ME664A

FUNDAMENTAL OF CASTING AND SOLIDIFICATION

Credits:

  

 

3-0-0-9
 

Prereq: TA202; ESO204A OR ME231A


Solidification: Introduction, Evolution of solid/liquid interface, Solidification transport phenomena and its mathematical modelling. Casting: Introduction, Solidification rates and microstructure in casting, Transport Phenomena in casting, Fluidity, Casting defects, Casting design, Case studies of selected casting processes, Advanced means to control casting structure, properties and defects. Joining: Introduction, Physics of welding. Advanced applications of solidification principles.

No. of Lectures


I. Solidification (12 Lectures):

  • Course structure, Introduction to solidification/ melting 1

  • Nature of solid/liquid interface, Plane front solidification, Constitutional undercooling 3

  • Dendritic growth, Directional solidification 2

  • Solidification transport phenomena: Solidificationof pure metals and alloys 2

  • Mathematical modelling of solidification transport phenomena (mass and heat transfer, fluid dynamics, mushy zone, species transport), Micro and macro-segregation 4

II. Casting (23 Lectures):

  • Introduction to casting, Microstructure in casting, Mathematical treatment of solidification rates, Mold-casting heat transfer Transport Phenomena in casting 3

  • Gating and risering, Solidification shrinkage, Fluidity and its measurement 3

  • Casting defects - compositional, microstructural 2

  • Mold filling, shrinkage and other flow and heat transfer related defects 2

  • Causes - role of transport phenomena in their formation, and Remedies 2

  • Casting design – by controlling the accompanied heat transfer, fluid Flow and solidification, Riser design, Gating design, Feeding distance, Mold filling design 3

  • Case studies of selected casting processes - critical assessment of technology of mold, die and investment casting, direct chill casting, ingot casting, micro casting 5

  • Control of casting structure, properties and defects through advanced means – inoculation practices, rheocasting, thixocasting, multiphysics means involving electromagnetic fields 3

III. Welding (3 Lectures):

  • Introduction to joining, Classification of welding 1

  • Welding - physics of welding, Different zones in welding, Characteristics of arc and mode of metal transfer 2

IV. Advanced applications of solidification principles (2 Lectures):

  • Manufacturing processes, Energy 2

 

40 Lectures

Term Paper:


It should be based on analysis of solidification process (in manufacturing, energy) using solidification transport phenomena.

Suggested Readings:

  1. Science and Engineering of Casting Solidification, Doru M Stefanescu, 2nd ed.

  2. Solidification Processing, M C Fleming, McGraw Hill.

  3. Metals Handbook-Metal Casting, ASM.

  4. Casting, J Campbell, Butterworth-Heinemann.

  5. Principles of metal casting, R W Heine, C R Loper and Rosenthal, Tata McGraw Hill, New Delhi.

  6. Manufacturing Engineering and Technology, S Kalpakjian.

  7. Fundamentals of Modern Manufacturing, M P Groover.

Welding: Principles and Applications, Larry F. Jeffus, 4th ed., Thomson learning, 1999.
 

ME669A

MODELLING THERMAL TRANSPORT IN MANUFACTURING PROCESSES

Credits:

  

 

3-0-0-9
 

Prerequisites: None


Review of fundamentals of thermal transport in manufacturing: Introduction to the course, Steady and transient heat conduction, Convection and Radiation, Natural convection. Finite Volume based modelling of heat transfer in manufacturing and numerical implementation, Phase change - Enthalpy based algorithm for Melting/solidification, Two-phase mushy zone flows, Liquid- vapour phase change involved in manufacturing, Illustration using code. Case studies on modelling of thermal transport in manufacturing processes: Solidification processing – Casting, Marangoni convection driven flow, Arc, Laser/Electron beam welding. Heat assisted manufacturing process – Thermal modelling using enthalpy method for solid-liquid and/ or liquid-vapour phase change interface, Melt pool formation and flow behaviour, Beam heat flux models, Laser/ Electron beam melting, Electric discharge machining. Thermal deposition process – Modelling of free surface evolution, Modelling of droplet impact and deposition on substrates.

