Wikipedia

Talk:Zerodur

Latest comment: 1 day ago by Elisabeth at SCHOTT in topic Revised Properties Section
Learn more about this page

CTE values

edit
Latest comment: 9 years ago1 comment1 person in discussion

The data presented for the CTE is all over the place. It is present 3 times and is different each time. Can someone come up with a value and make sure it is all correct??

KAW 73.213.29.16 (talk) 16:59, 30 June 2015 (UTC)Reply

edit
Latest comment: 7 years ago1 comment1 person in discussion

Hello fellow Wikipedians,

I have just modified 3 external links on Zerodur. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:

When you have finished reviewing my changes, please set the checked parameter below to true or failed to let others know (documentation at {{Sourcecheck}}).

This message was posted before February 2018. After February 2018, "External links modified" talk page sections are no longer generated or monitored by InternetArchiveBot. No special action is required regarding these talk page notices, other than regular verification using the archive tool instructions below. Editors have permission to delete these "External links modified" talk page sections if they want to de-clutter talk pages, but see the RfC before doing mass systematic removals. This message is updated dynamically through the template {{source check}} (last update: 5 June 2024).

  • If you have discovered URLs which were erroneously considered dead by the bot, you can report them with this tool.
  • If you found an error with any archives or the URLs themselves, you can fix them with this tool.

Cheers.—InternetArchiveBot (Report bug) 11:45, 21 July 2016 (UTC)Reply

New Lead Section

edit
Latest comment: 1 day ago1 comment1 person in discussion

Hi all, I’d like to propose an edit to address the “lead section may need to be rewritten” issue. This new version is more concise, and focuses on what Zerodur is, its main feature, and where it is used. The rest doesn't seem relevant for the lead section to me. The list of specific telescopes could go in the Applications section (I'll follow up on that later), and the last 3 sentences ("Although it has advantages ...") lack a citation, so I've removed them.

Old lead section

Zerodur[1] is a lithium-aluminosilicate glass-ceramic[2] produced by Schott AG since 1968.[3] It has been used for a number of very large telescope mirrors including GTC, Keck I, Keck II,[4] and SOFIA, as well as some smaller telescopes (such as the GREGOR Solar Telescope). With its low coefficient of thermal expansion (CTE), it is suitable for producing mirrors that maintain acceptable figures in extremely cold environments, such as deep space.[5] Although it has advantages for applications requiring a coefficient of thermal expansion less than that of borosilicate glass, it remains very expensive as compared to borosilicate. The tight tolerance on CTE, ±0.007×10−6 K−1, allows for its use in high-precision applications.

References

  1. ^ "Zerodur®". Archived from the original on July 24, 2011. Retrieved September 4, 2011.
  2. ^ Viens, Michael J (April 1990). "Fracture Toughness and Crack Growth of Zerodur" (PDF). NASA Technical Memorandum 4185. NASA. Retrieved 28 August 2011.
  3. ^ "Schott AG Zerodur description". Archived from the original on February 1, 2014.
  4. ^ Döhring, Thorsten; Peter Hartmann; Ralf Jedamzik; Armin Thomas; Frank-Thomas Lentes. "Properties of Zerodur Mirror Blanks for Extremely Large Telescopes" (PDF). Proc. SPIE. SPIE. Retrieved 26 August 2011. (dead link 7 July 2020)
  5. ^ Baer, JW; WP Lotz. "Figure testing of 300 mm Zerodur mirrors at cryogenic temperatures" (PDF). Retrieved 26 August 2011.
New lead section

Zerodur is a lithium-aluminosilicate glass-ceramic manufactured by Schott AG. Zerodur has a near zero coefficient of thermal expansion (CTE), and is used for high-precision applications in telescope optics, microlithography machines and inertial navigation systems.[1][2][3]

References

  1. ^ "Zerodur®". Archived from the original on July 24, 2011. Retrieved September 4, 2011.
  2. ^ Viens, Michael J (April 1990). "Fracture Toughness and Crack Growth of Zerodur" (PDF). NASA Technical Memorandum 4185. NASA. Retrieved 28 August 2011.
  3. ^ "Schott AG Zerodur description". Archived from the original on February 1, 2014.

Thanks for your consideration, and let me know if you have any feedback! Elisabeth at SCHOTT (talk) 12:25, 10 July 2024 (UTC)Reply

Revised Properties Section

edit
Latest comment: 1 day ago2 comments1 person in discussion

Hi all, I’d like to propose some changes to address the “written like an advertisement” issue. I am not entirely sure what the user's issue with the article was, but I presume it is refering to some "better than" comparsions to other materials and products, mentioned in the Properties section. To improve the neutrality of the article, I'm proposing a version that removes those superiority claims. Thanks for taking a look at this proposal, and let me know if you have any input or other thoughts! Elisabeth at SCHOTT (talk) 12:40, 10 July 2024 (UTC)Reply

−
== Properties ==

Zerodur has both an [[amorphous]] (vitreous) component and a [[crystalline]] component. Its most important properties are: * The material exhibits a particularly low thermal expansion, with a mean value of 0 ± 0.007×10<sup>−6</sup> K<sup>−1</sup> within the temperature range of 0 to 50 °C. This thermal expansion performance is comparatively superior to [[Fused quartz#List of physical properties|that of fused quartz]] by two orders of magnitude. * High 3D [[Homogeneity (physics)|homogeneity]] with few inclusions, bubbles and internal stria (as contrasted to [[Cer-Vit]]). * Hardness similar to that of [[borosilicate glass]], so that it can be ground and polished more easily than [[fused quartz]]. * High affinity for [[Optical coating|coatings]]. * Low [[helium]] permeability. * Non-porous (as contrasted to [[sintered]] ceramics). * Good chemical stability similar to that of [[fused quartz]].

* [[Fracture toughness]] approximately 0.9 MPa·m<sup>1/2</sup>.
+
== Properties ==

Zerodur has both an [[amorphous]] (vitreous) component and a [[crystalline]] component. Its most important properties are: * The material exhibits a particularly low thermal expansion, with a mean value of 0 ± 0.007×10<sup>−6</sup> K<sup>−1</sup> within the temperature range of 0 to 50 °C. * High 3D [[Homogeneity (physics)|homogeneity]] with few inclusions, bubbles and internal stria. * Hardness similar to that of [[borosilicate glass]]. * High affinity for [[Optical coating|coatings]]. * Low [[helium]] permeability. * Non-porous. * Good chemical stability.

* [[Fracture toughness]] approximately 0.9 MPa·m<sup>1/2</sup>.

Elisabeth at SCHOTT (talk) 12:40, 10 July 2024 (UTC)Reply

  1. ^ a b "ZERODUR® Extremely Low Expansion Glass Ceramic: SCHOTT Advanced Optics - SCHOTT AG". www.schott.com. Retrieved 15 April 2018.
  2. ^ "SCHOTT CTE Grades". Archived from the original on October 4, 2013.
  3. ^ a b c d [1][dead link]
  4. ^ a b Cite error: The named reference Viens1 was invoked but never defined (see the help page).
  5. ^ a b Hartmann, P. (18 December 2012). "ZERODUR - Deterministic Approach for Strength Design" (PDF). Optical Engineering. 51 (12). NASA: 124002. Bibcode:2012OptEn..51l4002H. doi:10.1117/1.OE.51.12.124002. S2CID 120843972. Retrieved 11 September 2013.
  6. ^ "SCHOTT CTE Grades". Archived from the original on October 4, 2013.
Add topic
Retrieved from "https://en.wikipedia.org/w/index.php?title=Talk:Zerodur&oldid=1233698773"