Answer Happy

Question 4: Q 4A: What is solubility? Write down the general conditions for unlimited solubility? (5) Q 4B: Determine the phases present, the compositions of each phase, and the amount of each phase in wt% for the following NiO-MgO ceramics at 2600°C: (a) NiO 50 mol% MgO; (b) Ni0-65 mol% MgO; (c) Ni0-82 mol% MgO; and (d) Ni0-90 mol% MgO.[See Figure 1). (10) 2800 L 2600 Temperature (°C) 2400 1+S 2200 (Ni, Mgo 2000 NiO 20 40 60 80 MgO Mole percent Mgo Figure 1: Reference Figure for 04B. Q4C: A hypothetical phase diagram is shown in Figure 2. (a) Are any intermetallic compounds present? If so, identify them and determine whether they are stoichiometric or nonstoichiometric. (b) Identify the solid solutions present in the system. Is either material A or B allotropic? Explain. (c) Identify the three-phase reactions by writing down the temperature, the reaction in equation form, and the composition of each phase in the reaction. (10) 1200 L 7+2 1100+ L Ja+L /y+ ß 1L + L₂ 1000 11" 900 800 a+2 1B+L B 700 a+B Temperature (°C) 600 500 B+n @+B 400 300 Q+ @ 200 100 @+n A 20 40 60 80 B