M.tech project progress seminar i__sohini

Progress Seminaron

Laser Based Additive Manufacturing: State of Art, Heat Transfer Analysis and Capabilities

By Sohini Chowdhury (MT/14/CIMA/01)

Under the Supervision of

Dr. M.Chandrashekharan & Mr. N. Yadaiah

Department of Mechanical Engineering North Eastern Regional Institute of Science & Technology

October 2015

Outline Introduction

Literature Review

Research objectives

Theoretical background

Conclusion

Future work and Work Plan

References

1

Introduction 2

Additive manufacturing (AM) is a process for joining materials to make objects from 3D model data, usually layer upon layer, as opposed to ‘subtractive manufacturing’ methodologies” [Ref ].

General principle

3D CAD model data Sliced layers 3D object

Ref : American Society for Testing and Materials.

This results into molten pool formation and solidification of the alloy powder as the beam traverses across the length.

The alloy powder flows coaxially with the laser beam and the particles absorbs the energy from the beam.

Schematic of laser based AM process

3Introduction Contd…

Repeated traverse of the laser beam leads to generation of multi layered component.

As the particles are deposited, laser provides sufficient thermal energy to melt the particles along the deposition path.

Introduction Contd… 4

Advantages Ability to create almost any shape or geometric features

No tooling is required

Flexibility in design

Reduction in waste

Disadvantages It requires more controllable process parameters.

High feedstock cost.

Not economical for mass production.

Applications Aerospace ( Fan blades, vanes etc)

Automotive (Car wheel, gear box, car brake etc)

Consumer (Jewellery, furniture, lightning etc)

year &Authors Work done by authors Remarks

(2006)C.P. Paul et al.

Examined the influence of processing parameters in fabricating multi-layered Colomony-6 components by laser assistance.

Results were compared with that

fabricated by GTAW

(2011)A. Kumar et al.

Developed a FE based heat transfer model to simulate the single track geometry of SS316L during LRM. In this work, authors have examined the effect of laser power, laser beam size, scan speed, powder feed rate and powder stream diameter.

Correlated experimental and simulated results.

(2011)E. Louvis et al.

Aluminium and its alloys are difficult to process than stainless steels and commercially pure titanium. For avoiding oxide film formation in Al components, SLM process is implicated to break up these oxides if highly dense (100%) aluminum components are to be formed.

Controlling oxidation process

and disrupting oxide films produced

within the component with the

laser beam

5Literature Review

year &Authors Work done by authors Remarks

(2012)B. Vayre et al.

For each shape and chosen manufacturing process, an optimization is conducted to minimize the volume by varying the value of parameters with specified mechanical behavior (using FEA) and finally the validation of the part, accomplished by a prototype.

It highlighted the designing processes

for AM process.

(2012)L. E. Murr et

al.

Comparative examples for SLM and EBM fabricated components which includes Cu, Ti–6Al–4V, alloy 625 (a Ni-base superalloy), a Co-base superalloy, and 17-4 PH stainless steel for detecting micro structure properties by altering the process parameters.

Experimental comparison of 2 AM

processes.

(2013)B. Cheng et al.

The process parameter effects (beam speed) on the temperature profile along the melt scan and the corresponding melt pool geometric characteristics such as the length-depth ratio and the cross-sectional area on Ti-6Al-4V were investigated for quality control.

Numerical simulation to establish

relationship between process parameters

and melt pool geometry.

6Literature Review Contd…

year &Authors

Work done by authors Remarks

(2014)V. Manvatkar

et al.

A three-dimensional heat transfer and material flow model is developed for numerical simulation of temperature and velocity fields of SS316 material and the effects of process parameters on the thermal cycles, build geometry, cooling rates and solidification parameters in a multilayer laser based AM process are studied.

Comparison of numerical results with

experimental data obtained from an

independent literature.

(2014)P. Michaleris

Finite element techniques are utilized for modeling of metal deposition for heat transfer analysis of metallic parts using both laser and electron beam assisted AM ways and techniques for minimizing errors are also implemented.

Quiet and deactive element technique used for FE technique.

(2014) Y. Li et al.

Simulation was performed using FE method. Sound metallurgical bonding of CP Ti powder between the fully dense layers was achieved at laser power of 250W and scan speed of 200 mm/s.

Numerical simulation using ANSYS

multiphysics and experimental studies .

7Literature Review Contd…

year &Authors

Work done by authors Remarks

(2014) L.E. Murr

Microstructures and residual mechanical properties are discussed for selected metal and alloy components which includes Ti-6Al-4V, Co-Cr-Mo super alloy, Ni-base super alloy systems (Inconel 625, 718 and Rene 142), Nb and Fe in contrast to more conventional wrought and cast products

Residual properties of EBM-fabricated

components are better than conventional cast or

wrought products.

(2014)H. Gong et al.

Laser or electron beam power fluctuations, surface gas flow, and raw material characteristics influences defect generation, in addition to the effect of process parameters variations of Ti–6Al–4V samples .

Defect generation is experimentally studied.

(2015)N. Shamsaeia et.al.

To determine the mechanical properties of Ti-6Al-4V parts so as to predict their performance while in service. Also methods to optimize and control the DLD process parameters.

Overview of microstructure and post

–manufacture mechanical properties.

8Literature Review Contd…

year &Authors

Work done by authors Remarks

(2015)E. Rodriguez et al.

Approximation of absolute surface temperature measurements of Ti-6Al-4V by electron beam additive manufacturing technology using in situ infrared thermography.

