Explain the investment casting process and its advantages.

Investment casting (lost wax process) involves: Creating wax patterns, Assembling patterns on a tree, Building ceramic shell through repeated dipping and stuccoing, Dewaxing (autoclave or flash fire), Firing shell to strengthen, Pouring molten metal, Breaking shell and finishing. Advantages: Excellent surface finish (Ra 1.6-3.2 micrometers), Tight tolerances (+/-0.1%), Complex geometries and thin walls, Wide material range, Near-net-shape reducing machining. Used for turbine blades, medical implants, jewelry, and aerospace components where precision and material properties justify higher cost.