What is the difference between 6061 aluminium and 5083 sheet?

Aluminum 6061 is an alloy made up of aluminum, magnesium, and silicon. It offers excellent formability, weldability, and corrosion resistance.
Aluminum 5083 is an alloy made of aluminum, magnesium, and tiny amounts of manganese and chromium. It is renowned for its superior corrosion resistance and strength.

Aluminum 6061 has high strength qualities, with a yield strength of 40,000 psi (276 MPa) and a tensile strength of 45,000 psi (310 MPa). It is widely employed in structural applications.
Aluminum 5083 is a high-strength alloy with a yield strength of around 30,000 psi (207 MPa) and a tensile strength of about 45,000 psi (310 MPa). It is highly recognized for its durability in aquatic conditions. 

Corrosion Resistance: Aluminum 6061 offers good corrosion resistance compared to other aluminum alloys. It develops a protective oxide coating on its surface to assist resist corrosion.
Aluminum 5083 has exceptional corrosion resistance, especially in saltwater and marine conditions. It is extremely resistant to corrosion induced by seawater and other harsh substances.

Aluminum 6061 has numerous applications, including structural components, automobile parts, bicycle frames, electrical connections, and general machining.
Aluminum 5083 is largely utilized in marine applications, including shipbuilding, boat hulls, offshore structures, and other components that are subjected to saltwater and harsh environments. It's also used in pressure vessels, transportation equipment, and architectural components.

Aluminum 6061 has strong weldability and may be easily welded using TIG and MIG welding processes.
Aluminum 5083 has good weldability, especially when employing the right filler material. It is typically welded with the MIG welding method.