QUALIFICATION

2012 – 2016	Imperial College London, PhD in Mechanical Engineering Supervisor: Prof John P. Dear and Dr Catrin M. Davies Thesis: Experimental Characterisation and Numerical Simulation of Fibre Laser Welding of AA 2024-T3 and Ti-6Al-4V
2008 – 2012	Imperial College London, MEng in Mechanical Engineering, 2:1 Supervisor: Prof John P. Dear and Dr Catrin M. Davies Dissertation: Investigation on the Properties of Aluminium Alloy 2219 Supervisor: Prof Peter R. N. Childs Dissertation: Recycling of Plastic Wastes (1^st) sponsored by Developing Technologies
2006 – 2008	Hills Road Sixth Form College, A-Level Physics (A), Chemistry (A), Biology (A), Maths (A) and Further Maths (A)

ACADEMIC VISIT

2014	Science and Technology on Power Beam Processes Laboratory, Beijing Aeronautical Manufacturing Technology Research Institute, AVIC, Prof Li Chen

EMPLOYMENT

2017 – Present	Research Associate, Imperial College London, UK Novel Manufacture of Heat Exchangers with Hiflux (Winner of £411k Innovate UK Manufacturing and Materials Competition Research Funding)
2012 – Present	Imperial Consultants (ICON), UK Determination of Global and Local Tensile Behaviours of Welded and Parent Inconel 625 Dissertation: Recycling of Plastic Wastes (1^st) sponsored by Developing Technologies
2008	Samsung Semiconductor Europe Ltd., UK Assisted project coordination, personnel administration and management, and produced instruction documentation

GRANTS AND AWARDS

2017 – Present	Hiflux (Innovate UK grant) Research Associate
2017	Young Generation Forum (YGF) 2017 Travel Award, The Korean Federation of Science and Technology Societies
2016	AVIC Centre Research Assistant Bridging Funding
2015 – 2016	ISIS (Didcot), ILL (Lyon) and HZB (Berlin) Instrument Beam Time Award
2012 – 2016	AVIC Centre PhD Studentship (bursary/fees)

TEACHING EXPERIENCE

2012 – Present	MEng Final Year and MSc Project Supervision Fatigue Behavior of Linear Friction Welded Titanium Alloys, Microstructure Analysis of Laser Beam Welding on Aluminium Alloy Components, Friction Stir Welding of AA2024, Inertial friction welding of nickel based superalloy, Process Microstructure Performance Relationship of Selective Laser Melting of Stainless Steel 316L
2012 – Present	Graduate Teaching Assistant ME1 Design (CAD), ME2 Design (CAD), ME2 Vibrations, ME1 Mechanics

RESEARCH INTERESTS

Numerical Simulation, ABAQUS, Arc Welding, Linear Friction Welding, Friction Stir Welding, Electron Beam Welding, Laser Beam Welding, Additive Manufacturing, Materials Modelling, Weld Modelling, Finite Element Analysis, Phase Transformation, Digital Image Correlation, Thermo-mechanical Testing, Surfi-Sculpt, Comeld, Neutron Diffraction, X-ray Diffraction, Hole-Drilling, Data Analysis, High Performance Computing, Mechanical and Product Design

SKILLS

Microsoft Office, Solidworks, ABAQUS, Python, Fortran, LabVIEW, Moldflow, Hypermesh, Matlab, Linux, Korean, English

PUBLICATIONS (Download)

Journal Papers (SCI indexed)

Ahn, J., He, E., Chen, L., Dear, J. P. & Davies, C. M. (2018). Correlation between laser power, welding speed, focal position and microstructure in high power Yb-fibre laser welded 2024-T3 aluminium alloy. Optics and Lasers in Engineering, Online First (IF 2.77)

Ahn, J., He, E., Chen, L., Dear, J. P. & Davies, C. M. (2018). FEM prediction of welding residual stresses in fibre laser welded AA 2024-T3 and comparison with experimental measurement. The International Journal of Advanced Manufacturing Technology, Online First (IF 2.21)

Ahn, J., He, E., Chen, L., Dear, J. P. & Davies, C. M. (2018). Determination of residual stresses in fibre laser welded AA2024-T3 T-joints by numerical simulation and neutron diffraction. Materials Science and Engineering: A, 712, 685-703 (IF 3.10)

