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Beryllium copper castings offer many advantages in demanding commercial, industrial and aerospace applications.
Advantages of Beryllium Copper Castings
Beryllium copper castings are not soft at all. When heat-treated, this high-strength alloy provides high thermal and electrical conductivity. Beryllium copper has a higher hardness value than many steels, but has similar or higher thermal conductivity than aluminum. Beryllium copper castings are malleable, easily welded, and very easy to machine. The material is also resistant to non-oxidizing acids and plastic breakdown products.
Beryllium copper cast alloys with 2.0% to 2.75% beryllium have excellent wear resistance, toughness and anti-wear properties. In challenging geometries with thin walls and fine internal channels, beryllium copper is excellent at replicating finer details.
Although beryllium copper exhibits high electrical conductivity, it does not spark and is nonmagnetic. The material meets the requirements of the ATEX Directive and is safe for use in "Ex areas" where hazardous, flammable or combustible vapours, liquids, dust or residues may be present.
Aluminum castings are widely used throughout the marine industry. Aluminum's high weight-to-strength ratio and non-corrosive properties make aluminum castings ideal for marine applications.
Why are aluminum alloys used in marine applications?
Aluminum is a very reactive metal, which means it has the property of oxidizing very quickly. While a weak point for most metals, this quality is actually the key to its ability to resist corrosion. When oxygen is present (in air, soil or water), aluminum reacts immediately to form alumina. This aluminum oxide layer is chemically bonded to the surface and seals the core aluminum to prevent any further reaction. This is quite different from oxidation (corrosion) of steel or iron, where the rust expands and flakes off, constantly exposing new metal to corrosion. Aluminum's oxide film is tough, hard, and instantly renews itself. Therefore, aluminum alloys are widely used in marine applications due to their corrosion resistance.
Why are aluminum castings used in marine applications?
Casting methods for marine aluminum alloys can be gravity die casting, die casting or sand casting. Choose any aluminum casting process according to the structure of the component. For example, for ADC12, a material with very thin wall thickness, die casting is preferred. But if the quantity is not large, in order to save cost, we can also choose gravity casting.
The casting process offers many advantages over other metal forming processes such as forging, welding, stamping, rolling, extrusion, etc. The reasons for the success of the foundry process are:
Due to physical properties, some metals can only be cast because they cannot be reshaped into rods, rods, plates or other shapes.
This is a process that is highly adaptable to mass production requirements. A large number of given castings can be produced quickly.
Certain lightweight aluminum alloys can only be produced as castings due to their respective advantages and disadvantages.
Exhibits excellent load-carrying qualities.
Advantages of Marine Aluminum Castings
Low cost, precision, long life tools
Unit cost savings compared to alternative manufacturing methods
Durable, cleanable finish that can be painted, powder coated or anodized.
Lightweight aluminum alloy with exceptional strength
Ability to cast complex features
excellent corrosion resistance
The difference between gray iron and ductile iron is the type and structure of carbon present in them. Of course, the question is which one is right for your project? Before we look for possible answers, let's examine the differences between gray and ductile iron castings.
main difference
Ductility - Ductility is determined by a greater percentage of elongation under tension. The addition of magnesium to ductile iron means that the graphite is spherical/spheroidal, giving it greater strength and ductility than flake gray iron. For example, 18% elongation can be easily achieved with ASTM A395 and A536 grade 60-40-18 material.
Tensile Strength and Yield Strength - There are definitely differences in the tensile strength and yield strength of gray and ductile iron. Ductile iron has a minimum tensile strength of 60,000 psi and a minimum yield strength of 40,000 psi. There are many grades of gray cast iron according to ASTM A48 standard. While gray cast iron does not have a measurable yield strength, the tensile strength ranges from 20,000 psi – 60,000 psi.
Impact – Impact strength, also known as toughness, is a measure of a metal's ability to resist fracture when it absorbs an impact (collision). Ductile iron is more impact resistant, capable of resisting impacts of at least 7 foot-pounds (compared to 2 pounds for gray iron). This means that while ductile iron can be used in critical applications involving impact, gray iron has limitations that prohibit its use for certain purposes.
Thermal Conductivity - Ductile iron has lower thermal conductivity than gray iron. Specifically, the graphite phase in gray cast iron gives it very high thermal conductivity, since the heat transfer takes place through the graphite flakes. The isolated nodules of graphite in ductile iron greatly reduce its thermal conductivity - in fact it is not much more conductive than steel. As the carbon content increases, the thermal conductivity increases. This means that the lower strength gray iron has a higher thermal conductivity. If the main reason for choosing gray cast iron is thermal conductivity, design engineers need to keep this in mind. Gray cast iron has high thermal conductivity and is an excellent choice for components subject to thermal shock, such as brake drums.
