A Trivia Quiz On Types Of Aluminium Alloy!

Grain refinement in Al alloys can be achieved through multiple methods. Fast cooling of the melt helps in reducing the grain size by preventing the growth of grains during solidification. Adding grain refinement elements, such as titanium or zirconium, promotes the formation of fine grains in the alloy. Cold working, which involves plastic deformation of the material at low temperatures, also contributes to grain refinement by breaking down existing grains and creating new smaller grains. Therefore, all of the mentioned methods - fast cooling of melt, adding grain refinement elements, and cold working - can be used to achieve grain refinement in Al alloys.

The 1XX.X designation is given to cast type of aluminium alloys. This means that alloys with this designation are specifically used for castings, which are produced by pouring molten metal into a mold and allowing it to solidify. Cast aluminium alloys have different properties compared to other types of aluminium alloys, making them suitable for applications where casting is required, such as automotive parts, aerospace components, and household appliances.

Age hardening is a process used to strengthen aluminium alloys by subjecting them to a combination of heat treatment and rapid cooling. This process involves the precipitation of small particles within the alloy, which hinders the movement of dislocations and increases the strength of the material. Age hardening is particularly effective in strengthening aluminium alloys, making them stronger and more resistant to deformation and wear.

The 6XX.X designation is unused in the 4-digit designation of aluminium alloys.

Sodium causes hot cracking in 5XXX alloys. Hot cracking, also known as solidification cracking, occurs during the solidification process of the alloy. Sodium is known to have a detrimental effect on the solidification process, leading to the formation of cracks. It has a low melting point and can easily penetrate the grain boundaries, causing weakening and cracking of the alloy. Sodium is particularly problematic in 5XXX alloys, which are commonly used in structural applications and require high strength and good weldability. Therefore, the presence of sodium can significantly compromise the mechanical properties of the alloy, making it susceptible to hot cracking.

Magnesium decreases the density of Al alloys. When magnesium is added to aluminum alloys, it forms a solid solution, which leads to a decrease in the overall density of the alloy. This is because magnesium has a lower atomic mass than aluminum, resulting in a lighter material. The reduced density can be advantageous in various applications where weight reduction is desired, such as in the automotive and aerospace industries.

Nickel and chromium are both known for their corrosion resistance properties. Nickel helps to decrease corrosion by forming a protective layer on the surface of the metal, preventing it from coming into contact with corrosive elements. On the other hand, chromium improves corrosion resistance by forming a thin oxide layer on the surface of the metal, which acts as a barrier against corrosion. Therefore, the correct answer is "decrease, improve" as nickel decreases corrosion and chromium improves corrosion resistance.

Cu is usually kept

Silicon is known for its ability to enhance fluidity and corrosion resistance in materials. However, it does not increase the thermal expansion coefficient. Therefore, the correct answer is "none of the above" as silicon does not reduce fluidity, corrosion resistance, or increase the thermal expansion coefficient.

Cold working is a process in which a metal is deformed at room temperature, usually through processes like rolling, bending, or drawing. This deformation causes dislocations in the crystal structure of the metal, which increases its strength. Therefore, cold working can be used to increase the strength of non heat-treatable alloys.