Ahn, J., He, E., Chen, L., Davies, C. M., & Dear, J. P. (2017). The effect of Ar and He shielding gas on fibre laser weld shape and microstructure in AA 2024-T3. Journal of Manufacturing Processes, 29, 62-73 (IF 2.32)

Ahn, J., Chen, L., Davies, C. M., & Dear, J. P. (2017). Effect of filler metal feed rate and composition on microstructure and mechanical properties of fibre laser welded AA 2024-T3. Journal of Manufacturing Processes, 25, 26-36 (IF 2.32)

Ahn, J., He, E., Chen, L., R. C., Wimpory., Dear, J. P. & Davies C. M. (2017). Prediction and measurement of residual stresses and distortions in fibre laser welded Ti-6Al-4V considering phase transformation. Materials & Design, 115, 441-457. (IF 4.36)

Ahn, J., Chen, L., Davies, C. M. & Dear, J. P. (2016). Parametric optimisation and microstructural analysis on high power Yb-fibre laser welding of Ti–6Al–4V. Optics and Lasers in Engineering, 86, 156-171. (IF 2.77)

Wang, X., Ahn, J., Kaboglu, C., Yu, L. & Bamber, B. R. K. (2016). Investigation on failure modes and mechanical properties of CFRP-Ti6Al4V hybrid joints with different interface patterns using digital image correlation. Materials & Design, 101, 188-196. (IF 4.36)

Wang, X., Ahn, J., Kaboglu, C., Yu, L. & Bamber, B. R. K. (2016). Characterisation of composite-titanium alloy hybrid joints using digital image correlation. Composite Structures, 140, 702-711.

Wang, X., Ahn, J., Bai, Q., Lu, W., & Lin, J. (2015). Effect of forming parameters on electron beam Surfi-Sculpt protrusion for Ti–6Al–4V. Materials & Design, 76, 202-206. (IF 4.36)

Davies, C. M., Ahn, J., Tsunori, M., Dye, D., & Nikbin, K. M. (2015). The Influence of Pre-existing Deformation on GMA Welding Distortion in Thin Steel Plates. Journal of Materials Engineering and Performance, 24(1), 261-273. (IF 1.33)

Ahn, J., He, E., Chen, L., Dear, J. P. & Davies, C. M. (2018). Microstructure and mechanical properties of fibre laser welded Ti-6Al-4V autogenous welds, In Draft

Ahn, J., He, E., Chen, L., Dear, J. P. & Davies, C. M. (2018). Mechanical heterogeneity of fibre laser welded AA 2024-T3 sheets, In Draft

Ahn, J., He, E., Chen, L., Dear, J. P. & Davies, C. M. (2018). Assessment of fibre laser welding of AA 2024-T3 sheets in T-joint configuration, In Draft

Ahn, J., He, E., Chen, L., Dear, J. P. & Davies, C. M. (2018). Double-sided fibre laser welding of Ti-6Al-4V T-butt welds, In Draft

Conference Papers

Wang, X., Ahn, J., Bamber, B. R. K., Mao, Z. & Li. K. (2015). Investigation of failure modes and mechanical properties of hybrid joints of different interface patterns using digital image correlation. Proceedings of the 18th International Conference on Composite Structures.

Ahn, J., Chen, L., Davies, C. M., & Dear, J. P. (2014). Parametric optimisation and joint heterogeneity characterization of fibre laser welding of AA 2024-T3. Proceedings of the 67th International Institute of Welding Annual Assembly.

Ahn, J., Chen, L., Davies, C. M., & Dear, J. P. (2014). Digital Image Correlation for Determination of Local Constitutive Properties of Fibre Laser Welding Joints in AA 2024-T3. Proceedings of the 16th International Conference on Experimental Mechanics.

Ahn, J., Chen, L., Davies, C. M., & Dear, J. P. (2014). Residual Stress Measurements in Fibre Laser Beam Welded Plates of Aluminium Alloy AA 2024-T3. Proceedings of the 16th International Conference on Experimental Mechanics.

Journal Reviews

Metallurgical and Materials Transaction A, Materials Science and Engineering A, Optics and Lasers in Engineering, Optics and Laser Technology, Metallurgical & Materials Engineering, Journal of Engineering and Technological Sciences

Surface Review and Letters, The Open Mechanical Engineering Journal