spaceTribometer2010 - Tribol Lett DOI...

Info icon This preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
UNCORRECTED PROOF ORIGINAL PAPER 1 2 Space Tribometers: Design for Exposed Experiments on Orbit 3 Brandon A. Krick W. Gregory Sawyer 4 Received: 24 February 2010 / Accepted: 18 August 2010 5 Ó Springer Science+Business Media, LLC 2010 6 Abstract Eight pin-on-disk tribometers have been made 7 for testing materials in space on board the International 8 Space Station. They will be exposed directly to the low 9 earth orbit (LEO) environment on board the ‘‘Materials on 10 the International Space Station Experiments’’ platform 11 where they will be exposed to extreme conditions including 12 atomic oxygen, ultrahigh vacuum, radiation (including UV 13 radiation), and thermal ranges from - 40 to 60 ° C. In order 14 to survive launch and the LEO, these tribometers were 15 designed to be extremely compact, rugged, and reliable. 16 Pin-on-disk tribology experiments are now being per- 17 formed with a 13.2 mm/s sliding velocity (14 RPM at 18 9 mm wear track radius) and a 1 N normal load with 19 hemispherical pin of 1.5875 mm radius. Materials tested 20 include MoS 2 /Sb 2 O 3 /Au, MoS 2 /Sb 2 O 3 /C, YSZ/Au/MoS 2 / 21 DLC, and SiO-doped DLC coatings, and bulk samples of 22 polytetrafluoroethylene (PTFE) alumina nanocomposites 23 and gold. 24 25 Keywords Space tribology ± Tribometers ± Aerospace ± 26 Coating ± Solid lubricants ± Low earth orbit 27 1 Introduction 28 Existing and future moving mechanical assemblies for 29 aerospace applications depend upon the maintenance free, 30 low friction, and low wear operation of solid lubricants and 31 coatings of contacting surfaces. The space environment is 32 harsh, with a wide range of thermal extremes, ultrahigh 33 vacuum, atomic oxygen, solar radiation (including 34 destructive ultraviolet radiation), and micro meteoroids; 35 this was recently reviewed in the January 2010 MRS 36 Bulletin [ 1 ]. These environmental conditions collude to 37 make most traditional lubrication strategies and intuitions 38 gained from terrestrial tribology dubious. There remains a 39 desire to better understand the effects of the space envi- 40 ronment on materials and the tribological behavior of 41 materials in that environment. 42 Historically, the observations of material degradation as 43 observed on returning spacecraft motivated the studies of 44 the space environment and its deleterious effects on most 45 materials. Over the past half-decade many exposure and 46 flight experiments have been devoted to understand this 47 space environment and explore the possibility of terrestrial 48 laboratory recreation of these conditions. One of the first 49 extensive materials exposure experiments in space was 50 NASA’s Long Duration Exposure Facility (LDEF). Since 51 then, there have been a number of exposure experiments 52 including experiments from the European Space Agency 53 (ESA), Japan Aerospace Exploration Agency (JAXA), and 54 the National Aeronautics and Space Agency (NASA) 55 (recently reviewed by Edwards [ 2 ]).
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern