About this previous year paper
ADDITIVE MANUFACTURING (KME071)
B.Tech SEM VII – Complete Solved Question Paper (2022–23)
SECTION A
Attempt all questions in brief (2 × 10 = 20 Marks)
(a) Differentiate between Additive Manufacturing and CNC Machining
Additive Manufacturing (AM) builds parts layer by layer by adding material only where required, whereas CNC machining removes material from a solid block using cutting tools. AM reduces material wastage, while CNC machining produces more scrap but offers high surface finish.
(b) What is a 3D printer?
A 3D printer is a machine that creates three-dimensional objects from a digital model by depositing material layer by layer using additive manufacturing techniques.
(c) What are the 8 steps in Additive Manufacturing?
The main steps are: CAD model creation
Conversion to STL format File transfer to AM machine
Machine setup Layer-by-layer fabrication
Part removal Post-processing
Final inspection
(d) Define the need of CAD technology for Additive Manufacturing
CAD technology is required to design accurate 3D models, modify geometry easily, simulate parts, and convert designs into machine-readable formats for AM processes.
(e) Name the two DED systems
The two Directed Energy Deposition (DED) systems are: Laser-based DED
Electron Beam-based DED
(f) Define reaction rates for photopolymers
Reaction rate for photopolymers refers to the speed at which liquid resin hardens when exposed to light during processes like stereolithography.
(g) How does Additive Manufacturing help in aerospace and biomedical applications?
In aerospace, AM helps in weight reduction, complex part design, and rapid prototyping. In biomedical applications, it enables customized implants, prosthetics, and patient-specific medical devices.
(h) What are the various materials used in material jetting?
Materials include photopolymer resins, wax-like materials, and support materials used for complex geometries.
(i) What is self-customization?
Self-customization is the ability of customers to design or modify products according to their personal requirements using digital design tools and AM technologies.
(j) How Additive Manufacturing benefits the jewellery industry?
AM allows complex designs, reduced material waste, rapid prototyping, and customized jewellery creation with high accuracy.
SECTION B
Attempt any THREE (10 × 3 = 30 Marks)
(a) Explain the nomenclature of Additive Manufacturing machines
AM machine nomenclature describes the process type, energy source, material form, and deposition method. For example, terms like Powder Bed Fusion or Material Extrusion clearly indicate how material is processed and fused during printing.
(b) Hybrid technologies used in Additive Manufacturing
Hybrid AM technologies combine additive processes with subtractive processes like CNC machining. This improves surface finish, accuracy, and functionality in a single setup.
(c) Powder Bed Fusion (PBF) process with advantages and disadvantages
In PBF, a laser or electron beam selectively melts powder material layer by layer.
Advantages: High precision, complex geometries, good mechanical properties.
Disadvantages: High cost, slow process, powder handling issues.
(d) Functions of other software systems assisting AM
Other software systems help in slicing, support generation, process simulation, error detection, material optimization, and quality inspection.
(e) Intellectual property issues related to AM machines
AM raises IP concerns such as unauthorized copying of designs, digital piracy of CAD files, and lack of clear regulations for design ownership.
SECTION C
Q3
(a) Types of Additive Manufacturing technologies
Major AM technologies include: Material Extrusion (FDM)
Vat Photopolymerization (SLA) Powder Bed Fusion (SLS, SLM)
Material Jetting Binder Jetting
Directed Energy Deposition Sheet Lamination
(b) Direct and Indirect Processes in Additive Manufacturing
Direct processes create final parts directly from AM machines, while indirect processes produce molds or patterns that are later used for casting or forming.
Q4
(a) Other associated technologies developed along with AM
Associated technologies include CAD/CAM, reverse engineering, simulation software, topology optimization, and digital manufacturing systems.
(b) Difference between metal-based and polymer-based AM systems
Metal-based AM systems use high-energy sources like lasers and electron beams, while polymer-based systems use lower energy and simpler mechanisms. Metal systems are costlier but provide stronger parts.
Q5
(a) WEAVE and STAR-WEAVE scan patterns
WEAVE scan pattern follows a back-and-forth path to reduce residual stress. STAR-WEAVE distributes heat evenly using intersecting scan paths, improving part quality.
(b) Powder handling challenges in AM
Challenges include powder contamination, health hazards, uneven particle size, oxidation, and recycling difficulties.
Q6
(a) Potential of Additive Manufacturing
AM enables mass customization, rapid prototyping, lightweight structures, reduced material waste, and decentralized manufacturing.
(b) How AM meets customization requirements
AM allows digital design modification without tooling changes, making it ideal for personalized products and small batch production.
Q7
(a) How Additive Manufacturing leads to efficient product development
AM reduces development time, enables rapid design iteration, lowers tooling costs, and improves innovation speed.
(b) Secondary rapid prototyping processes
Secondary processes include CNC machining, surface finishing, heat treatment, and coating to improve part strength and finish.