Associate Professor
Director – Center for Welding, Joining & Coatings Research (CWJCR),
Department of Metallurgical and Materials Engineering
Office: Hill Hall Rm.370
Colorado School of Mines
920 15th Street,
Golden, CO 80401
Office Phone: (303) 273-3798 Fax: (303) 273-3795
Email: zyu@mines.edu



  • Ph.D. – Materials Science and Engineering, University of Tennessee, Knoxville, TN
  • M.S. – Metallurgy and Materials Science, University of Tennessee, Knoxville, TN
  • B.S. – Mechanical Engineering, East China University of Science and Technology (ECUST), Shanghai, China


  • Joining of similar and dissimilar materials and simulation of materials behavior;
  • Determining processing-composition-microstructure-property relations in welds;
  • In-situ characterization of material transient states during welding, e.g., non-equilibrium phase transformation and stress evolution;
  • Welding consumables design



  • American Institute for Metallurgical Engineering – The Minerals, Metals and Materials Society (AIME – TMS)
  • American Welding Society (AWS)
  • ASM international


  • MTGN 580A – Advanced Welding Metallurgy
  • MTGN 557 – Solidification
  • MTGN 442 – Engineering Alloys
  • MTGN 475/475L – Welding Metallurgy



  • Multi-Principal Element Alloy Interlayer for Manufacturing of Multi-Material Structures
  • Control of Liquid Metal Embrittlement in Galvannealed Advanced High Strength Steel Weldments by Resistance Spot Welding
  • AI-Enabled Robots for Automated Nondestructive Evaluation and Solid-State Repair of Power Plant Boilers
  • Innovative Approach to Stress Corrosion Cracking Evaluation of Canister in Dry Storage of Spent Fuel
  • Thermal-Sprayed Cladding Optimization for Steel Drill Pipes
  • Development of Technologies for Titanium to Steel Joining
  • Mitigation of Stress Relaxation Cracking in 347 Stainless Steel Weldments



  • McKay-Helm Award for the paper “Austenitic Stainless-Steel Cladding Interface Microstructures Evaluated for Petrochemical Applications” printed in Feb. 2019 in Welding Journal.
  • NSF Faculty Early Career Development (CAREER) Award, 2019, “CAREER: Understanding of Diffusion and Deformation Mechanisms in Multi-Principal Element Alloy Interlayer for Manufacturing of Multi-Material Structures”
  • Honorable Mention Poster award in Graduate Student Category. N. Switzner, Yu, M. Eff, A. Fonseca, S. Liu. “Friction and Fusion Dissimilar Welding of Stainless Steel to 1018 Steel”. Fabtech, Nov.9-12, 2015, Chicago, IL
  • First-prize winner in poster contest of Professionals Category. R. Fu, D. Du, Y. Li, Yu. “Correlation between Microstructure and Properties of Friction Stir Welded Joints of High Nitrogen Austenitic Steels”. Fabtech, Nov.9-12, 2015, Chicago, IL
  • Excellent Paper Award of Symposium in 12th IUMRS International Conference on Advanced Materials, K. Littrell, Yu, Z. Feng, U. Kinga, W. Wang, W. Xunli, “Strain-Induced Precipitates Dissolution in Al Alloys”, Qingdao, China (September, 2013)
  • Winner of 2013 TMS Technical Division Young Professional Poster Contest in Structural Materials Division. Yu, R. Barabash, O. Barabash, W. Liu, Z. Feng, “In-situ Probing of Microscopic Deformation Kinetics in Advanced High-Strength Steels”, San Antonio, TX (March, 2013)
  • First prize winner of ASM Student Research Poster Competition organized by Oak Ridge Chapter of ASM International and Smoky Mountain Section of the Society of Plastic Engineers (Nov., 2009)
  • First prize winner of Annual Sigma-Xi Student Research Competition at the University of Tennessee (April, 2009)



