on its purpose. The most common production methods are forging, casting, stamping, and extrusion. The most popular form of manufacturing aluminum parts is, of course, casting. Using this method, engine parts, various hulls, as well as some suspension parts are cast.
The pioneer in the "aluminum direction" was the company "Audi", which in 1994 launched mass production of the Audi A8, in which the body was completely made of aluminum. In those days, this decision was revolutionary and shook up the world of the automotive industry. The weight of the aluminum A8 was only 231 kg. Impressive, isn't it?
What is more expensive aluminum or stainless steel
So the heating season ended with grief in half, after which the issue of changing batteries came to the fore. It's time to send the leaky ancient cast-iron radiators to a well-deserved rest, putting something more modern in their place.
Private developers, when installing heating, also often cannot decide on the type of radiators. Having heard enough sellers in stores touting the most popular models, an ignorant buyer is at a loss.
And which radiators are better - aluminum or bimetallic, he still does not represent. Perhaps we can look at this question objectively?
The fins located on the inside can significantly increase the heat transfer area up to 0.5 square meters. Radiators are made in two ways.
The extrusion method gives cheap and light products of not the highest quality (in Europe this method is not used). More expensive, but more durable will be radiators made by casting.
One of the types of aluminum radiators.
2. Bimetal radiators are made from two different metals. The body, equipped with ribs, is made of aluminum alloy. Inside this housing there is a core of pipes through which the coolant flows (hot water from the heating system). These pipes are made either from steel or from copper (and the latter are practically not found in our country). Their diameter is smaller than that of aluminum models, so there is a greater likelihood of clogging.
The appearance of the bimetallic radiator is very aesthetic, and the design satisfies the most sophisticated requests. All of its steel components are hidden inside.
Aluminum and aluminum alloys
Aluminum products include products and semi-finished products from unalloyed aluminum and aluminum alloys, wrought and cast, as well as raw materials for their production - primary and secondary aluminum in the form of liquid aluminum, ingots, billets, etc.
Unalloyed aluminum - aluminum without alloying elements, in which the aluminum content is at least 99.00%.
Aluminum alloy - aluminum that contains alloying elements, moreover, the aluminum content is greater by weight than any of the other elements in the alloy, and the aluminum content is at least 99.00%.
Alloying element - a metallic or non-metallic element that is controlled within the upper and lower limits in order to give the aluminum alloy some special properties.
Impurity - a metallic or non-metallic element present in the metal, the minimum content of which is not controlled.
Best Answers
Dm:
Technology. Aluminum does not occur in its pure form in nature. Only in minerals. Isolate by electrolysis. “The modern method of obtaining was developed independently by the American Charles Hall and the Frenchman Paul Héroux. It consists in the dissolution of aluminum oxide Al2O3 in a melt of Na3AlF6 cryolite, followed by electrolysis using graphite electrodes. This method of obtaining requires large amounts of electricity, and therefore was in demand only in the 20th century. For the production of 1 ton of aluminum, 1.9 tons of alumina and 18 thousand kWh of electricity are required. “In the past, pure aluminum was considered a precious metal.
Alexey Olegovich Pavlenko:
There is more demand for it. Non-ferrous metal, however!
Anna Kiseleva:
maybe because it still melts better, the melting point is not so high, and it’s convenient and lighter though
Roma:
iron is black metal and aluminum is non-ferrous metal
Old man Mochenkin grandfather Ivan:
Because it does not occur in its pure form.
gavrilov hammer:
electrical conductivity
Roman Karpin:
Aluminum is a non-ferrous metal and therefore more expensive. It also melts easier and is softer.
Alexander Radchenko:
The extraction technology is very labor intensive. Obtaining aluminum from alumina is a much more complicated process than smelting steel from ore.
Valek Dark:
In addition to higher energy and resource costs for obtaining aluminum, it also has very popular properties in all industries - lightness, corrosion resistance, ductility, thermal and electrical conductivity, environmental friendliness, etc. When it was discovered, it was used in jewelry and was valued more than gold.
Kirill Gribkov:
why is gasoline the most expensive fuel? the answer is just right for you
Roma )))Elektrik ((( Tsirkunov:
The cost of smelting a ton of aluminum is more than iron!
Among the advantages of an aluminum body, the following points can be distinguished
1. Excellent weight-to-strength ratio. Aluminum is 60% lighter than steel for equal dimensions and volumes. Thanks to this, body parts are lighter, hence less weight and significant fuel savings, and of course, less harmful emissions into the atmosphere.
2. Aluminum does not corrode. This property has a very positive effect on the duration of the "life" of the body and the car itself. However, one should not assume that aluminum does not age or rot at all; under certain circumstances and conditions, aluminum is also capable of oxidizing and breaking down.
3. Aluminum parts are highly recyclable. The ease of remelting makes this metal very beneficial for car manufacturers, as it allows it to be used several times, and the production process itself is greatly simplified.
4. Energy absorption. Compared to steel, aluminum absorbs and dampens vibrations much better, this also applies to strong shocks, which aluminum parts absorb 50% better, preventing them from spreading further. This factor is very important for those who value their own safety, as well as the safety of their passengers.
