ME-305 Manufacturing Process - Dec 2024 Question Paper

Under each question, How to answer lists the points an answer should cover, outlined by CampusPrep from the syllabus. Check the details against your textbook.

1. 7 Marks
   aAnalyze the properties of foundry core sands and their impact on casting quality.
   How to answer

   • Essential properties of core sand: green strength, dry strength, permeability, refractoriness, collapsibility
   • Core binders and additives used to achieve desired properties
   • Direct impact of core properties on casting defects (blowholes, veins, dimensional inaccuracies, hot tears)
2. 7 Marks
   bDiscuss the significance of solidification, defects, and their elimination in the casting process.
   How to answer

   • Solidification mechanism: nucleation and grain growth, Chvorinov's rule
   • Significance of directional solidification and riser design to prevent shrinkage cavities
   • Major casting defects: porosity, shrinkage, hot tears, cold shuts
   • Techniques for elimination: proper gating/risering, venting, temperature control, chills
3. 7 Marks
   aCompare the characteristics of AC and DC welding machines and their influence on welding outcomes.
   How to answer

   • Comparison table: power source, cost, efficiency, polarity control, arc blow
   • Heat distribution in AC (50-50) vs DC (DCEN vs DCEP)
   • Influence on weld outcomes: penetration depth, spatter, bead profile, suitability for thin/thick sections
4. 7 Marks
   bEvaluate the advantages and limitations of TIG and MIG welding compared to traditional methods.
   How to answer

   • Working principles of TIG and MIG welding
   • Advantages over traditional methods: cleaner welds, no slag removal, superior control, high deposition (MIG), versatile thin gauge welding (TIG)
   • Limitations: high equipment cost, inert gas expense, sensitive to wind/outdoor environments, high operator skill required
5. 7 Marks
   aDiscuss the importance of pattern design considerations and core boxes in pattern making.
   How to answer

   • Pattern design factors: parting line selection, gating placement, surface finish
   • Pattern allowances: shrinkage, draft, machining, distortion, shaking
   • Role and importance of core boxes: producing accurate cores for hollow shapes, types of core boxes (half, dump, split, gang)
6. 7 Marks
   bExplain the different types of patterns and their specific uses in casting.
   How to answer

   • Classification of patterns: single piece, two-piece/split, match plate, gated, sweep, skeleton, loose piece
   • Working and specific manufacturing applications of each pattern type
   • Selection criteria based on production volume, size, and complexity of casting
7. 7 Marks
   aDescribe the types of forging operations and their applications in manufacturing.
   How to answer

   • Basic forging operations: upsetting, drawing out, fullering, edging, bending, punching, drifting
   • Open-die vs closed-die (impression-die) forging operations
   • Industrial applications: crankshafts, connecting rods, gears, turbine disks, hand tools
8. 7 Marks
   bAnalyze the role of forging machines in the production process.
   How to answer

   • Classification of forging equipment: impact hammers (gravity drop, power drop, counterblow) vs presses (mechanical, hydraulic, screw)
   • Kinematics and energy delivery mechanisms (impact load vs sustained pressure)
   • Role in productivity, dimensional accuracy, grain flow orientation, and structural integrity of components
9. 7 Marks
   aExplain the operation of hydraulic and pneumatic presses in manufacturing.
   How to answer

   • Working principle of hydraulic press based on Pascal's law; components: cylinder, ram, hydraulic fluid, control valves
   • Working principle of pneumatic press using compressed air; rapid cycling and quick response
   • Comparison of load capacity, stroke speed, control flexibility, and typical industrial use-cases
10. 7 Marks
    bDiscuss the demonstration of piercing, slitting and deep drawing operations on press machines.
    How to answer

    • Piercing: process definition, punch-die clearance, cutting action producing an internal hole with punch slug as scrap
    • Slitting: shearing process with rotary knives or straight shearing without scrap generation
    • Deep drawing: conversion of flat sheet metal blank into cup-shaped component, role of punch, die, and blank holder force to prevent wrinkling
11. 7 Marks
    aOutline the process of shearing, punching, piercing, blanking and trimming in press working.
    How to answer

    • Mechanics of shearing: plastic deformation, penetration, and fracture
    • Punching vs Blanking: defined by whether the cut piece (blank) or the sheet with the hole is the useful part
    • Piercing: hole creation without slug or standard hole cutting
    • Trimming: cutting away excess scrap/flash from the perimeter of a drawn or forged part
12. 7 Marks
    bDiscuss the importance of tool dies, auxiliary equipment and safety devices in press working.
    How to answer

    • Tool dies: design precision, die set components (die block, punch plate, stripper, guide pins), role in part geometry
    • Auxiliary equipment: lubricators, uncoilers, levelers, ejectors, scrap winders
    • Safety devices: two-hand controls, light barriers/photoelectric curtains, mechanical interlocks, pull-back restraints
13. 7 Marks
    aAnalyze the impact of forces, pressure and power requirements on the press working process.
    How to answer

    • Calculation of cutting force: $F = L \cdot t \cdot \tau_s$
    • Methods to reduce peak force: applying shear to punch or die faces
    • Energy required per stroke: $E = F \cdot s$, flywheel energy storage role
    • Motor power selection based on cycle time, stroke length, and tonnage rating
14. 7 Marks
    bDiscuss the significance of stock feeders and scrap cutters in maintaining efficiency during press working.
    How to answer

    • Role of stock feeders: automated, precise feeding of sheet coil, types (roll feed, gripper feed, air feed)
    • Impact on production rate, dimensional repeatability, and material handling reduction
    • Role of scrap cutters: chopping continuous scrap skeleton into small pieces, preventing jamming and enabling easy recycling
    • Contribution of both to automated high-speed stamping operations
15. 7 Marks
    aDescribe the introduction to milling, grinding and drilling machines and their role in metal machining.
    How to answer

    • Milling machine: multi-point rotating cutter, producing flat, contoured surfaces, slots, and gears
    • Drilling machine: multipoint tool producing cylindrical holes in solid workpieces
    • Grinding machine: abrasive wheel for precision finishing and tight dimensional tolerances
    • Roles and sequencing in manufacturing process workflows
16. 7 Marks
    bDiscuss the working principle and operations of shaper and planner machines.
    How to answer

    • Working principle of shaper: reciprocating ram carries tool over stationary workpiece, quick return mechanism
    • Working principle of planer: reciprocating heavy table carries workpiece past stationary tool head(s)
    • Common operations: machining horizontal, vertical, and angular flat surfaces, cutting keyways and slots
    • Key operational differences between shaper (small workpieces) and planer (large/heavy castings)