Cast Aluminum Alloys: An Overview

MODULUS METAL | ALUMINUM SAND CASTING FOUNDRY IN TURKEY

General Information Table

Category	Description
1xx.x Series	Pure aluminum
2xx.x Series	Copper-alloyed
3xx.x Series	Silicon, copper, and magnesium alloyed
4xx.x Series	Silicon-alloyed
5xx.x Series	Magnesium-alloyed
6xx.x Series	Unused (reasons for non-use explained separately)
7xx.x Series	Zinc-alloyed

6xx.x: series is unused. ( Why is the 6xx.x series unused? Here's the answer )

Strengths and Limitations Table

Aspect	Details
Strengths	Good fluidity, corrosion resistance, feeding ability, and strength.
Limitations	Lower ductility and strength compared to wrought aluminum alloys.

Alloy Designation System Table

Component	Explanation
First Digit	Identifies the principal alloying element.
Next Two Digits	Specify the particular alloy variant within the series.
Decimal Digit	Indicates product form: .0 for castings, .1 or .2 for ingots.
Special Indicators	Prefix (e.g., A360.0) denotes modifications; age-hardening alloys include a “T” suffix.

For the 1xx.x series (pure aluminum), the last two digits indicate the minimum aluminum percentage (e.g., 150.x contains at least 99.5% Al). A letter prefix (e.g., A360.0) denotes modifications while age-hardening alloys include a “T” suffix.

Common Applications Table

Applications
Machinery parts, engine blocks, gas meters, gear blocks and cases, fuel pumps, intake manifolds.
Clutch housings, oil pans, motor propellers, pistons, and cylinder liners.

Material Composition and Properties Table

Aspect	Details
Composition	5–22% silicon, with copper, magnesium, zinc, iron, nickel, tin, and manganese as additions.
Microstructure	Silicon particles in an aluminum matrix with an FCC crystal structure.
Silicon Effect	Enhances fluidity for complex mold shapes.
Magnesium Effect	Provides excellent strength and toughness but makes casting challenging.
Manganese Effect	Low-cost option for non-load-bearing applications; poor mechanical properties.

Processing and Manufacturing Properties Table

Aspect	Details
Casting Methods	Sand, permanent mold, pressure die, investment, and plaster casting.
	Advanced methods like rheo-casting and squeeze casting improve dimensional accuracy.
Forming	Molds must account for 3.5–8.5% shrinkage to avoid defects. Complex castings are achievable.
Machining	Machinable but generally inferior to other aluminum alloys.
Heat Treatment	Applicable for copper, copper-magnesium, silicon-magnesium, or zinc-magnesium alloys.
	These alloys can be solution-treated and aged to enhance strength.

Joining and Surface Treatment Table

Aspect	Details
Welding	Most cast alloys are weldable; some require post-weld heat treatment.
	Filler wire selection depends on alloy composition.
Surface Finishing	Yields a smooth finish depending on casting method; suitable for abrasive blasting or acid etching.