Lcturewise breakup:


 

Topic

No. of hours

1. Review of fundamentals of thermal transport in manufacturing

  1. Introduction to the course - Importance of heat transfer in manufacturing and applications

  2. Steady and transient heat conduction, Convection and   Radiation, Natural convection

  3. Fluid flow and Mass transfer

01

02
02

2. Finite Difference and Finite Volume based modelling of heat transfer in manufacturing and numerical implementation

  1. Basic introduction to FDM and FVM techniques, Mathematical formulation of thermal transport, Governing equations and general scalar transport equation

  2. Steady and unsteady problems, Initial and Boundary conditions, Convection-diffusion problems 

  3. Mesh terminology, Accuracy, Consistency, Stability and Convergence 

  4. Phase change - Enthalpy based algorithm for Melting/solidification, Two-phase mushy zone flows,  Liquid-      vapour phase change involved in manufacturing

  5. Illustration using code

  


02

02

01
02


02

3. Case studies on modelling of thermal transport in manufacturing processes

  1. Solidification processing – Modelling of moving melting/solidification phase change interface, Alloy solidification, Segregation, Two-phase mushy zone flow, Modelling of casting, Marangoni convection driven flow, Modelling of welding  

  2. Heat assisted manufacturing process – Thermal modelling using enthalpy method for solid-liquid and/ or liquid-vapour phase change interface, Melt pool formation and flow behaviour, Beam heat flux models, Example problems of thermal modelling in Laser Melting (LM), Electron Beam Melting (EBM), Machining: Electric Discharge Machining (EDM) and Heat assisted micro manufacturing process

  1. Thermal deposition process – Modelling of free surface evolution, Modelling of droplet impact and deposition on substrates

  


08

14

04
 

Total

40

Reference Texts:

  1. R.N.Smith, C.H Doumanidis, R. Pitchumani, Chapter 17, Heat Transfer in Manufacturing and Materials Processing, John Wiley & Sons Inc., 2006.

  2. T.L. Bergman, A.S. Lavine, F.P. Incropera, D.P. DeWitt, Fundamentals of Heat and Mass Transfer, 6th Edition, Wiley India Pvt. Ltd., 2006.

  3. S.V. Patankar, Numerical Heat Transfer and Fluid Flow, McGraw-Hill, New York, 1980.

  4. J. Dowden (Ed.), The Theory of Laser Materials Processing in Heat and Mass Transfer in Modern Technology, Springer, 2008.

  5. D.M. Stefanescu Science and Engineering of Casting Solidification, 2nd ed., Springer, 2008.

  6. M.P. Groover, Fundamentals of Modern Manufacturing, John Wiley & Sons Inc., 2010.

  7. Larry F. Jeffus, Welding: Principles and Applications, 4th ed., Thomson Learning, 1999.

  8. L. Pawlowski, The Science and Engineering of Thermal Spray Coatings, 2nd ed., John Wiley & Sons Inc, 2008.
 

ME670A

ADDITIVE MANUFACTURING

Credits:

  

 

3-0-0-0-(9)
 

Prerequisites: Instructor's permission


Aimed at:


Postgraduates and advanced undergraduates

Other Departments:


Materials Science and Engineering Aerospace Engineering, Materials Science Programme, Civil Engineering, Chemical Engineering, Design Programme.

Course Description:


Additive Manufacturing ( AM) is a process of joining materials to make objects from 3D model data, usual y layer up on layer, as opposed to subtractive manufacturing methodologies, such as traditional machining. The basic principle of AM is that a model, initially generated using a three-dimensional Computer Aided Design (3D CAD) system, can be fabricated directly. AM technologies have significantly evolved over the last decade. Because of their potential to extensively transform the nature of manufacturing processes, e.g ., by enabling "Freedom of Design" several industries have been attracted by these technologies. Using AM, manufacturing of highly complex parts can be an economically viable alternative to convention al manufacturing technologies.
AM processes can be categorized by the type of material used, the deposition technique or by the way the material is fused or solidified. Over the years, many AM processes have emerged which have their own advantages and limitations. This course is an elective subject for PG/UG students who intend to study additive manufacturing. The main objective of this course is to acquaint students with the concept of AM, various AM technologies, selection of materials for AM, modeling of AM processes, and their applications in various fields. Towards modelling in AM, relevant case studies have been included to introduce the students to the mathematical models for AM to describe the transport phenomena such as heat/mass transfer and fluid flow. The course will also cover AM process plan including building strategies and post-processing.

