Galvanized Steel Vs Aluminum

Stainless Steel Vs Aluminum: The Ultimate Guide

Stainless steel and Aluminum are similar in appearance, yet they are different. This article aims to look into the fundamental differences between the two metals. It will also discuss the various applications of each metal, their properties, and the considerations in selecting which metal to use.

What Is Stainless Steel?

It is a ferrous alloy that contains a minimum of 11% chromium. Additionally, this metal may also have carbon, other metals, and nonmetals to help it achieve the desired properties.

Notably, it is resistant to corrosion due to the presence of chromium. Chromium forms a protective layer on the metal.

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What Is Aluminum?

It is a chemical element of atomic number 13. Normally, it is characterized by a lower density than other popular metals. Additionally, its affinity toward oxygen is very high and resembles silver in its appearance and reflective ability to light.

What Is Aluminum
Strength To Weight Ratio_ Aluminum Vs. Stainless Steel

Strength To Weight Ratio: Aluminum Vs. Stainless Steel

Stainless steel is considerably stronger than Aluminum. Aluminum weighs about one-third of stainless steel. For this reason, Aluminum is commonly used to manufacture aircraft and bicycles.

Aluminum is also standard in the automotive industry. Though stainless steel is much stronger than Aluminum, its strength is poorer compared to Aluminum.

Stainless Steel Vs Aluminum Weight

Stainless steel is considerably heavier than Aluminum. Aluminum weighs about one-third of stainless steel. Remember, the light weightiness of aluminum makes it applicable in many industries. For this reason, Aluminum is commonly used to manufacture aircraft and bicycles. Aluminum is also standard in the automotive industry.

Though stainless steel is much stronger than Aluminum, its strength is poorer compared to Aluminum. Stainless steel. On the other hand, is heavier. Its strength and weight make it applicable in the architectural industry.

Stainless Steel Vs Aluminum Weight
Stainless Steel Vs Aluminum Price

Stainless Steel Vs Aluminum Price

Generally, Aluminum and stainless steel cost about the same per kilogram in the market. In terms of volume, more aluminum is purchased at the same price. The volume factor makes stainless steel more expensive than aluminum. Aluminum being lighter in weight is more cost-effective. The price is lower because you can buy more Aluminum for the same amount.

Stainless Steel Vs Aluminum Rust Resistance

With the excellent corrosion resistance properties that Aluminum has, it does not rust. Stainless steel, however, is more resistant to rust. The chromium acts as a corrosion resistance agent. Remember, chromium increases the resistance to corrosion due to its non-porous nature.

Aluminum has a high oxygen affinity and is resistant to corrosion. The resistance is due to the passivation layer that forms on Aluminum during oxidation. An oxidized aluminum surface turns white and can sometimes become pits.

Stainless Steel Vs Aluminum Rust Resistance
Conductivity Of Aluminum And Stainless Steel

Conductivity Of Aluminum And Stainless Steel

Stainless steel is a poor conductor of electricity. On the other hand, Aluminum is a good conductor of electricity.

Likewise, Aluminum is a better conductor of heat. For this reason, stainless steel is preferred in high-temperature applications. Aluminum will soften when exposed to higher temperatures.

Heat Resistance: Aluminum Vs Stainless Steel

Stainless steel has a melting temperature of about 2500F, while the melting temperature of Aluminum is about 1220 °F. At 400 °F, Aluminum will begin to soften.

Stainless steel is more resistant to heat than Aluminum. At low temperatures, Aluminum holds the advantage over stainless steel. The tensile strength of Aluminum will increase with the decrease in temperature. On the other hand, stainless steel will become brittle.

Heat Resistance_ Aluminum Vs Stainless Steel
Welding Stainless Steel Vs Welding Aluminum

Welding Stainless Steel Vs Welding Aluminum

It is relatively easy to weld stainless steel. Different grades of stainless steel have different weldability. For instance, austenitic grades are readily weldable.

Stainless steel weldability depends on the family to which they belong. Australian standard AS 1554.6 gives the pre-qualifications for weldability. The standard also specifies the procedure for the welding in each application.

