Q.1. Metal alloys are commonly used in hard tissue applications. Below is some representative diffusion data for different atoms in two alloys labelled A and B. All the values of D are calculated at body temperature 37 C (310 K). Alloy A B Hydrogen Do in m/s 1.30 x 10-6 1.15 x 106 Eo in eV 0.15 Din m/s 7.36 x 10-12 Carbon Do in m/s 1.05 x 10-6 Eo in eV 0.28 Din m/s 1.18 x 10-11 1.24 x 10-15 Self Do in m/s 6.15 x 10-5 Eo in eV 0.77 1.03 Din m/s 1.57 x 10-21 a) Complete the table by filling in the blanks. (3 marks) b) How far would hydrogen diffuse in, respectively, alloy A and alloy B over the expected 15 year lifespan of a bone replacement material? (2 marks) c) One of the alloys is close packed (either FCC or HCP) while the other is not. Which do you think is close packed and why? (1 mark)