Talk:Phase diagram
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Don't chemists use the term phase diagram for the P-T diagrams showing the lines of equilibium (and the triple point) between eg solid, liquid and gas phases of a pure substance? Linuxlad 22:54, 18 Feb 2005 (UTC)
I have written two lines here on the physico-chemical use. I would prefer that this thermodynamical aspect was associated with 'phase diagram' and that the space of dynamical variables was called 'phase space' (phase space currently redirects here). We already have stuff being added to Liouville's theorem (Hamiltonian) which better belongs in a phase space article IMHO Linuxlad 12:33, 19 Feb 2005 (UTC)
Iron/Carbon system - I've written to Longman's to ask if the phase diagram quoted by W J Moore (in 'Physical Chemistry' fig 5.24 IIRC) is useable.Linuxlad 14:28, 26 Mar 2005 (UTC)
- I now have permission from Pearson to include this. Linuxlad 22:00, 23 May 2005 (UTC)
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[edit] More diagrams
I think we should add a stie that have more than allows. Like ammonia, nitrogen and such
- I have discussed and added a binary boiling point diagram to this article. I think it would be a good idea also to add the following for a single (pure) component:
Temperature vs. specific volume diagram with isobars showing constant pressure
- A 3D diagram of Pressure (P), specific volume (v), and Temperature (T). I will modify one from the French Wikipedia and insert it into this article.
- This is helpful when covering equation of state relating P, v, and T.
- Temperature vs. specific entropy diagram with isobars showing constant pressure
- This is helpful for explaining Refrigeration cycle, Carnot cycle, and Rankine cycle.
- H Padleckas 06:55, 11 August 2007 (UTC)
[edit] Phase Diagram ≠ Binary Phase Diagram
When people talk about phase diagrams they usually mean Pressure on the ordinate, T on the abscissa, for one particular material. When talking about binary phase diagrams, two different materials (usually pure metals) are mixed on a continuum in the abscissa, with T on the ordinate. Currently Binary phase diagram links to this page, when it actually needs its own. Riceplaytexas 07:09, 13 January 2007 (UTC)
- I disagree with you on this point. In my experience, people use "Phase diagram" about both P-T diagrams, binary and ternary phase diagrams. This is just my personal experience though, it may be that it is different from field to field, university to university, or country to country. Dr bab 07:51, 25 April 2007 (UTC)
I've reset some of the redirects to the binary phase diagram sectionRiceplaytexas 07:28, 13 January 2007 (UTC)
[edit] Ternary phase diagrams
This article needs something on the ternary diagrams as well. I will start to look into it. However, it is difficult to explain 3D diagrams without good figures. Anyone have any good figures that are free to use? Dr bab 08:24, 25 April 2007 (UTC)
- I once tried to make a raster picture of a 2D triangular base for a ternary diagram. It did not come out looking very good, and I did not finish it. One of these years when I feel really ambitious, I may try to make a ternary composition 2D triangular base again using Inkscape to make it in an *.svg format. H Padleckas 23:41, 11 August 2007 (UTC)
- I was finally able to make a better *.png image of the 2D triangular base mentioned above, which I sent to Pckilgore by private e-mail. Based on that, he made the *.svg diagram shown below. H Padleckas (talk) 11:49, 25 November 2007 (UTC)
- A draft for the section:
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- With three components present, it is common to display the composition on a triangle ABC, and then use an axis perpendicular to this triangle for an external variable, such as temperature or pressure. The composition at the corners of the triangle corresponds to the pure A, B and C components. Along the three edges, composition varies from pure A to pure B, from pure B to pure C and from pure C to pure B. All lines that are parallel to the A-B edge of the triangle represent a constant composition with respect to C. Likewise, the fractions of A and B are constant on lines parallel to the BC and AC lines respectively.
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- When more than two components are considered, the number of dimensions makes the graphical representation difficult. Either, a three dimensional diagram must be drawn, or one variable must be kept constant. It is common to draw ternary phase diagrams at a constant temperature and pressure, in order to be able to draw a two-dimensional diagram. Such a diagram will show how the phases of the system changes with composition at a given temperature and pressure. —The preceding unsigned comment was added by Dr bab (talk • contribs) 14:03, 25 April 2007 (UTC).
Ccwillis 07:47, 7 August 2007 (UTC)Except the isothermal or isobaric section with fixxed temperature and pressure, there is another section called vertical section or isopleth, at which the fraction of one component or the content ratio of two components is fixxed,while the temperature or pressure is variable.
I feel a discussion of nodes, the plait point, and tie lines of a three component ternary phase diagram is also relevant, considering a surprising lack of information available on the internet and even in textbooks. I'll try to put something together when I have some free time but feel free to beat me to the punch. What should be fairly easy is a 2D triangular base, I can make a svg version and upload for others to play with. Pckilgore 03:50, 7 November 2007 (UTC)
--Pckilgore 04:57, 7 November 2007 (UTC)
- Pckilgore,
I see a flaw in your diagram above. I also have other suggestionscorrected. We can work together to develop these diagrams. Please see a message I left on your talk page. H Padleckas 04:24, 14 November 2007 (UTC)
[edit] Pxy Phase Diagram
Hi can someone help me with Pxy diagram. Is the pressure axis referring to total pressure or the partial pressure of the components? Thanks