Magnetic Properties: Stainless Steel Vs. Aluminum

Under normal circumstances, Aluminum is not magnetic. This is due to its crystal structure. It is called paramagnetic material, just like magnesium and lithium.

Stainless steel, on the other hand, has varying magnetism depending on the chemical composition. For it to be magnetic, it must have iron, and the crystal structure is arranged in ferritic and martensitic structures. Some grades have a high work hardening rate and are characterized by the most increased magnetic permeability.

Magnetic Properties_ Stainless Steel Vs. Aluminum
Corrosion Resistance Between Stainless Steel Vs Aluminum

Corrosion Resistance Between Stainless Steel Vs Aluminum

Stainless steel is composed of iron, chromium, manganese, copper, and nickel. The chromium acts as a corrosion resistance agent. This chromium increases the resistance to corrosion due to its non-porous nature.

Aluminum has a high affinity to oxygen and is resistant to corrosion. The resistance is due to the passivation layer that forms on Aluminum during oxidation. An oxidized aluminum surface turns white and can sometimes become pits. In extreme acidic or base environments, Aluminum corrodes rapidly and has catastrophic results.

Chemical Composition Of Stainless Steel Vs Aluminum

Stainless steel alloys are composed of 0.01 – 0.08 % carbon, 1.39 – 2.0 % manganese, 0.002 – 0.08% Sulphur, 0.4 – 1% silicon, 8 – 11.2% nickel

Aluminum alloys are composed of 0 – 4.4% copper, 0.3 – 2.5 % magnesium, 0 – 0.6 manganese, 0 – 7 % silicon, and 0 – 5.6 % zinc.

Chemical Composition Of Stainless Steel Vs Aluminum

Fabricating Stainless Steel Vs Aluminum

Fabricating Stainless Steel
Fabricating Aluminum

Depending on parts you want to make, you can handle aluminum fabrication and stainless steel fabrication successfully. Among the most common fabrication techniques include:

Extrusions – This process exerts less amount of stress on metal alloys. Extrusion forces a material to change its shape to the die used.

Adhesive bonding – It involves the assembly of metal parts.

Forming – This process involves rolling, stamping, and bending.

DrawingThe drawing process stretches a metal by pulling it through a tapered die.

Machining – The machining process entails turning and milling metal.

MIG and TIG welding – Welding involves melting the thread of metal to bind pieces of metals.

Casting – Liquid metal is poured into a mold of the desired product shape. Casting is best when strength and resistance to wear are critical.

In short, both stainless steel and aluminum are suitable for virtually all types of fabrication processes.

Advantages Of Stainless Steel
Advantages Of Stainless Steel

High tensile strength and impact resistance – it has low susceptibility to brittleness, is adamant, and is very durable.

Long-term value – the total life cycle cost of steel stacks up to other metals.

Heat resistant – the resilience of stainless steel to heat is very high. It can retain strength at very extreme temperatures.

Corrosion resistance –is one of the best qualities of stainless steel.

Advantages Of Aluminum
Advantages Of Aluminum

Light weight – it weighs about one-third of stainless steel.

Good malleability – it is easy to machine

Good conductivity – it is a good conductor of both electricity and heat.

High ductility

Aluminum is recyclable

Light weight – it weighs about one-third of stainless steel.

Good malleability – it is easy to machine

Good conductivity – it is a good conductor of both electricity and heat.

High ductility

Aluminum is recyclable

Disadvantages Of Stainless Steel
Disadvantages Of Stainless Steel

It isn’t easy to manufacture.

Also, it is very costly

It can show dirt and grease in particular environments.

Disadvantages Of Aluminum
Disadvantages Of Aluminum

It is weaker in strength.

Besides, it is exceptionally costly when compared to steel of the same strength.

Types Of Stainless Steel Vs Aluminum

Types Of Stainless Steel
Types Of Stainless Steel

These grades include;

Austenitic stainless steels – They have high carbon content and are prone to intergranular corrosion.

Ferritic stainless steels – They are the easiest to weld stainless steel.

Martensitic stainless steels – The carbon content in martensitic SS is higher than ferritic and austenitic.

