Problem1 - Ceramics (attaching table & image under) (a) Today most turbo charged car engines have their rotors made of silicon nitride (Si3N4) rather than the traditional nickel alloy (Figure 1).
i) Justify this material switch from metals to ceramics by comparing FOUR relevant material properties of silicon nitride with that of the previously used Nickel alloy.
[Compare using a “Table” format and Granta-EduPack to find the property values].

ii) Draw a flow chart to outline the main process steps of the Si3N4 ceramic turbo charger rotor manufacture and assembly, and discuss two microstructural features that must be controlled to within strict limits during manufacture.

(b) 20 silicon nitride (Si3N4) samples from the same batch were 3-point bend tested, the results for the fracture strengths are given in Table 1 below.