Aluminum Vacuum Properties, Ultra High Vacuum, UHV

Aluminum: A Better Vacuum Chamber Material

Do more with aluminum: Atlas Technologies is the world leader in the use of aluminum ultra high vacuum systems.  The rugged stainless knife edge of the Atlas Flange welds directly to aluminum chambers.  This allows you to apply the many valuable properties of aluminum and still enjoy rugged demountable sealing.

With the dramatically different physical properties than their stainless steel counterparts, aluminum ultra high vacuum (UHV) chambers are now poised to revolutionize the vacuum industry. These properties when looked at in sum offer compelling physical and cost of ownership advantages over stainless steel.

 

Aluminum Vacuum Properties

•  Aluminum requires less pumping than stainless steel. This is because there is inherently less hydrogen and carbon in aluminum. Furthermore aluminum forms a tenacious oxide that reduces diffusion of vacuum contaminates. Less pumping requires less expensive pumps this translates directly to a lower overall cost when compared to stainless.

•  Reduce cycle time because of fast bake-out and fast pump-down. With 10 x higher thermal conductivity and 21 x the thermal diffusivity, aluminum UHV chambers heat quickly and spread the heat very uniformly. This means aluminum ultra high vacuum systems offer a fast and complete bake-out.

•  Low contamination since aluminum has less carbon and hydrogen than stainless steel. Carbon deposition is a costly problem in ultra high vacuum optics (synchrotron grating, mirror and monochromators) and semiconductor applications. Aluminum has out gassing rates of less than 10 –13 Torr liter/sec cm 2.

•  High vibration dampening, aluminum has a little over 1/3 the Young's modulus of stainless. This means that aluminum UHV chambers will attenuate vibration faster than stainless steel UHV chambers. This makes aluminum a better material for precision synchrotron, semiconductor and physics applications where excess vibration can have disastrous consequences.

•  Aluminum machines 5x faster than stainless Because aluminum chambers can be machined so easily you can have vacuum chamber features actually fit your needs rather than having to modify your needs to fit the chamber. Tell us what you are looking for and we will suggest a design to meet your needs.

•  Aluminum is a lower cost material aluminum is less expensive per unit volume and per pound than stainless. This makes it cheaper to manufacture monocoque style aluminum chambers where many of the chambers support and fixturing components are built-in.

•  Excellent thermal properties, aluminum is excellent heat sink material with 3x greater thermal conductivity. Aluminum is capable of diffusing heat with 21 x the thermal conductivity and has a low thermal emissivity.

•  Compact design reduces costly floor space. Atlas designs aluminum vacuum chambers can that consume 40% less floor space than their stainless counter parts.

•  Light weight because aluminum is 1/3 the weight of stainless steel, less expensive support structure is often required this includes less expensive optical tables…. Aluminum's lighter weight also reduces shipping costs.

•  Can be extruded, elaborate shapes such as complex beam tubes, cooling fins and or modularity can be applied directly to aluminum vacuum ultra high vacuum systems. Contact us for the recommended UHV grade aluminum extruded alloys.

•  Low nuclear activation, Aluminum has a very short neutron activated half life measured in the order of hours, compared to stainless which is measured in many thousands of years. This short half life offers huge disposal savings and immeasurable savings in reduced exposure to staff.

•  Non-magnetic, aluminum is essentially magnetically transparent. With very low magnetic permeability aluminum UHV systems offer very little disruption to electron and ion optics.

•  Chemical resistance, aluminum can be anodized with a hard oxide surface making it chemically resistive to many chemicals.

Low Cost of Ownership for Aluminum UHV

High performance aluminum vacuum systems and using the Atlas Flange TM cost less than stainless steel systems when all costs are considered.

•  Lower over all cost of manufacturing due to compact design and fast machining

•  Smaller pumping requirements due to thermal properties of bake out, reduced out gassing properties of aluminum as well as reduced volume and surface areas

•  Reduced cycle time because of fast bake out and pump down

•  Reduced floor space and support structure due to compact design and light weight

•  Reduced shipping cost because of the light weight and small physical sizes

•  Reduced cost of disposal when nuclear activation is an issue

REFERANCES

THINK IN ALUMINUM