Synchronization of thermal camera (IR) to

capture images at different events.

(2015)Y. Zhang et al.

To construct build time estimation models more rapidly and simply to meet the needs of price quotation, design, process planning and optimization in AM, with acceptable accuracy by inputting less data.

Modeling method derived from Grey

theory.

(2015)A. R. Nassar et al.

The microstructure and indentation hardness of a Ti-6Al-4V component processed with a pulsed laser beam and a continuous wave (CW) laser beam were investigated. The pulsed-beam build showed not much significant variation in mechanical properties with that of CW beam.

Experimental work performed for validating mechanical properties.

9Literature Review Contd…

Objectives and proposed project title 10

Based on the detailed literature review and interest on an emerging technology, laser based additive manufacturing process, the

motivation of present work has been directed to

‘Laser based additive manufacturing process: State of the art, heat transfer analysis and capabilities’.

To achieve the present research objective, following modules are/will be accomplished either simultaneously or sequentially:

A comprehensive understanding of mechanism and physical processes involved in additive manufacturing process. Development of a conduction heat transfer process model based on finite element method using temperature dependent material properties, latent heat of fusion and Gaussian distributed volumetric heat source to compute temperature distribution, cooling rate, melt pool geometry etc.

during single layer AM process during multi layer AM process

Computed results are compared with experimental values which are adapted from an independent literature.

Transient Heat conduction (Governing) Equation:

Theoretical Background

Natural boundary condition (convection and radiation heat losses)

( , , , 0) oT x y z t T

Initial condition:

.)()( QTkTvC p

12

ρ - Density of the material. Cp - Specific heat.

ν - Velocity vector .T - Temperature variable . - Gradient operator. k - Thermal conductivity .Q - Rate of internal heat generation per unit volume.q – heat flux.h- Coefficient for heat convection. - Stephan-Boltzmann constant. σ - Melt pool emissivity.

4 40 0( ) ( ) 0Tk q h T T T T

n

Theoretical Background 12

Heat Source Models:

Gaussian distribution of circular disc heat source model [Pavelic et al. (1969)] 2 2 2

3/2 2 2 2

6 3 3 3 3( , , ) exp( )ff

f f

f Q x y zq x y zabc a b c

2 2 2

3/2 2 2 2

6 3 3 3 3( , , ) exp( )rr

r r

f Q x y zq x y zabc a b c

Double ellipsoidal heat source model [Goldak et al. (1984)]

2 2

2 2

3 3( )exp( )P x yqtr r

Theoretical Background contd… Laser beam when irradiates on the top

surface of the powder bed, a fraction of

laser energy reflects and the remainder is

absorbed.

The absorbed laser energy melts the

powder, thereby yielding a small-size

molten pool.

The majority of the incidence energy is

transferred via conduction through the

deposited layers.

Heat is quickly conducted away by the

substrate at the bottom where as convection

and radiation is more profound at the lateral

surfaces.

Boundary conditions involved in AM process

Adapted : Y. Li, D. Gu, Mater. Design, 2014.

13

14 Conclusion A detailed study was undertaken to understand the mechanism and other significant

parameters of Additive Manufacturing process in general and lased based additive manufacturing process in particular..

An extensive literature review was conducted on the influence of different parameters, experimental and numerical modeling of laser based AM.

Also, the mathematical background involved in modeling of laser based AM such as governing equation, boundary and initial conditions; and the type of heat source models have studied.

Heat transfer analysis of single layer laser based AM was performed to estimate the thermal cycles and melt pool. However, it is not shown at this moment due to verification of the model with experimental results is not done.

Future Work:

Heat transfer analysis of multi-layer laser based additive manufacturing using FEM (FE software ANSYS) to estimate the temperature distribution, cooling rates and melt pool formation in different layers.

& the detailed work plan as follows:

Plan of work

S.No. Proposed work Oct.-Dec. 2015

Jan.-March 2016

April May 2016

1 Literature review

2 Numerical modeling

3 Experimental work if any

4 Thesis writing

15

16 References

1. S. M. Thompson, L. Bian, S. Nima, and Y. Aref, Addit Manuf, 8, 36 (2015).

2. V. Manvatkar, A. De, and T. Debroy, Mater. Sci. Technol. 31, 8 (2015).

3. P. Michaleris, finite Elem. Anal. Des. 86 , 51(2014).

4. Y. Li, and D. Gu, Mater. Design. 63, 856 (2014).

5. F. Kong, and R. Kovacevic. Metall. Mater. Trans B. 41, 1310 (2012).

6. A. V. Gusarov, I. Yadroitsev, P. Bertand, and I. Smurov. Appl Surf Sci. 254, 9 (2007).

7. A. V. Gusarov, and I. Smurov, Appl Surf Sci, 255, 9 (2009).

8. A. V. Gusarov, and I. Smurov. Phys Procedia, 5, 94 (2010).

9. Y. W. Zhang, A. Faghri, C.W. Buckley, and T. L. Bergman. J Heat Transfer, 122, 8 (2000).

17

10. T. B. Chen, and Y. W. Zhang. Appl. Phys A. 86, 20 (2007).

11. I.A. Roberts, R. Wang, C.J. Esterlin, M. Stanford , and D. J. Mynors, Int. J. Mach. Tools. Manuf. 219, 84 (2005).

12. W. Hofmeister, M. Wert, J. Smugeresky, J. Philliber, M. Griffith, and M. Ensz, JOM. 51 (7), (1999).

References contd…..

Thank Youfor your kind attention