Ultra pure aluminum (Al)

Specification of Ultra‑Pure Aluminum (Al)

Material: Ultra‑Pure Aluminum (Aluminium)
CAS Number: 7429‑90‑5
Purity Grades:

• ≥ 99.99% (4 N) – typical high‑purity industrial aluminium

• ≥ 99.999% (5 N) – ultra‑pure aluminium with total impurities <10 ppm

• ≥ 99.9999% (6 N) or higher – specialized research/MBE grade aluminium

Typical Physical Properties:

• Density: ~2.70 g/cm³ at 25 °C

• Melting Point: 660.37 °C

• Thermal Conductivity: Highest among common metals (improved further at ultra‑purity)

• Electrical Resistivity: ~2.65 µΩ‑cm (for ultra‑pure grades)

Impurity Limits / Typical Composition for High‑Purity Grades:

• Total targeted impurities: <50 ppm typical for 5 N grade; <10 ppm for 6 N grade

• Trace elements such as Fe, Si, Cu, Zn, Ga are minimized according to supplier spec.

Delivery Forms / Sizes:

• Bars, blocks, rods, foils, strips, wires — depending on application (e.g., sputtering targets, vacuum deposition, electronics).

• Custom dimensions and machining available for ultra‑pure applications.

Packaging & Storage:

• Vacuum‑sealed or inert‑gas purged packaging recommended to maintain ultra‑purity and avoid surface contamination.

• Stored in clean and dry environment; machining and handling under controlled atmosphere preferred for 5N+ or 6N+ grades.

Key Notes for Buyers

• Ultra‑pure aluminium (≥ 99.999%) delivers exceptional electrical and thermal conductivity, superior corrosion resistance, and enhanced performance in electronics, optics, and high‑tech manufacturing.

• The “N” notation (4N, 5N, 6N) refers to number of nines in the purity generally: 99.99% = 4N, 99.999% = 5N, etc.

• The cost and complexity of refining aluminium increase significantly for ultra‑purity grades (5N–6N), due to advanced purification methods like zone refining, fractional crystallization, or triple‑layer electrolysis.

• For applications such as thin film deposition, sputtering targets, vacuum electronics, or semiconductor components, even minimal impurities can have large effects on performance (e.g., contamination, defects). Choosing the correct purity grade and ensuring proper handling are critical.

Advantages of Ultra‑Pure Aluminum (Al)

• Ultra‑pure aluminum embodies a rare combination of high electrical and thermal conductivity, exceptional corrosion resistance, and minimal impurity content — making it a preferred material for demanding applications in electronics, optics, aerospace, and high‑performance structural systems.

• One of the standout advantages of ultra‑pure aluminum is its exceptional electrical and thermal performance. With impurity levels reduced to just a few parts per million, the metal’s conductivity improves significantly, which is critical in high‑technology environments such as semiconductor interconnects, sputtering targets, and vacuum deposition systems. Equally, its outstanding thermal conductivity supports efficient heat dissipation in compact electronics, high‑power modules, and advanced cooling systems.

• Beyond functional performance, ultra‑pure aluminum offers superior corrosion resistance and surface durability. The near‑absence of alloying elements means the material retains its ability to form a stable, self‑healing oxide layer, providing excellent protection against environmental attack. This makes it ideal for use in harsh or corrosive environments, whether as a structural component, a coating substrate, or as a high‑reflectivity surface.

• From a processing and manufacturing standpoint, ultra‑pure aluminum facilitates precise fabrication and high‑quality finishes. With minimal inclusion of impurity phases and a uniform grain structure, machining, forming, and deposition operations produce better repeatability and fewer defects. This reliability is especially valued in optics (mirror coatings), vacuum systems (sputter targets), and superconducting applications where even trace impurities or defects can compromise performance.

• In summary, ultra‑pure aluminum provides a high‑performance base metal for applications where conductivity, corrosion resilience, material purity, and fabrication precision converge. Whether used in microelectronics, aerospace engineering, or advanced optics, it delivers a strategic material advantage for engineers and manufacturers seeking reliable performance in demanding environments.