Course Content:


Module

Topic

No. of hours

I: Introduction to Additive Manufacturing (AM)

General overview
Introduction to reverse engineering Traditional manufacturing vis AM
Computer aided design (CAD) and manufacturing (CAM) and AM Different AM processes and relevant process physics AM process chain
Application level: Direct
processes - Rapid

05
 

Prototyping, Rapid Tooling. Rapid Manufacturing; Indirect Processes - Indirect Prototyping. Indirect Tooling, Indirect Manufacturing

 

2: Materials science for AM

Discussion on different materials used Use of multiple materials, multifunctional and graded materials in AM
Role of solidification rate Evolution of non-equilibrium structure Structure property
relationship
Grain structure and microstructure

04

3: AM technologies

Powder-based AM processes involving sintering and melting (selective laser sintering, shaping, electron beam melting. involvement).
Printing processes (drop!et based 3D
Solid-based AM processes - extrusion based fused
deposition modeling
object Stereolitho graphy
Micro- and nano-additive

04

01
03

01
03

4: Mathematical models for AM

Transport phenomena models:

03

 

temperature, fluid flow
and composition, buoyancy driven
tension driven free surface flow pool)
Case studies: Numerical Modeling of
AM process, Powder bed melting based process,

 


06
 

Droplet based printing process Residual stress, part fabrication time,
cost, optimal orientation and optimal Defect in AM and role of transport
Simulations (choice of parameter, Mo de! validation for different

01
01
02

5: Process selection, planning, control for AM

Selection of AM technologies using decision methods

02

 

Additive manufacturing process plan:

01

 

strategies and post processing. Monitoring and control of defects, transformation

03

 

 

Tota1= 40

Reference Texts:

  1. Ian Gibson, David W. Rosen, Brent Stucker, Additive manufacturing technologies: rapid prototyping to direct digital manufacturing Springer, 2010.

  2. Andreas Gebhardt, Understanding additive manufacturing: rapid prototyping, rapid tooling, rapid manufacturing, Hanser Publishers, 2011.

  3. J.D. Majumdar and I. Manna,  Laser-assisted  fabrication of materials, Springer Series in Material Science, e-ISBN: 978-3-642- 28359-8.

  4. L. Lu, J. Fuh and Y.-S. Wong, Laser-induced materials and processes for rapid prototyping, Kluwer Academic Press, 20 0 I.

  5. 5. Zhiqiang  Fan and Frank Liou, Numerical modeling  of the additive manufacturing (AM) processes  of titanium alloy, lnTech, 2012.

  6. C.K.  Chua,  K.F.  Leong  and  C.S.  Lim,  Rapid  prototyping: principles  and applications,  3rd Edition, World Scientific, 20 10.
 

ME671A

EXPERIMENTAL STRESS ANALYSIS

Credits:

  

 

(3-0-0-9)
 

Course Content:


Introduction to stress and strain and need for experimental stress analysis. Localized measurement of deformation: Electrical resistance strain gages including bridge configurations and strain amplifiers used, optical displacement and strain sensors, LVDT and capacitance based sensors. Optical methods in strain analysis: Introduction to light, coherent light sources and coherence length of a light source, Interference, optical elements (lenses, prisms, beam splitters etc. used in optical setups); Principles of optical techniques such as photoelasticity in transmission and reflection including stress separation, Geometric Moiré and Moiré interferometry, Digital image correlation and Electronic Speckle Pattern Interferometry.

Lecture wise Breakup


I. Introduction (2 Lecture):

  • Introduction to stress and strain and need for experimental stress analysis.

II. Localized measurements (8 lectures):

  • Electrical resistance strain gages

  • Bridge circuits and strain amplifiers used for conditioning strain measurements

  • Optical displacement and strain sensors

  • Linear voltage differential transducer and capacitance based displacement sensors

III. Introduction to optics (8 lectures):

  • Representing light using electric field (plane and spherical wave fronts)

  • Coherence, Coherence length and Interference

  • Diffraction of light 

  • Optical elements (lenses, prisms, beam splitters, front surface mirrors etc.)

IV. Photoelasticity (8 lectures):

  • Stress optic law

  • Analysis of plane and circular polariscope

  • Fringe counting and calibration of optical constant

  • Stress analysis using transmission and reflection photoelasticity

  • Stress separation methods

V. Full field displacement measurement techniques (16 lectures):

  • Geometric Moiré (3)

  • Moiré Interferometry (5)

  • Electronic Speckle Pattern Interferometry (4)

  • Digital Image Correlation (4)

References:

  1. Experimental Solid Mechanics, A Shukla and J.W. Dally

  2. High Sensitivity Moiré, D. Post, B. Han and P. Ifju

  3. Springer Hand Book of Experimental Solid Mechanics