Aluminium Versus Stainless Steel

Aluminum Versus Stainless Steel

The domains of metallurgical sciences have created a revolution in the construction and industrial world. The metal and alloys are promoting integration in mechanisms that are commendable. The efficient applications are all surrounded by kitchenware to spacecraft engineering.

Ferrous and non-ferrous metals are largely produced, but ferrous metals dominated the production across the globe.

The irrevocable properties like sturdiness, malleability, and surface finish contributing to the business in engineering applications. The selection of any metal requires a detailed study of application.  Alloy performance can be critically viewed by efficient operation and longevity in adverse conditions like extreme weather and temperatures. Aluminum and stainless steel are integrative needs of many constructions and engineering projects. The differences between the two will decide, to use or not to use, or to use in conjunction.

Aluminum

Aluminum is a non-ferrous, abundant metal and used for its colossal characters. It is lightweight, malleable, strong, corrosion resistive, and posses’ good electrical conductivity. Aluminum is machinable and non-magnetic in nature. Its adaptability is converted into a wide zone of applications.

Stainless Steel

Stainless steel is illustrious for its corrosion resistance and aesthetic appearance. It contains a high concentration of chromium. Its applications are vast and content. It has high strength, oxidation, mechanical properties, etc. Aluminum alloys and stainless steel, both offer considerable corrosion resistance in environments.

Difference between Aluminum and Stainless Steel

Stainless steel and aluminum are competing tough. Both are practical and in the claim. Apparently, both look similar and familiar, still distinctive in properties and applications. Aluminum posses better malleability, machinability than stainless steel, whereas stainless steel features better weldability and non-reactivity for edibles.

Production of Aluminum and Stainless Steel

The aluminum is extracted from bauxite and converted into aluminum oxide. Aluminum is again extracted from aluminum oxide by using electrolysis and other processes.

Stainless steel is extracted from iron ore, mixed with chromium and other alloying agents like nickel, manganese, molybdenum. The amalgamation is passed into an electric furnace and melted for a fixed time, then cast into various shapes.

Chemical composition

Aluminum is generally alloyed with copper, zinc, magnesium, and lithium. The trace contents of chromium, titanium, lead, and bismuth are also in attendance.

The chromium, nickel, molybdenum, titanium, and niobium are amalgamations for the stainless steel in high content.

Physical properties

In comparison, aluminum has approximately one-third density of stainless steel. Hence it is lighter than stainless steel. That is why aircraft are made up of aluminum. Stainless steel is considerably stronger than aluminum.

The thermal conductivity of aluminum is largely higher than stainless steel and proves significance in heating applications. It is used in heat exchangers, car radiators, air conditioning, cooking utensils, and cookware.

Physical parametersAluminumStainless steel (304)
Density2.7 g/cm³8.00 g/cm³
Melting point660.3°C1450 °C
Modulus of Elasticity68.3193 Gpa
Thermal conductivity205 W/m.K16.2 W/m.K
Tensile strength76-84Mpa510-620 Mpa
Thermal expansion  22.2× 10-6/K16 ×10-6/K

Cost

If the comparison of cost is made by weight, aluminum is expensive. Aluminum has less density than stainless steel. But if a comparison is done by volume, stainless steel is more costly than aluminum. Typically, stainless steel is of higher cost than aluminum.

Aluminum and stainless steel in the aviation industry

The chronological metal used in the aviation industry is aluminum. Aluminum is used far and wide in modern crafts. It is strong, ductile, machinable, cheaper, and constitutes one-third weight of stainless steel. Aluminum alloys are used in a component like aircraft skins, aircraft structures, cowls, baffle plating, fuel tanks, and landing mats, etc.

Stainless steel has strength and superior corrosion-resistant features. It can bear impacts better than aluminum. The high-temperature confrontation and corrosion preventing nature evoke production of aerospace parts, fasteners, landing gear parts, and fuel tanks.

Aluminum Applications

Aluminum has applications in food preparation and packaging, transport, energy-generating components, and electrical transmission. Stainless steel is widely used in the food processing industry, heavy-energy industries, medical equipment, automation, and architectural-construction companies.

Aluminum and stainless steel are comparative and superlative. Duplex stainless steel and aluminum alloys are creating the scope of future and competition.

Application of Stainless steel

Stainless Steel found use in different sectors depending upon the type of grade as follows:

  • SS 304 / 304 L – Tanks, Storage vessels, Sinks, Cutlery, Architecture.
  • SS 309/ 310- Furnace, Kiln, Catalytic convertors.
  • SS 318, 316 L – Chemical Storage Tanks, Pressure Vessels and Piping.
  • SS 321, 316 Ti – After burners, Super Heaters, Compensators, Expansion Bellows.
  • SS 200 series – Dishwashers, Washing Machines, Cutlery, Cookware, Food beverage equipment.

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