Deformation Transfer and/or Fracture Initiation in Micro-lamellar TiAl

A scanning electron microscope technique that allows defects to be imaged in bulk specimens in a manner similar to TEM called electron channeling contrast imaging (ECCI) is used as a tool to examine the nature of deformation transfer at grain boundaries. In this study, a number of g-g grain boundaries in a TiAl alloy that display successful deformation transfer have been examined. Trace analysis based on selected area channeling patterns is used to characterize the active deformation systems in the grains on both sides of the boundaries. To interpret, and possibly predict, these observed patterns of strain accommodation/transfer at grain boundaries, a nonlinear variational model of plastic deformation in a bicrystal is being developed by D.E. Mason, in the ME department. Funded by AFOSR, grant number AFRL No. F49620-01-1-0116.

Effects of Heat Treatment on Primary Creep of TiAl

The effects of heat treatment on precipitation of carbide particles and their effect on primary creep and other mechanical properties is investigated using electron microscopy, microhardness and macrohardness measurements. Supported by Howmet Research Corp.

Microstructural Evolution from Ageing, Creep and Thermomechanical Fatigue in Lead Free Solders

Characterization and modeling of microstructural evolution due to thermomechanical fatigue in solder joints is investigated using several approaches. Currently we are using specially designed joints to facilitate observation and interrogation of the microstructure using scanning electron microscopy, orientation imaging microscopy (to map crystal orientations along with microstructure features) and nanoindentation. Recent reserach projects have included investigations into residual stress, stress relaxation, localized deformation during creep, and effects of reinforcements in composite solders manufactured by ex-situ and in-situ methods. This project is supported by a focused research group (Subramanian, Bieler, Lucas) grant from NSF (NSF-DMR-0081796), Visteon, and the Michigan State University Composite Materials and Research Center Current students: Honjoo Rhee (nano-indentation), Jong-Gi Lee (thermomechanical fatigue specimens), Adwait Telang (orientation imaging, reversed shear), Hairong Jaing (new) Students recently graduated: Sunlak Choi, Ph.D. (in-situ composite solder) Fu Guo, Ph.D. (ex-situ composite solder), Susheel Jadhav, M.S. (Stress-relaxation), Jeff McDougall (localized creep deformation)

Optimal Microstructural Design Engineering of Diamond Films

Surface morphology and crystallographic texture is characterized for a set of diamond films that were deposited with different partial pressures of nitrogen and with different times of deposition. Textures varied from 110 type fiber texture for low nitrogen, and changed systematically to 100 type fiber texture with increasing nitrogen. The effect of deposition parameters on these physical conditions and the impact they have on mechanical properties is under investigation. Collaboration with V.M. Ayres, ECE Dept.

Reducing defects in manufactured titanium fasteners

Fasteners made from Ti-6Al-4V occasionally show defects arising from the thread rolling process. This project seeks to identify the source and seriousness of these defects, so that they can be eliminated or minimized. A miniature fatigue stage to evaluate the impact of these defects on high cycle fatigue behavior is under development. Projected outcome will be to define the characteristics of a defect that can compromise performance. Supported by Fairchild Fasteners, City of Industry, CA.

Reviewed Journal Publications

C.J. Boehlert, S.C. Longanbach, and T.R. Bieler, "The effect of thermomechanical processing on the creep behavior of Udimet Alloy 188", Philosophical Magazine, Vol. 88 Issue 5 (2008) 641-664.

Bieler, T.R.; Fallahi, A.; Ng, B.C.; Kumar, D. Crimp, M.A.; Zamiri, A.; Pourboghrat, F.; Mason, D."Fracture Initiation/Propagation Parameters for Duplex TiAl Grain Boundaries Based on Twinning, Slip, Crystal Orientation, and Boundary Misorientation", Intermetallics, 13(9), 979-984, (2005).