Vibration Damping - Internal friction is the way a material absorbs vibrational energy. Gray iron dampens vibrations more effectively than ductile iron because gray iron exhibits inelastic behavior at very low stresses. Higher damping capacity enhances fatigue resistance because the duration of stress at or above the fatigue limit is reduced. This increased resistance to fatigue is the most beneficial aspect of the higher damping capacity. Another major benefit is the reduction of possible vibration and noise from mechanical parts.
One of the most popular ways to manufacture durable and high-quality components is through casting. Casting allows for a high level of detail, which results in no additional fabrication or assembly being required. While many different materials can be cast, steel and iron are two of the most popular due to their excellent mechanical properties for a wide range of applications.
Cast iron generally refers to gray cast iron, ductile iron and malleable cast iron. It is an iron casting with a carbon content higher than 2%.
Cast steel usually refers to ordinary carbon steel and alloy steel. It is a steel casting with a carbon content of less than 2%.
Therefore, the chemical composition and raw materials of cast iron and cast steel are not much different.
Corrosion resistance
In terms of corrosion, iron has better corrosion resistance than steel. But that doesn't mean that both are immune to corrosion. If left unprotected, both metals will oxidize in the presence of moisture. Eventually, they will break down completely. To prevent this, the coating is recommended for steel and iron castings.
cost
Cast iron is generally less expensive than cast steel because of the lower material costs, energy and labor required to produce the final product. Although raw steel is more expensive, prefabricated steel is also available. These include sheets, rods, rods, pipes and beams.
Castability
Cast iron is relatively easy to cast because it pours easily and doesn't shrink like steel. This fluidity makes cast iron an ideal metal for buildings or ornate ironwork structures such as fences and street furniture.
Advantages and disadvantages of cast iron
Good casting properties of gray cast iron are.. good vibration damping, good wear resistance, good machinability and low notch sensitivity. However, it has low tensile strength and elongation. Therefore, it can only produce some metal parts with low physical requirements. Protective cover, cover, oil pan, hand wheel, shelf, bottom plate, hammer, small handle, base, shelf, box, knife, bed, bearing seat, workbench, wheel, cover plate, pump, valve, pipe, Flywheel, motor block, etc. As for higher grades, gray cast iron can withstand greater loads and some degree of tightness or corrosion resistance. This allows for some of the more important castings such as cylinders, gears, bases, flywheels, beds, cylinder blocks, cylinder liners, pistons, gearboxes, brake wheels, coupling plates, medium pressure valves, etc.
Ductile iron and malleable iron have high strength, ductility and heat resistance and toughness. So it has a wider range of applications and, in some cases, can replace carbon steel. However, its production technology is high. The production process is more complicated. This makes the production cost higher than ordinary gray cast iron and cast steel. Therefore, the casting defects of ductile iron are more. There are many areas where ductile iron is used, such as pressure piping and fittings, automotive applications, agriculture, road and construction applications, and general engineering applications.
Advantages and disadvantages of cast steel
The main advantage of cast steel is design flexibility. Casting designers have the greatest freedom of design choice. This allows complex shapes and hollow section parts.
Cast steel offers the flexibility and greatest variability of metallurgical manufacturing. Different chemical compositions and controls can be selected to suit different requirements of different projects. This provides different heat treatment options across a greater range of mechanical properties and properties. Also provides good weldability and machinability.
Cast steel is an isotropic material that can be made into steel castings with high overall structural strength. This increases the reliability of the project. Combined with design and weight, advantages such as short lead times, price and economy give cast steel a competitive advantage.
Steel castings have a wider range of weights. The weight is extremely small, and precision castings with only a few tens of grams can be invested. The weight of large steel castings can reach several tons, tens of tons or hundreds of tons.
Steel castings can be used in a variety of working conditions. Its mechanical properties are superior to any other cast alloys, as well as various high-alloy steels for special purposes. To withstand high tensile stresses or dynamic loads on components, it is important to consider pressure vessel castings. In low temperature or high temperature, large and important part load key parts should be preferentially used steel castings.
However, the shock absorption, wear resistance and fluidity of cast steel are relatively poor. Compared with cast iron, casting performance is poor. In addition, the cost is higher than ordinary cast iron.
So, when it comes to cast iron and cast steel, they each have pros and cons. One of the two should be selected based on the application and its physical characteristics.