Peer-Reviewed Journal Articles

  1. X. Wu, Z. Wang, J.R. Bunn, L. Kolbus, Z. Feng, Z. Yu, S. Liu. “Control of Weld Residual Stress in a Thin Steel Plate through Low Transformation Temperature Welding Consumables”. Welding Journal. 99 (2020) 124-134. DOI: 10.29391/2020.99.012
  2.  Y. Gao, Z. Xue, Z. Yu. “Failure Mode Maps of Lap Joints under the Tensile Shear Testing Condition”. Extreme Mechanics Letters. 37 (2020) 100728. DOI: 10.1016/j.eml.2020.100728
  3. R. Schoell, L. Xi, Y. Zhao, X. Wu, Z. Yu, P. Kenesei, J. Almer, Z. Shayer, D. Kaoumi. “In Situ Synchrotron X-ray Tomography of 304 Stainless Steels undergoing Stress Corrosion Cracking”. Corrosion Science. Accepted 4/16/2020
  4. J. Li, B. Schneiderman, S.M. Gilbert, A. Vivek, Z. Yu, G.S. Daehn. “Process characteristics and Interfacial Microstructure in Spot Impact Welding of Titanium to Stainless Steel”. Journal of Manufacturing Processes. 50 (2020) 421-429. DOI: 10.1016/j.jmapro.2019.12.036
  5. M. Gao, B. Schneiderman, S. M. Gilbert, Z. Yu. “Microstructural Evolution and Mechanical Properties of Nickel-base Superalloy Brazed Joints”. Metallurgical and Materials Transactions A (2019) 1-11. DOI: https://doi.org/10.1007/s11661-019-05386-8
  6. M. J. Andreassen, Z. Yu, J. Bunn, and J. H. Nielsen. “Experimental Study of Residual Stresses in Hybrid Laser Arc and Submerged Arc-Welded 10-mm-Thick Low-Carbon Steel Plates”. Materials Performance and Characterization 8 (2019). DOI: 10.1520/MPC20180134
  7. N. Switzner, Z. Yu, “Austenitic Stainless Steel Cladding Interface Microstructures Evaluated for Petrochemical Applications”. Welding Journal. 98 (2019) 50-61. DOI: 10.29391/2019.98.004
  8. Z. Yu, C. Fink, B. Alexandrov, J. Schneider, “Joining of Advanced and Specialty Materials Conference Celebrates 20th Anniversary”. Welding Journal 11 (2018) 14-15
  9. K. An, D.P. Armiage, Z. Yu, R. W. Dickson, Reecca A. Mills, Z. Feng, and H. D. Skorpenske, “RHEGAL: Resistive heating gas enclosure loadframe for in situ neutron scattering”. Review of Scientific Instruments 89, 092901 (2018), DOI: 10.1063/1.5033566
  10. Z. Yu, S. M. Gilbert, S. Liu. “Review of Ti to Steel Dissimilar Joining”. Research & Development in Material Science, 5 (2018) 1-3, DOI: 10.31031/RDMS.2018.05.000623
  11. N. Switzner, Z. Yu, T. Lienert, M. Eff, A. Fonseca. “Microstructure and Mechanical Property Variations Within Inertia Friction Welded Joints of Stainless Steel to Steel”, The International Journal of Advanced Manufacturing Technology, 95 (2018) 4327-4340, DOI:10.1007/s00170-017-1568-36
  12. D. Bridges, S. Zhang, S. Lang, M. Gao, Z. Yu, Z. Feng, A. Hu, “Laser Brazing of Inconel 718 using a Ni-Mn-Fe-Co-Cu High Entropy Alloy Filler Metal”. Materials Letters 215 (2018) 11-14. DOI: 10.1016/j.matlet.2017.12.003
