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
The heat-affected zone (HAZ) in welding is the region that:
Answer: Was not melted but experienced microstructural changes due to welding heat
The HAZ is the base metal adjacent to the fusion zone that did not melt but whose microstructure and properties were altered by the welding thermal cycle.
Shot peening improves the fatigue life of metal components by:
Answer: Introducing compressive residual stresses in the surface layer that retard fatigue crack initiation and growth
Shot peening bombards the surface with small spherical media, causing localized plastic deformation that induces beneficial compressive residual stresses, which oppose tensile fatigue stresses.
Investment casting (lost-wax casting) is preferred for:
Answer: Near-net-shape production of complex, high-tolerance parts in superalloys and stainless steel
Investment casting uses an expendable wax pattern coated in ceramic to produce intricate, near-net-shape parts with excellent surface finish, suitable for superalloys and aerospace components.
Cold drawing of metal wire through a die produces a product with:
Answer: Increased strength and hardness due to strain hardening, but reduced ductility
Cold drawing at room temperature plastically deforms the wire, increasing dislocation density (strain hardening), which raises strength and hardness while reducing ductility.
Chemical vapor deposition (CVD) is commonly used to apply hard coatings (e.g., TiN, TiC) to cutting tools because:
Answer: It produces dense, adherent coatings with excellent uniformity even on complex geometries at elevated temperatures
CVD deposits hard, wear-resistant ceramic coatings by thermally decomposing gas-phase precursors on the heated tool substrate, producing dense, conformal coatings with strong adhesion.
Extrusion of metals involves:
Answer: Forcing a heated billet through a shaped die orifice by ram pressure to produce a continuous profile
In extrusion, a ram forces a heated metal billet through a shaped die, producing long continuous profiles such as rods, tubes, and complex structural shapes.