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Aluminum Alloy Castings and Their Defects

Aluminum Alloy Casting

Several factors influence the quality of Aluminum Alloy Casting. Some of them are resistance to corrosion, airtightness, and lightweight. Various tests have been conducted on these products to measure their strength, quality, and durability.

Airtightness

Various aluminum alloys have different physical and chemical properties. Therefore, their castings also have different properties. However, in order to produce a good aluminum alloy casting, the casting must be tailored to the alloy’s properties.

Depending on the alloy, the castings have different shrinkage rates. The shrinkage rate affects the shape of the casting and also the mechanical properties. Castings of aluminum alloy with thinner walls have a higher cooling velocity than those with thick walls. This can be advantageous to the airtightness of the casting.

Generally speaking, the performance of the casting process is a combination of the three factors, namely, the casting size, the shape of the pouring riser system, and the pouring method. The size of the riser is more important than the concentration of shrinkage.

Lightweight

Using aluminum alloy castings is a great way to keep weight down while maintaining the functionality of the part. Aluminum alloys are used in a wide range of applications, from automobiles to electronics. The material is lightweight, durable, and provides excellent corrosion resistance.

Aluminum castings are also commonly used in marine grade applications. They provide excellent rigidity and corrosion resistance, and lend resilience to hand-held devices. The material also provides EMI/RFI shielding, which is beneficial in the telecom industry.

In addition to its durability, aluminum is an excellent thermal conductor. It also has a good strength to weight ratio, and can be easily cast or wrought. The density of aluminum is over 2,700 kg/m3, which makes it a good choice for heat dissipation.

One of the most popular applications for aluminum is in electronic products. Aluminum has excellent conductivity, making it a great choice for EMI/RFI shielding. The material is also great for dissipating heat, which helps keep your electronics cool.

Resistance to corrosion

Despite aluminum alloy’s high strength and durability, corrosion is an issue. In order to prevent corrosion, aluminum alloy must be isolated from the environment. Aluminum has a strong affinity to oxygen and it forms an inert oxide film on its surface. This film serves as a protective layer, which prevents the metal from rusting in an oxidizing environment. However, it is also dissolved in strong bases and acids.

The stability of this film is dependent on the pH value of the environment. It is generally stable in the pH range of 4.5 to 8. However, its stability may be compromised if the pH value is below four. Its stability also depends on the temperature and conductivity of the water.

In order to improve aluminum alloy corrosion resistance, metal foundries often add a higher proportion of silicon. Silicon has the ability to increase the strength of aluminum alloys during aging and decrease their density. However, this process can cause air bubbles to form in the casting.

Removable bollards

Depending on your needs, a bollard can be functional, ornamental, or both. They are a great solution for managing pedestrian and vehicular traffic and are suitable for both parking lots and streetscapes alike. Bollards also come in different heights, from the diminutive 35 3/8 to the massive 35 1/2 inches. Some are even made to fit over a standard four inch pipe.

Removable bollards are also available with a telescopic axis for easier installation and removal. Some are even equipped with a shoe pipe holder for embedment in new concrete. Various options are available including a tamper proof version. Some models are even fitted with an LED light to alert pedestrians of their presence in the dark. Bollards can be made of various materials, from stainless steel to aluminum and aluminum alloys, including bronze and aluminum.

Tests conducted on aluminum alloy castings

Several tests have been carried out on aluminum alloy castings to determine their forming capabilities. This study aims to provide a complete knowledge of aluminum alloy castings and their defects.

The main aluminum alloy castings were artificially aged to obtain their mechanical properties. These alloys were then subjected to fatigue tests. Some of them were subjected to dye penetrant liquid surface examination. These castings were tested for two x 10 6 cycles.

These tests revealed that the main aluminum alloy castings had relatively high strengths to density ratios. These alloys also had high mechanical properties. However, they had low ductility. These alloys are used for various applications.

Some of these alloys also contain copper. Copper can increase the strength of the alloy and improve the mechanical properties. However, it can also decrease corrosion resistance. In addition, the presence of chloride ions also affects corrosion resistance.