Talk:Shape-memory alloy

Untitled

The data in this page has been transferred from the Memory metal article (apologies if this was the wrong way to move them). The original author info is still stored under the memory metal history. Average Earthman 11:05, 9 Dec 2004 (UTC)

Plot...

I believe the plot of the martensite/austenite ratio dependence on temperature is wrong. I agree that a similar plot can be obtained by plotting deformation versus temperature, when an SMA actuator work against eg. a constant load. In that case the backslash can easily be explained by the deformation treshold. I make this claim, because I made several measurement of resitance and radiation heat, and data suggust that the relation is semidefinit.

2009-07-30, zyrill: The plot is, as far as I can tell, correct. This is exactly the same plot that I have been taught in advanced materials lectures in Darmstadt Technical University, Germany...

The crystal structure formed depends on the temperature and the stress state placed on the metal. The plot shows that cooling shape memory alloy will cause martensite to form and heating causes austenite to form, which is correct.Routy (talk) 21:25, 6 December 2009 (UTC)

Manufacture and Uses

Where have the sections gone, there appear just to be 3 titles but with nothign underneath them. has the page been vanadalized or something similar?

Are Raychem the pioneers in this field

In an interview with Paul Cook (Harvard business review March-April 1990) Paul Cook of Raychem claimed that the Naval Ordinance Lab had begun the research and that Raychem developed the heat shrinkable plastics. Back in 1970. Page 105 HBR March - April 1990.

PS. Raychem was acquired by Tyco

Kendirangu 08:44, 25 November 2006 (UTC)

Can somebody fix the first line of this article please, I can't seem to do it, but you know what I'm talking about.

I think this page needs to be cleaned up a bit in terms of understandable language. Its first paragraph is confusing in its language. 66.16.162.134 14:48, 18 December 2006 (UTC)

Manufacture section?

Doesn't make sense, particularly the part about 500 degrees for more than 5 minutes, which seems to contradict the previous line. Very bare paragraph that doesnt seem necessary. Also I think the medical applications could be talked up a bit more seeing as thats where most of the revenue will come from. Clot filters, stents, guidewires, and why they are suited to these applications. I would do it, but I just don't have the time, and when I do, I won't have the internet :( Howboutpete 02:18, 30 May 2007 (UTC)

Shape memory coupling

Could someone have a glance at Wikipedia:Articles for deletion/Shape memory coupling? New article: disussion ongoing on what to do with it. Gordonofcartoon 00:15, 17 July 2007 (UTC)

Revolutionised fiber optic development?

I'm wondering whether there is any reference for this claim and, if there is, whether it would be better to have a more complete discussion of the fiber optic applications in a separate paragraph rather than having it in the middle of a paragraph discussing medical applications. Moriquendi-101 21:22, 28 July 2007 (UTC)

SMAs without undergoing a martensite transformation

The articles should be updated to include shape memory alloys of FeGa and FeAl. Both materials show a pseudoelastic properties, while both do not undergo a martensitic transformation. In this case the pseudoelastic property is due to " Superpartial dislocations with Burgers vector of 1/4[1 1 1] were pulled back by nearest-neighbour and next-nearest-neighbour antiphase bound- aries during unloading," according Yasuda et al. As a result this conflicts with the general statement in the article, "These extraordinary properties are due to a temperature-dependent martensitic phase transformation from a low-symmetry to a highly symmetric crystallographic structure. Those crystal structures are known as martensite (at lower temperatures) and austenite (at higher temperatures)." The addition of the word generally to the statment will improve the articles accuracy. An additional paragraph in the body of the article will be helpful as well. A good reference for these changes could be based on the published article, H.Y. Yasuda, M. Aoki, A. Takaoka, Y. Umakoshi. Pseudoelasticity in Fe3Ga single crystals. Scripta Materialia 53 (2005) 253–257 —Preceding unsigned comment added by 129.22.154.228 (talk) 00:34, 23 October 2007 (UTC)

1-way vs. 2-way Schematic

The One-way vs. two-way Shape Memory Schematic is not very clear. I stared at it for a minute without really understanding it. 71.231.179.83 (talk) 06:20, 3 March 2008 (UTC)

I went to this page in the hope of understanding how shape memory alloys work but ended up none the wiser🙁. The video was really not very helpful, but perhaps at quarter speed it might be. Then I found an excellent explanation at https://www.youtube.com/watch?v=wI-qAxKJoSU. A prominent link should be included in the article I suggest, and also a more detailed explanation of twinning. The video differs from the picture shown here in that lines are used to make the shapes and their changes more apparent. Can someone add it to the list of references?

