1 The following is a list of metals and alloys Plain carbon

1. The following is a list of metals and alloys:

Plain carbon steel

Magnesium

Brass

Zinc

Gray cast iron

Tool steel

Platinum

Aluminum

Stainless steel

Tungsten

Titanium alloy

Select from this list the one metal or alloy that is best suited for each of the following applications, and cite at least one reason for your choice:

            (a) The block of an internal combustion engine

            (b) Condensing heat exchanger for steam

            (c) Jet engine turbofan blades

            (d) Drill bit

            (e) Cryogenic (i.e., very low temperature) container

            (f) As a pyrotechnic (i.e., in flares and fireworks)

            (g) High-temperature furnace elements to be used in oxidizing atmospheres   

Solution

(a) The block of an IC ENGINE are normally cast from either a suitable grade of iron or aluminium alloy.The aluminium block is much lighter in weight and has better heat transfer to the coolant, nut Iron blocks retain some advantages and continue to be used by some manufacturers.

(b) Condensing heat exchanger for steam:Steel is generally used because it is cheap , relatively easy to form and conducts heat very well.Steel is used mostly for only crude oil applications because any other like water and even mildly corrosive fluds will have rust prone and corrosive problem.Generally copper alloy is prefered(which is not listed)

(c) Jet engine turbofan blades:Titanium alloy is preferable because each fan blade consists of two blade skins produced by shaping molten Titanium in a hot press.When removed, each blade skin is welded to a mate, with a hollow cavity in the center. To increase the strength of the final product, this cavity is filled with a titanium honeycomb.

(d) Drill bit: Tool steel (generally refers a variety of carbon and alloy steels) because they are very distinctive hardness, resistance to abrasion and deformation and their ability to hold a cutting edge at elevated temperatures.

(e)Cryogenic(i.e., very low temperature) container :For a cryogenic (low-temperature) container, an aluminum alloy would be the best choice; aluminum alloys have an FCC crystal structure, and therefore, are ductile at very low temperatures.

(f)As a pyrotechnic (i.e., in flares and fireworks):Magnesium is the best choice because it ignites easily and burns readily in air with a very bright flame.

(g)High-temperature furnace elements to be used in oxidizing atmospheres:-Platinum is the best choice for high-temperature furnace elements to be used in oxidizing atmospheres because it is very ductile, has a relatively very high melting temperature, and is highly resistant to oxidation.