working with aluminium
Where precision applications require strong but lightweight materials, aluminium and its alloys are often the metals of choice. It has low density, is non-toxic, has a high thermal conductivity, has excellent corrosion resistance and can be easily cast, machined and formed. It is also non-magnetic and non-sparking. It is both malleable and ductile.
characteristics include:
- Corrosion-resistant: Aluminum forms a thin layer of oxide on its surface that protects it from further oxidation.
- Ductile: it can be manipulated into shape without breaking or losing toughness
- Lightweight: Aluminum is about one-third the density of steel.
- Strong: Aluminum has a high strength-to-weight ratio and can withstand most weather conditions, including extreme temperatures.
- High melting point (349ºC)
- Good conductor: Aluminum conducts heat and electricity well, and its low density allows it to conduct electricity better than other metals.
- Non-toxic: Aluminum is safe for use in products for medical environments and food preparation.
- Impermeable: Aluminum is completely impermeable to light, taste, and aroma.
working with aluminium
Because it is both malleable and ductile while being highly conductive, aluminium can be difficult to work with.
- When machined, aluminium’s ductility causes frictional damage,
- punching can cause it to work harden.
- Laser cutting is inappropriate due to aluminium’s heat reflectiveness
Traditionally, chemical etching isn’t the most attractive technology to use with aluminium either!
Firstly, aluminium is non-corrosive (fundamental to the process) and, secondly, becomes exothermic when it comes into contact with chemical etchants. With that in mind, it stands to reason etching can partially destroy the photoresist that prevents areas of the metal from being machined, affecting precision and quality.
Tecan uses a specific process for etching aluminium which retains its material properties, producing burr- and stress-free parts with smooth edges and no heat-affected zones. Inherently, chemical etching uses low-cost digital tooling so it represents a cost-effective, precise and quicker alternative to traditional methods like laser, stamping and jet cutting.
aluminium alloys
Typically, aluminium is alloyed with copper or zinc:
aluminium- copper alloys
Referred to as aluminium bronzes, these alloys offer strength, wear- and corrosion- resistance as well as improved hardness.
- Strength: Copper content can increase tensile strength and hardness, especially at higher temperatures.
- Hardness: these alloys can be as hard and strong as some steels.
- Corrosion resistance: Copper can help improve corrosion resistance, including against salt water.
- Biostatic effects: Copper can prevent marine organisms from colonising.
- Non-sparking which can help improve safety and longevity
aluminium-zinc alloys
Aluminum zinc alloys have many characteristics, including:
- Strength: high tensile and yield strength
- Corrosion resistance: form a passive layer on the surface that prevents further corrosion in most atmospheric environments
- Excellent thermal conductivity
- Non-sparking which can improve safety and longevity
- Smooth, aesthetically pleasing surface finishes, and can be plated
- Economical
aerospace
Critical aerospace components made from aluminium benefit from inherent significant strength to weight ratio, providing both fuel efficiency and strength. They are also used for engine cooling.
automotive
Strong but lightweight, aluminium contributes significantly to vehicle engine cooling, fuel efficiency and performance – from speaker grilles to sensors, and beyond.
industrial
Aluminium’s corrosion resistance and durability gives parts made with it longevity and reliability. It is also useful for thermal management.
conclusion
Chemical etching from Tecan is a reliable and efficient method for producing intricate, high precision aluminium components. Its versatility and cost-effectiveness make it a valuable technique in various industries, ranging from automotive to aerospace. With its ability to create complex designs and maintain tight tolerances, chemically-etched parts remain a prefererred option for manufacturers seeking quality and precision.