Someone gave me one of these nitinol springs at a conference and it is interesting that just breathing hot air over the spring is enough to make it resume its original size — no special equipment needed at all! This can't be mentioned in the article of course as there is no published reference. --Brian Josephson (talk) 08:16, 9 July 2024 (UTC)

Section on Martensite

I think the section on Martensite could be ommitted from this article, seeing as there is a direct copy of the information contained in a link available from this very article.Routy (talk) 13:51, 4 March 2008 (UTC)

I agree. Go ahead and do it. Tanthalas39 (talk) 23:24, 8 March 2008 (UTC)

Section removed. Could do with further tidying —Preceding unsigned comment added by Routy (talk • contribs) 12:06, 3 April 2008 (UTC)

Trademarks

Judging from the typography on the Jameco website, "Muscle Wire" and "Flexinol" are trademarks. Unfree (talk) 13:06, 2 April 2008 (UTC)

Overview

The first paragraph is difficult to understand sbandrews (t) 13:56, 26 April 2008 (UTC)

I agree. It doesn't actually say anything... How about this:

A shape memory alloy (SMA, also known as a smart alloy, memory metal, or muscle wire) is an alloy that "remembers" its shape. A shape memory alloy can be deformed and then when heated to a specific temperature returns to its original shape.

I know its not much of a change but it at least it qualifies '"remembers" its shape' in a more useful way. --**CatoftheNight** (talk) 11:19, 12 May 2008 (UTC)

Overview Section: One of the bloodiest country??

One of the bloodiest country is America. Because it steals talent n technology from other country and put them in its name.

I'm not sure what this means, how it relates to the article, nor why it is in the "Overview" section. 69.9.146.66 (talk) 14:05, 16 October 2008 (UTC)

History

William Buehler objects to the discovery being referred to as an accident - see his oral history on the discovery at http://www.wolaa.org/files/Nitinol_Oral_History.pdf Pinhead69 (talk) 11:54, 2 December 2008 (UTC)

Work

As it is used for robotic actuators, what about the amount of work that the material can do? I have a sample of the material and it seems a rather weak force. —Preceding unsigned comment added by 85.150.220.83 (talk) 11:32, 26 December 2008 (UTC)

References

This page is full of facts and has hardly any referrences to check them. I'm not a subject matter expert at all and I have no idea where to look for these references, so would somebody that can find the right references add them please?     — SkyLined (talk) 11:34, 7 September 2009 (UTC)

The problem with shape memory alloy research is that most of the information on SMA is either very "wooly" without many hard facts, or acurate but really hard core. I'll try and find some good references, most of the sections on here are correct.Routy (talk) 21:30, 6 December 2009 (UTC)

Austenite

I can understand martensitic transformation happening, but isn't austenite purely a phase of iron-carbon? --Lead holder (talk) 12:29, 16 April 2014 (UTC)

Conflict-of-interest reference removal

Hi, in this edit I have just removed a reference added by a user with a conflict of interest. I do not judge of the quality of the reference. If it is a valuable addition to the article, then a more experienced user can perhaps add it back. Thanks, Ariadacapo (talk) 10:10, 2 September 2015 (UTC)

OGG file no play

Does not play on my Moto G22 (about 2 years old) Bards (talk) 22:15, 24 January 2023 (UTC)

Plots with legends or labels wrong

In accordance with the text the large plot of % Mertensite vs. temperature defines A_f, M_s and M_f. I believe in the images in the one-way/two-way sections the legends, or labels are wrong. They specify the temperature to go from A_f down to T₁ (a little less than M_s), when the shape-memory effect is supposed to emerge. However, in this situation the material is almost completely austenitic, where shape-memory should not show up. I believe the instances of M_s in that diagram need to be replaced by M_f, for the material to be martensitic. Can some expert please review and change the image, if I'm correct? While on the task, maybe also the unexplained superscripts of 0 can be either explained or removed. WikiPidi (talk) 18:57, 4 November 2024 (UTC)