5. Strength and resistance to torsion loads. The aluminum body, however strange it may sound, is more rigid in terms of twisting, this gives the car stability, and also allows you to perform more “sharp” maneuvers.
6. Low undercarriage load and unsprung masses. Like it or not, the difference in weight has a positive effect on the wear of tires, chassis parts, and also makes the car smoother while driving.
7. Fuel consumption. As I said, less mass of an object is always less effort to move it. Therefore, an aluminum body can cause abnormally low fuel consumption.
It would seem that there are so many "pluses" that there are simply no "minuses" ... But - no, as they say, a coin always has two sides.
Recycled aluminum
New (technological) and old (used) aluminum scrap is the initial charge for the production of secondary aluminum. So-called "secondary smelters" mix old scrap or process aluminum scrap and produce so-called secondary aluminum alloys. These alloys are supplied to foundries as ingots for remelting or as liquid metal. These foundries produce aluminum products in the form of castings, which are widely used, for example, in the automotive industry. Secondary aluminum is also used for the manufacture of ingots, bars and pellets for steel deoxidation.
Sorted aluminum scrap, which consists of wrought alloys, can again be used in enterprises for the production of "semi-finished" aluminum products - semi-finished products. An example of this is aluminum cans for beer and soft drinks, which are very widely recycled around the world.
Scrap aluminum cans
Aluminized steel - Wikiwand
Aluminized steel - steel that has been hot dip coated on both sides with a silicon aluminum alloy. This process ensures that the tight metallurgical bond between the steel sheet and its aluminum coating, producing a material with a unique combination of properties, does not possess either steel or aluminum alone.
Aluminized steel shows better behavior against corrosion and keeps the properties of base material steel for temperatures lower than.
For example, it is commonly used for heat exchangers in residential ovens, commercial HVAC unit rooftops, car air conditioners, ovens, kitchen ranges, water heaters, fireplaces, barbecue burners and pie pans.
Features are determined by the exact metals used as well as the process used.
Types
Type 1: hot dip coated with a thin layer of aluminium/silicon alloy containing 5% to 11% silicon to promote better adherence. It is intended principally for thermal resistance applications and also for use where corrosion resistance and heat are involved.
Possible finish uses are muffins, stoves, ovens, ranges, heaters, water heaters, fireplaces and cake pans. Aluminized steel cannot resist with almost no change in base material. But due to the silicon content it develops a black spot.
Aluminized steel has slowly begun to transform bakery trays that were previously made with galvanized or galvalume steel as it does not contain lead, which is toxic. Type 1 is also commonly found in industrial products.
Type 2: Hot drop coated with commercially pure aluminium. It is intended principally for applications requiring atmospheric corrosion resistance. Type 2 may eventually be produced into corrugated roofing and siding, grain bins, drying ovens and air conditioner condenser housings.
Properties
The basic structure of aluminized steel is a thin aluminum oxide layer on the outside, then an intermetallic layer, which is a combination of aluminum, silicon, and steel, and finally a steel core.
Both Type 1 and Type 2 exhibit excellent high reflectivity features. At temperatures up to aluminized steel reflects up to 80% of the heat projected onto it. Aluminized steel has the ability to maintain its strength at temperatures up to . Although stainless steel is the stronger of the two, aluminized steel has a larger electrostatic surface and can therefore repel heat better.
Aluminized steel is very resistant to corrosion due to the thin layers of aluminum and silicon that keep the base steel from oxidizing.
However, despite the good corrosion resistance of aluminized steel, if the aluminum layer is destroyed and the steel is exposed, then the steel can oxidize and corrosion can occur.
Consumption
In North America, almost 700,000 tons of aluminized steel are consumed annually. Some common products made from aluminized steel include water heaters, ranges, stoves, space heaters and grills.
Treatment
Aluminized steel can be made using a variety of processes, sheathing, hot dip, electroplating, plating and aluminizing, but the most efficient process is hot dip. The hot dip process starts by cleaning the steel, then placing the steel in an Al-11%si bath at a temperature of 988K and shaken, then pulled out and air dried.
The aluminum expands into the steel, creating an intermetallic layer above the steel base layer, but below the outer aluminum coating. The aluminum coating is oxidized to help protect the internal steel from corrosion and further aluminum propagation. Silicon is added to the aluminum bath to create a thinner layer of aluminum on the steel.
The hot dip process is cheaper and more efficient to produce aluminized steel than any other process.
Usage
Aluminized steel has been developed to provide greater structural durability and high output strength in highly corrosive environments.
Aluminized steel maintains the strength of high alloy steel, but at a fraction of the cost.
Aluminized steel is cheaper to manufacture than high alloy steels and thus is the material of choice for automobile and motorcycle exhaust manufacturing systems.
Of the minuses, the following can be distinguished
1. The complexity of production. Aluminum parts require technologically sophisticated fastening methods (riveting, laser welding, bolted connections), in addition, they all require expensive equipment and materials.
