The authoritative public forum
  for Metal Finishing since 1989
-----

Alloy selection for university rocket project

October 10, 2009

I have been tasked with the job of selecting two suitable alloys for a University rocket project.

The first alloy is for the tanking, the second is for the main combustion chamber of the rocket engine. To complicate matters, the vehicle is intended to be reused many times and at the end of each flight will land in the Ocean, so both structures need to be salt-water resistant due to the recovery method.

For the tanking structure we require a material which allows the safe storage of cryogenic Liquid Hydrogen at a temperature of -427 degrees Fahrenheit (-255 °C). The tank will experience some heating during the flight, so the material also needs to have good structural properties when experiencing swift temperature changes.

For the main combustion chamber, this will be a high-temperature, high-pressure environment, but ease of manufacturing is going to be the key driving factor.

The weight of the materials in both elements is not actually of very significant concern for this particular design as it will have a wealth of surplus performance anyway, so we can afford a relatively "heavy metal" approach to the entire design. Some flavor of high-nickel Steel is where we ave already been looking, but I'm not sure which specific materials I should be looking for.

I would appreciate any recommendations for where to start researching.

Jay Sheridan
Student - Cape Canaveral, FL, USA

---

Shuttle SRB engine nozzles are made from D6AC steel, 1.165cm thk.

James Totter, CEF
- Tallahassee, Florida
October 12, 2009