Duplex stainless steel – They are a hybrid of austenite and ferrite stainless steel.

Precipitation hardening stainless steel – They form through intermetallic precipitation blocking dislocations within stainless steel.

Types Of Aluminum
Types Of Aluminum

Some of the most popular alloys of aluminum are:

6061- Aluminum alloy – It is more common and can be found in every market today. Besides, it has good resistance to corrosion, weldability, above-average strength, and machinability.

5052 aluminum alloy – The 5052-grade aluminum alloy is excellent due to its weldability, good product finish, and significant resistance to salt water corrosion. It is, however, not easy to machine. And cannot be heat-treated.

Other alloys are 1000 series, 2000 series, 3000 series, 4000 series, 7000 series and 8000 series.

Applications Of Stainless Steel Vs Aluminum

Applications Of Stainless Steel
Applications Of Stainless Steel

Kitchen equipment – heat and corrosion resistance properties make it suitable for kitchen appliances and equipment such as cutlery and food prep tables

Surgical tools and medical equipment – stainless steel has high corrosion resistance features that are applicable in making surgical implants and scissors

Architectural applications require strength and durability present in stainless steel.

You can use stainless steel in the construction of bridges and buildings.

The automotive industry makes rail cars and engines

Applications Of Aluminum
Applications Of Aluminum

The transportation industry, due to its lightweight and corrosion resistance, e.g., automotive, train rails, spaceships, airplanes

The electrical industry, due to its ductility, conductivity, and low density –makes long-distance powerlines

Architectural industry uses aluminum due to its malleability, high strength-to-weight ratio, and cost-efficiency.

Used to make window frames, high-rise buildings

Household appliances due to good thermal conductivity. Used in the manufacture of dishwashers, washers, dryers, refrigerators

Stainless Steel Surface Finishes

Slag, Oxide, And Splatter Removal
Slag, Oxide, And Splatter Removal

Slags can be removed by hammering. You remove wet splatter and oxide films using SS wire brushes.

Grinding
Grinding

One must be careful during grinding not to cause overheating or discoloration associated with overheating.

Polishing
Polishing

It involves using mesh abrasive to remove grinding marks. To prevent contamination, you must strictly put aside the tools for SS works.

Pickling
Pickling

Some welding results in colored oxides that you must remove to restore the passivity of the stainless steel.

Passivation
Passivation

Pickling leaves the metal unprotected, putting a new layer in place to restore the corrosion resistance.

Aluminum Surface Finishes

Mechanical Finishes
Mechanical Finishes

It is buffed, polished, sanded, ground, or blasted to improve the surface quality and prepare it for other cosmetic finishes.

Pretreatment
Pretreatment

Etched or cleaned with alkaline or acidic material. A pretreatment coating is applied to enhance the adhesion and corrosion-resistant properties.

Bright Dipping
Bright Dipping

It gives Aluminum a mirror-like finish. Aluminum is placed in a unique dip solution and anodized to thicken the protective layer.

Anodizing
Anodizing

Electrochemical process that gives added protection from the oxide formed on the Aluminum. Liquid paint involves removing the volatile organic compounds in the liquid coating to form a film on the extrusion.

Powder Coating
Powder Coating

It is ideal for compliance with environmental regulations on VOCs.

Sublimation
Sublimation

A powder base coat is applied and wrapped in the thin film of the pattern through sublimation.

People Also Ask:

Which Is Healthier Between Stainless Steel And Aluminum?

Stainless steel resists more damage than Aluminum due to its high density. It is advisable to use stainless steel over Aluminum.

Between Aluminum And Stainless Steel; Which One Is Suitable For Outdoor?

Aluminum is more suitable for outdoor applications due to its vast weather-resistant features.

Is Aluminum Better Than Stainless Steel?

It’s hard to determine which metal is better. Strength and weather resistance are the major deciding factors.

Is Aluminum Harder Than Stainless Steel?

No, it’s not more complicated than stainless steel. It’s more challenging to cut steel than Aluminum.

More Resources:

Sheet Metal Fabrication Process

Stainless Steel

Aluminum Alloys

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