2. Expensive and problematic repairs. Welding of aluminum parts provides for the presence of either a laser or argon welding. The welder himself must have extensive welding experience, since the outcome of the entire repair and the possibility or impossibility of further use of the aluminum part depend on this. In addition to other troubles, such work will cost several times more than similar work, but using conventional welding and steel.
3. Price. The high cost of aluminum compared to conventional steel in one way or another affects the final cost of the product. A car with an all-aluminum body can cost one and a half to two times more than a similar car with an all-metal frame.
4. Configuration and forms of parts. The manufacture of an all-aluminum body imposes certain responsibilities on the manufacturer. For example, to give strength to parts, they have to be reinforced with additional stiffeners or made more voluminous, as a result, the design may not be as compact and attractive as we would like.
As an example and proof, I propose to pay attention to two bicycles - completely aluminum and completely steel. Frames will differ not only in weight, but also in the diameter of the tubes used in their production.
5. Good noise conductivity. In this case, the word "good" is a disadvantage, I think you understand what I mean? The better the metal conducts noise, the more it will be in the cabin of an aluminum car, I think it's clearer? This feature requires additional layers of sound insulation, which increases the weight of the car, and also costs a lot of money.As a result, such a car will either receive a good “shumka” on the conveyor and at the same time turn out to be more expensive, or it will be delivered “as is”, and all the costs of soundproofing will fall on your shoulders, and, admittedly, will pull a lot of money.
6. Maintainability. It is difficult to repair an aluminum body, and there are not so many people willing or, more simply, capable of doing it, the reason is that an aluminum body is difficult to repair! After impact or deformation, aluminum parts and structures are very difficult to restore, since the structure of the metal is broken. For this reason, the repair of such parts or structures is often simply impossible or simply unprofitable, and ends with a complete replacement.
As you can see, such, at first glance, ideal and impeccable material has many shortcomings that ordinary people do not even suspect. Probably, it is for this reason that most of them so zealously defend their point of view, proving that an aluminum body is a real good and a solid “plus”. Well, as they say, to each his own, I hope after reading this material you will not be one of these “experts” and before you buy a car with an aluminum body, weigh all the positive and negative aspects of this difficult material.
Text: AutoPulsar.
How to choose a car muffler
A car muffler is either the entire exhaust system as a whole, or just the rear part of it. This article focuses specifically on the rear of the exhaust system. Of course, there are cars where the main muffler is located in the center of the exhaust tract, but we will discuss these cases separately.
A muffler is a part of a car's exhaust system that absorbs car noise. The better this detail, the lower the sound. The question immediately arises, which muffler is better, and which is not? If you want to know the answer, read on.
What is the difference between mufflers for a car
There are dozens of types of mufflers on the Russian auto parts market. European, Russian, Chinese, Turkish - how can a consumer choose a high quality car muffler. Some are more expensive, others are cheaper. Some are dyed, others are not. The brand of some is known to everyone, while the name of others does not say anything. We're not going to endorse a specific brand, we're just here to help you make the right choice.
The main criterion for the quality of the exhaust system is the metal from which it is made.
Automobile mufflers are made from the following materials:
- ordinary steel;
- stainless steel;
- aluminized steel.
Most mufflers for foreign cars are made of aluminized steel. This material is more resistant to corrosion than regular steel, although the cost of an aluminized muffler is not much higher than that of steel. It is for this reason that Europe has completely stopped the production of conventional steel mufflers. In Russia, black steel mufflers are produced to this day.
Parts made of ordinary steel last no more than a year, while high-quality aluminized mufflers can be used from 4 to 6 years. Notice the "quality". Unfortunately, some are not of good quality. Their service life does not exceed one year.
The problem is that it is impossible to evaluate the quality of an aluminized muffler by eye. But it can be easily distinguished from a muffler made of "black" steel. Black steel parts are usually painted silver, while unpainted parts are black. Silencers are painted only so that they do not rust before sale. This is where the useful properties of painting end.
Exhaust system parts made of stainless steel are rare on the open market. As a rule, these are original spare parts of well-known manufacturers.
This is due to the fact that the price of stainless steel is much higher, and motorists do not want to pay this difference in money.Some car owners do not plan to drive their car for more than 2-3 years, others will prefer to replace the muffler after the same 3 years.
It is for these reasons that stainless steel mufflers are not produced in large quantities.
Another important aspect of the quality of a muffler is its internal filling. It's just that mufflers from different manufacturers look similar in appearance. Exhaust sound absorption depends on several factors:
- the presence of a two-layer body;
— quality of internal perforated pipes;
- the volume of the internal cavity of the muffler;
- heat resistance of sound-absorbing packing and its resistance to blowing.
The cost of a silencer is directly proportional to its volume. One way to reduce the price is to simplify the design. Many unscrupulous manufacturers choose this path, which negatively affects the muffler's ability to process the exhaust stream.
Reducing the volume of the can and simplifying the internal structure, leads to a louder exhaust sound. And the use of low-quality acoustic filler leads to a rapid loss of its sound-absorbing properties. As a result, a "drum" effect appears.
