NICKEL ALLOYS STAINLESS STEEL SPACE ROCKETS SPACEX

Back in the Game

Space is hard but nickel makes it possible. The United States of America, through the private company SpaceX, imminently expects to regain its independent way into space.

Although the focus will be on SpaceX, the reality is that all rocket engines of all nations have for the past 60+ years used, and continue to use, nickel superalloys to deliver the power, strength and reliability necessary to achieve orbit. To that, SpaceX is adding durability because of reusability. 

 Official SpaceX Photos
Official SpaceX Photos

The common element, however, is nickel and a group of nickel alloys commonly referred to as Inconel®.

Inconel® is an alloy that is not less than 42% and up to 70% nickel, and with significant chromium and iron components. The many variants – tweaked to meet specific operational requirements – will include small additions of one or more of aluminum, niobium, molybdenum, titanium, aluminum, or cobalt.

The nickel is key.

No element by itself will provide the strength and thermal tolerances that nickel provides.

 Official SpaceX Photos
Official SpaceX Photos

No element by itself will provide the strength and thermal tolerances that nickel provides.

For modern rocket engines the operational temperature ranges are of the greatest interest: ~700C (~1300F) but also great capacity to survive the thermal shock of liquid oxygen and, currently only with SpaceX, but all others in the future, re-ignition in space for a return to Earth.

‘Engine chill’ is frequently referenced prior to engine ignition as the temperature experienced by the engine components (including the ‘bell’ – the nozzle) go from ambient to liquid oxygen (operationally around ~-200C/-300F) to around 3400C (~6000F) in a SpaceX Merlin® engine when operating.

Fortunately the material – especially the engine ‘bell’ – is insulated from this extreme. These conditions are just as true today as it was for the Rocketdyne F-1 engines that powered the Saturn V rockets that launched astronauts from American soil.

Now as then, however, nickel-containing materials are mission critical.

SHARE