Tango Posted January 1, 2009 Report Share Posted January 1, 2009 As it says in the title Got a outcome to finnish but havent a clue what this diagram means plus notes dont solve this.This is the question need to answer,Describe what is happening to the material at these points.X -E - B - D - F -Any Help is welcomed Quote Link to comment Share on other sites More sharing options...
TonyB Posted January 1, 2009 Report Share Posted January 1, 2009 As it says in the title Got a outcome to finnish but havent a clue what this diagram means plus notes dont solve this.This is the question need to answer,Describe what is happening to the material at these points.X -E - B - D - F -Any Help is welcomed Scratching back through my memory - the diagram describes the state of the metal for a given temperature and composition. At X the lead/tin mixture is starting to solidify (as it cools). Basically follow the dotted line downwards (as the metal cools) and the metal become more and more solid until it hits line B-E where it is all solid (it doesn't all solidify at once, which is what the diagram is showing). The proportion of each of the constituents decides at what temperature these two things happen. Below the solidification line the temperature and composition will decide what structure the material forms (face centred cubic, body centred cubic etc). I'm more familiar with the iron state diagram and lead tin but the principles are the same.A represents the melting point of 100% leadE represents the temperature where solid lead/tin melts to liquid without going through a transition stage (like partial melting to form a paste). This only happens for lead/tin with the composition shown on the diagram, all others go through the paste stage. This point has a specific name but I can't remember it off hand.Googe `lead tin state diagram'Good luck. Quote Link to comment Share on other sites More sharing options...
Tango Posted January 1, 2009 Author Report Share Posted January 1, 2009 Thats given me enough to get it done i think ye i will google to find the exact names of the points thanks for the help Quote Link to comment Share on other sites More sharing options...
TonyB Posted January 1, 2009 Report Share Posted January 1, 2009 I think point E is the eutectic or eutectoid point...maybe. I'm better with steam thermodynamics to be honest. haven't looked at materials science since college days (and that was a fair long time ago). Quote Link to comment Share on other sites More sharing options...
PaRtZ Posted January 1, 2009 Report Share Posted January 1, 2009 Point E is indeed a eutectic point. Its the point which the liquid part touches the solid part.Point X is the point at which when cooling the uniform liquid down, substance alpha starts to form as well. I have a feeling that may not be your answer though. Point D is the melting point of pure tin, SnNow I dont know if these are your correct answers, butPoint B is a hypoeutectoidPoint F is a hypereutetctoidAnd they're based solely on the composition of the alloy and not of the temparature (which obviously stays constant)Sorry if thats useless though! Quote Link to comment Share on other sites More sharing options...
Tango Posted January 2, 2009 Author Report Share Posted January 2, 2009 That sounds familiar great help lads time to hand this in and get my HND so I can go offshore. Sometimes I wonder why they put this into a electrical engineering course lol. Quote Link to comment Share on other sites More sharing options...
Bionic Balls Posted January 2, 2009 Report Share Posted January 2, 2009 (edited) think they've covered most of that...for the record...you were calling all "materials scientists" ok and it's a "phase digram"- that'll get you more hits on google! any help just ask..adamedit: Now I dont know if these are your correct answers, butPoint B is a hypoeutectoidPoint F is a hypereutetctoidtrue but...that's not unique to these points- they're solubility limits.Lastly- that's looks to me like you have to describe the cooling sequence of composition X...maybe referring to the other points? Are you sure you read the question properly? Edited January 2, 2009 by Bionic Balls Quote Link to comment Share on other sites More sharing options...
Tango Posted January 2, 2009 Author Report Share Posted January 2, 2009 The questions says to say what the material is doing at that point basicly to explain what is solid liquid or paste and whats temp and % of the propertys of the material. If you get what I mean I think they were asking for those nice long words partz said I seem to remeber the guy going on about that it was over a year ago you see >.< Quote Link to comment Share on other sites More sharing options...
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