Question

[10 marks] Question 2: A cylindrical specimen of a ceramic material is loaded using the three-point bending mode. Calculate () the minimum possible radius (in mm) of the specimen without fracture; (ii) the flexural modulus where the deflection of the sample is 0.45 mm, assuming that no plastic deformation occurs. Given that the applied load is 460 N, the flexural strength is 113 MPa, and the separation between load points is 50 mm. a) If cupric oxide (CuO) is exposed to reducing atmospheres at elevated temperatures, some of b) the Cu ions will become Cu (i) Under these conditions, name one crystalline defect that you would expect to form in order to maintain charge neutrality. (ii) How many Cu" ions are required for the creation of each defect? (ii) How would you express the chemical formula for this nonstoichiometric material? Clay products forma group of traditional ceramics used for producing pipe, brick, cooking ware, c) and other common products. (i) List the three main components in these clay products. (ii) What role does each component play in the forming and firing procedures? (4+3+3=10 marks)

Answer 1

Answer 3-Poinct bending test APPIe lod 3-POint bendig test Case tlexural stress given ty is FL if craes- sectin is tIR cirelalar) 3 FL (if 262 anod Crass-Section is rectangular) q4estion we mve Cay indrical spesimen So Cross Section is circular S0 R (FL ना we knoro thact Deftection CAY) 12TTRE given L Csepvatin bo load Psins) 5OMM F Cappiied tord 460N Es Flexurat strengh) 13 mPa

1 F Lwe ve to Caluloute Flexural mnluly (E) deflection ts aven AY) = D.45MM fo 3 R= TTR3 ० । 13 x(06x 1T 4.017 X13 4.017mm So rors AY 1211R E So fis E 1aTTR AY KI63 12x 3-14 x (17 xi63)' x (o.45x1 12 20.92 X1 11

cute o2 (if cut exist then FOr fhere is ess Pasitive one charge maintain chege meutrality So In order Pasitive charegc we Must eitter Subtraut egatine OY There to11 be-too Cuit ions Tegutreal For Each of these defeeds For mula Cai 0 -x) earthenware) Stoneware kaolin