Manufacturing Processes & Techniques Flashcards
7 cards from real CMS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Manufacturing Processes & Techniques flashcards as text
What is the key advantage of near-net-shape (NNS) manufacturing processes over traditional subtractive methods?
Answer: NNS processes produce parts close to final geometry, minimizing material waste and subsequent machining time
Near-net-shape processes produce parts very close to the final dimensions, significantly reducing material waste (buy-to-fly ratio) and the amount of costly machining required.
In laser beam machining (LBM), the 'heat-affected zone' (HAZ) is minimized by:
Answer: Using short-pulse or ultrashort-pulse lasers that deliver energy faster than heat can diffuse into surrounding material
Ultrashort-pulse lasers (picosecond or femtosecond) deliver energy so rapidly that material is ablated before heat can conduct to surrounding areas, producing minimal HAZ.
In extrusion processes, the 'extrusion ratio' is defined as:
Answer: The ratio of the initial billet cross-sectional area to the final extrudate cross-sectional area
The extrusion ratio (R = A₀/Af) is the ratio of the billet cross-section to the product cross-section, indicating the degree of deformation and influencing required force and grain refinement.
Which surface finishing process uses magnetic fields to hold abrasive particles against a workpiece to achieve very fine surface finishes in inaccessible areas?
Answer: Magnetic abrasive finishing (MAF)
Magnetic abrasive finishing (MAF) uses magnetically controlled flexible abrasive brushes that conform to workpiece surfaces, enabling finishing of complex shapes, inner bores, and micro-components.
In resistance spot welding, the nugget (weld zone) forms primarily at the:
Answer: Faying surface (interface between the two sheets being joined)
Contact resistance is highest at the faying surface (sheet-to-sheet interface), concentrating heat generation there and causing the nugget to form at that location.
What is 'chatter' in machining, and what is the most effective way to eliminate it?
Answer: Chatter is self-excited vibration between tool and workpiece; it is reduced by adjusting spindle speed, increasing system stiffness, or using vibration-damping toolholders
Chatter is regenerative self-excited vibration that produces poor surface finish and tool damage; remedies include spindle speed adjustment to avoid resonance, increased rigidity, and damped toolholders.
In the lost foam casting process, the foam pattern is:
Answer: Left in the mold and vaporized by the molten metal as it fills the cavity
In lost foam casting, the polystyrene foam pattern remains in the unbonded sand mold and is vaporized and displaced by the incoming molten metal, eliminating the need for mold removal steps.