How does electrical discharge machining differ from ultrasonic machining in terms of material removal mechanisms and engineering applications? Which of the two processes is suitable for machining of engineering parts made of $\backslash (\backslash$mathrm$\{$Al$\}\_\{2\}\backslash$mathrm$\{$O$\}\_\{3\}\backslash )?$ Give your reasons.

$(7$ marks$)$

What is the name of the machining process as shown in Figure $5?$ Briefly describe the machining process. Is this machining process suited for the following materials: tungsten, pure aluminium, and TiC $?$ Give your reasons.

$(7$ marks$)$

Figure $5$