JNTU
JNTU B.Tech II PRODUCTION TECHNOLOGY Previous Question Paper (November/December - 2020 - R13)
Answer any Five Questions. All Questions Carry Equal Marks.
Main
What is a pattern allowance? Explain the types of pattern allowances.
Answer
A pattern allowance is an intentional modification made to the dimensions of a pattern compared to the final casting dimensions. These adjustments compensate for the physical and metallurgical changes that occur during the solidification and cooling of the metal, ensuring the final casting meets the required specifications.
The primary types of pattern allowances are:
- Shrinkage Allowance: Most metals shrink when cooling from liquid to solid state. Patterns are made slightly larger to compensate for this liquid, solidification, and solid contraction.
- Machining (Finish) Allowance: Extra material is added to surfaces that require machining to achieve a smooth surface finish or precise dimensional accuracy after casting.
- Draft (Taper) Allowance: A slight taper is provided on all vertical surfaces of the pattern to allow for its easy removal from the sand mold without damaging the mold walls.
- Distortion (Camber) Allowance: For castings with complex shapes or thin sections, the pattern is intentionally distorted in the opposite direction of the expected warping so that the casting assumes the correct shape upon cooling.
- Shake (Rapping) Allowance: Since the pattern is rapped or vibrated to loosen it from the mold before withdrawal, the mold cavity becomes slightly enlarged. The pattern is made slightly smaller to compensate for this effect.
Enumerate the applications of casting process.
Answer
Casting is a versatile manufacturing process used extensively in various industries. Key applications include:
- Automotive Industry: Production of engine blocks, cylinder heads, pistons, crankshafts, and transmission housings.
- Aerospace: Manufacturing of turbine blades, structural components, and complex engine parts that require high heat resistance.
- Heavy Machinery: Large components such as machine tool bases, gear housings, and heavy-duty frames.
- Infrastructure and Construction: Production of pipes, valves, pump bodies, and manhole covers.
- Consumer Goods: Manufacturing of kitchenware, hardware fittings, and decorative items.
Explain Hot chamber die casting process with a neat sketch.
Answer
Sign in to view the complete answer paper.
Explain the process of Thermit welding with a neat sketch.
Answer
Sign in to view the complete answer paper.
Explain the process of spot welding.
Answer
Sign in to view the complete answer paper.
How is the standard time calculated in a welding process?
Answer
Sign in to view the complete answer paper.
Explain TIG welding process with a neat sketch. Also discuss the advantages, disadvantages and applications.
Answer
Sign in to view the complete answer paper.
Sketch and explain the process of friction welding.
Answer
Sign in to view the complete answer paper.
What are the causes and remedies for the following welding defects? i) Porosity ii) Slag inclusions.
Answer
Sign in to view the complete answer paper.
Derive the expression for driving torque and power in rolling.
Answer
Sign in to view the complete answer paper.
Discuss the defects arise during forging process.
Answer
Sign in to view the complete answer paper.