Material science on ti-ni phase diagram, sketch quantitative free

MATERIAL SCIENCE QUESTIONS;

Q1) A redlich-kister expansion describes the excess free energy of mixing of AL-Pb liquids which have a miscibility gap at lower temperature. The parameters of the expansion are given in the table below where the temperatures dependence is Al+BiT and with the expansion as can be seen from the table extending from zero through second order.

a.Quantitatively plot the depence of the total mixing energy on composition at 1500k

b.From the plot determine the composition of the two liquids at that temperature.

Q3) For the Ti-Ni phase diagram sketch a quantitative free energy at 10500C representing the phase and showing the common tangents that declineate the phase regions. Be sure to label the phase and single and two phase regions on the free energy plot. (make the plot large-fill a page- and draw it carefully so it can be read and I can maximize your credit)

4) For the Ti-O system

a.Plot the 298K energy of formation for all the stoichiometric phases listed in Appendix E of the text as a function of atomic percent oxygen.

b.Draw a Richardson-Ellingham diagram for the Ti-O phases starting, of course with oxidizing the metal to the lowest oxide.

Q5) From the Richardson-Ellingham diagram provided in this exam determine;

a.The oxygen potential at which silicon oxidize to silica at 8000C

b.The oxygen pressure at that point derived from the diagram.

c.The H2/H2O and CO/CO2partial pressure ratios at that point from thediagram.

d.From the diagram identity a metal that will reduce silica (SiO2) to silicon and write the reaction.