Manufacturing Processes and Surface Engineering Flashcards
6 cards from real ME practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Manufacturing Processes and Surface Engineering flashcards as text
In metal casting, porosity defects are primarily caused by:
Answer: Gas entrapment and solidification shrinkage
Porosity in castings arises from dissolved gases released during solidification and from volumetric shrinkage as the metal transitions from liquid to solid.
Hot working of metals is defined as plastic deformation carried out at temperatures:
Answer: Above the recrystallization temperature, so recrystallization occurs concurrently
Hot working occurs above the recrystallization temperature, so new strain-free grains continuously replace deformed grains, preventing strain hardening and allowing large deformations.
In powder metallurgy, sintering after compaction serves to:
Answer: Bond powder particles together and reduce porosity via solid-state diffusion
Sintering heats the powder compact below its melting point, allowing solid-state diffusion to bond particles at contact points and reduce porosity, increasing density and strength.
Which welding process uses a non-consumable tungsten electrode and an inert shielding gas to weld reactive metals like titanium and aluminum?
Answer: Gas Tungsten Arc Welding (GTAW/TIG)
GTAW (TIG welding) uses a non-consumable tungsten electrode with inert gas shielding (Ar or He), providing precise, clean welds ideal for reactive metals and thin materials.
Electroplating deposits a metal coating on a substrate by:
Answer: Electrolytic reduction of metal ions from solution onto the cathode (workpiece)
In electroplating, the workpiece is the cathode; metal ions in the electrolyte are reduced and deposited onto it by passing an electrical current through the solution.
Anodizing of aluminum creates a surface layer of:
Answer: Aluminum oxide (Al2O3) formed by controlled electrochemical oxidation
Anodizing uses electrochemical oxidation in an acidic bath to grow a thick, porous Al2O3 layer on the aluminum surface, improving corrosion and wear resistance.