  13. N. Switzner, H. Querioz, J. Deurst, and Z. Yu. “Si-Bronze to 304 Stainless Steel GTA Weld Fusion Zone Microstructure and Mechanical Properties”, Materials Science and Engineering: A. 709 (2018) 55-64. DOI: 10.1016/j.msea.2017.09.025
  14. R. Alhajri, S. Liu, Z. Yu, and M.J. Andreassen. “Quantification of Residual Stresses in External Attachment Welding Applications to Evaluate the Need of Post-Weld Heat Treatment”, Welding Journal 96 (2017) 451-466, https://s3.amazonaws.com/WJ-www.aws.org/supplement/WJ_2017_12_s451.pdf
  15. Y. Wang, R. Fu, X. Zhou, G. B. Thompson, Z. Yu, and Y. Li. “Enhanced Mechanical Properties of Pure Copper with a Mixture Microstructure of Nanocrystalline and Ultrafine Grains”. Materials Letters 185 (2016) 546-549, DOI: 10.1016/j.matlet.2016.09.020
  16. X. Z. Chen, Y.Y. Fang, P. Li, Z. Yu, X.D. Wu, D.S. Li, “Microstructure, residual stress and mechanical properties of a high strength steel weld using low transformation temperature welding wires”, Materials & Design, 65 (2015) 1214-1221, DOI: 10.1016/j.matdes.2014.10.013
  17. Z. Yu, Z. Feng, D. Hoelzer, L. Tan, “Friction Stir Welding of ODS and RAFM steels”, Metallurgical and Materials Transactions E, 2E (2015) 164-172, DOI: 10.1007/s40553-015-0054-9
  18. R. Barabash, O. Barabash, M. Ojima, Z. Yu, I. Inoue, S. Nambu, T. Koseki, R. Xu, and Z. Feng, “Interphase Strain Gradients in Multilayered Steel Composite from Microdiffraction”, Metallurgical and Materials Transactions A, 45 (2014) 98-108, DOI: 10.1007/s11661-013-2100-5
  19. Z. Yu, Z. Feng, W. Woo, and S. David. “Application of In Situ Neutron Diffraction to Characterize Transient Material Behavior in Welding”, JOM, 65 (2013) 65-72, DOI:10.1007/s11837-012-0495-x
  20. Z. Yu, R. Borabash, O. Barabash, W. Liu, and Z. Feng. “Microscopic Deformation in Individual Grains in an Advanced High-Strength Steel”, JOM, 65 (2013) 21-28, DOI: 10.1007/s11837-012-0494-y
  21. Z. Yu, W. Zhang, H. Choo, and Z. Feng. “Transient Heat and Material Flow Modeling of Friction Stir Processing of Magnesium Alloy using Threaded Tool”, Metallurgical and Materials Transactions A, 43A (2011) 724-737, DOI: 10.1007/s11661-011-0862-1
  22. Z. Yu, and H. Choo. “Influence of Twinning on the Grain Refinement during High-Temperature Deformation in a Magnesium Alloy”, Scripta Materialia 64 (2011) 434-437, DOI: 10.1016/j.scriptamat.2010.11.009
  23. Z. Yu, H. Choo, Z. Feng, and S. Vogel. “Influence of Thermo-Mechanical Parameters on Texture and Tensile behavior of Friction-Stir-Processed Mg alloy”, Scripta Materialia 63 (2010) 1112-1115, DOI: 10.1016/j.scriptamat.2010.08.016

Conference Proceedings

  1. S. Gordon, X. Wu, Z. Yu, and S. Liu. “Prediction of Stress Corrosion Cracking in 304 Stainless Steel Canisters in Dry Storage of Spent Fuel by Modeling: Analysis of Weld Residual Stress and Susceptible Microstructure”. Conference proceedings of the 12th International Seminar “Numerical Analysis of Weldability”. Sep. 23-26, 2018. Graz, Castle Seggau, Austria
  2. T. Yao, M. Timko, M. Santaella, J. Ihne, Z. Yu. “Weber Metals’ Experience on Residual Stress of Al and Ti forgings”. Residual Stress Summit 2017, Oct. 23-26, 2017, Dayton, OH
  3. M. J. Andreassen, Z. Yu, S. Liu, and J. H. Nielsen. “The influence of plate thickness on the welding residual stresses from submerged arc welding in offshore steel structures”, Proceedings of EUROSTEEL 2017, Sep. 13-15, 2017, Copenhagen, Denmark, pp. 499-504, https://doi.org/10.1002/cepa.86
  4. X. Wu, Z. Yu, S. Gordon, D. Olson, S. Liu, C. Bryan, E. Schindelholz, D. Enos, and Z. Shayer. “Finite Element Analysis of Weld Residual Stresses in Austenitic Stainless Steel Canisters in Dry Storage of Spent Fuel”, Conference proceedings of 70th IIW Annual Assembly & International Conference, Jun. 25-30, 2017, Shanghai, China
  5. M. J. Andreassen, Z. Yu, S. Liu, M. P. Guerrero-Mata. “Comparison of Welding Residual Stresses of Hybrid Laser-Arc Welding and Submerged Arc Welding in Offshore Steel Structures”. Proceedings of the 10th International Conference on Trends in Welding Research. Tokyo, Japan, 2016
  6. Z. Shayer, D.L. Olson, S. Liu, Z. Yu, K. Murty, N. Kumar, and D. Kaoumi et al., “Integrated Research Program Overview on the Innovative Approaches to Marine Atmospheric Stress Corrosion Cracking Inspection, Evaluation and Modeling in Used-fuel Dry Storage Canisters”, Proceedings of Materials Science & Technology 2016, Oct. 23-27, 2016, Salt Lake City, UT
  7. Z. Yu, Z. Feng, K. An, W. Zhang, E.D. Specht, J. Chen, X.L. Wang, S. David. “Measurement of Steel Phase Transformation Kinetics by Dilatometry and In-Situ Neutron Diffraction – A Comparative Study”, Conference proceedings of 9th International Trends in Welding Research Conference, Jun. 4-8, Chicago, IL, 2012
  8. Z. Yu, Z. Feng, K. An, W. Zhang, E.D. Specht, J. Chen, X.L. Wang, S. David. “In-Situ Neutron Diffraction Study of Non-Equilibrium Phase Transformation in Advanced High-Strength Steels”, Conference proceedings of 9th International Trends in Welding Research Conference, Jun. 4-8, Chicago, IL, 2012
  9. J. Chen, W. Zhang, Z. Yu, W. Cai, Z. Feng. “Determination of Thermal Contact Conductance of Metal Tabs for Battery Ultrasonic Welding Process”, Conference proceedings of 9th International Trends in Welding Research Conference, Jun. 4-8, Chicago, IL, 2012
  10. J. Chen, W. Zhang, Z. Yu, H. Wang, Z. Feng. “Automated Spot Weld Inspection using Infrared Thermography”, Conference proceedings of 9th International Trends in Welding Research Conference, Jun. 4-8, Chicago, IL, 2012
  11. Z. Yu, Z. Feng, H. Choo, and S. Vogel, “Texture Modification and Ductility Enhancement in Mg Alloy Through Friction Stir Processing”, Proceedings of the ASME 2011 International Mechanical Engineering Congress & Exposition (IMECE), Nov. 11-17, Denver, Colorado, 2011.
  12. Z. Yu, H. Choo, W. Zhang, Z. Feng, and S. Vogel. “Influence of Friction-Stir-Welding Parameters on Texture and Tensile Behavior”, Conference Proceedings of the Society for Experimental Mechanics Series, 2011, Vol. 17, 725-726


  1. Venkata K. Manchiraju, Zhili feng, Stan David, Z. Yu. Providing Plastic Zone Extrusion. 2017, US 9616497 B2, and US20130266467
  2. John C. Bartos, Z. Yu, Feng Lu. Systems and Methods for Pulsed Friction and Friction Stir Welding, 2016, WO 2016109740 A1
  3. Venkata K. Manchiraju, Zhili feng, Stan David, Z. Yu. System for and Method of Plastic Zone Extrusion, EP 2777837 A1, CN104043669A and CA 2846713 A1. 2014