Bieler, T.R.; Goetz, R.L.; Semiatin, S.L. "Anisotropic Plasticity and Cavity Growth during Upset Forging of Ti-6Al-4V," Materials Science and Engineering A 405, 201-213, (2005).

Telang, A.U.; Bieler, T.R. "Characterization of Microstructure and Crystal Orientation of the Tin Phase in Single Shear Lap Sn-3.5Ag Solder Joint Specimens," Scripta Materialia 52(10), 1027-31, (2005).

Zeng, L.; Bieler, T.R. "Effects of working, heat treatment, and aging, on microstructural evolution and crystallographic texture of a, a', a" and b phases in Ti-6Al-4V wire," Mater Sci. and Eng. A, 392(1-2), 403-414, (2005).

Bieler, T.R.; Nicolaou, P.D.; Semiatin, S.L. "An Experimental and Theoretical Investigation of the Effect of Colony Orientation and Misorientation on Cavitation during Hot Working of Ti-6Al-4V," Mater. Metall Trans. 36A(1), 129-140, (2005).

Fallahi, A.; Kumar, D.; Zamiri, A.; Bieler, T.R.; Crimp, M.A.; Pourboghrat, F.; Mason, D.E. "The Effect of Grain Boundary Misorientation, Inclination, Crystal Orientation, and Stress State on Microcrack Initiation in Duplex TiAl Grain Boundaries", TMS Letters 1(5), 101-2, (2004).

Ng, B.C.; Simkin, B.A.; Crimp, M.A.; Bieler, T.R. "The Role of Mechanical Twinning on Microcrack Nucleation and Crack Propagation in a Near-<span class="symbol">g</span> TiAl Alloy", Intermetallics 12(12), 1317-1323, (2004).

Jiang, H.; Fallahi, A.; Bieler, T.R.; Compton, C.; Grimm, T.L. "Evolution of Recrystallization Textures from Cold Rolling Textures in High Purity Niobium", TMS Letters 1(4), 79-80, 2004.

Crimp, M.A.; Hile, J.T.; Bieler, T.R.; Glavicic, M.G. "Dislocation Density Measurements in Commercially Pure Titanium using Electron Channeling Contrast Imaging", in TMS Letters 1(1), 15-16, (2004).

Telang, A. U.; Bieler, T. R.; Lucas, J. P.; Suburamanian, K. N.; Lehman, L. P.; Xing, Y.; Cotts, E. J. "Grain-boundary Character and Grain Growth in Bulk Tin and Bulk Lead-Free Solder Alloys," Journal of Electronic Materials 33 (12), 1412-1423, (2004).

Telang, A.U.; Bieler, T.R.; Lucas, J.P.; Subramanian, K.N.; Lehman, L.P.; Xing, Y.; Cotts, E.J. "Grain-Boundary Character and Grain Growth in Bulk Tin and Bulk Lead-Free Solder Alloys," J. Electronic Materials 33, 1412, (2004).

Telang, A.U.; Bieler, T.R.; Lucas, J.P.; Subramanian, K.N.; Lehman, L.P.; Xing, Y.; Cotts, E.J. "Grain Boundary Character and Grain Growth in Bulk Tin and Bulk Lead-free Solder Alloys," J Electronic Materials 33(12), 1412-1423, (2004).

Simkin, B.A.; Crimp, M.A.; Bieler,T.R. "A Factor to Predict Microcrack Nucleation at <span class="Symbol">g-g</span> Grain Boundaries in TiAl," Scripta Mater 49(2), 149-154, (2003).

Glavicic, M.G.; Kobryn, P.A.; Bieler,T.R.; Semiatin, S.L. "An Automated Method to Determine the Orientation of the High-Temperature Beta Phase from Measured EBSD Data for the Low-Temperature Alpha Phase in Ti-6Al-4V," Materials Science and Engineering A351, 258-64, (2003).

Glavicic, M.G.; Kobryn, P.A.; Bieler, T.R.; Semiatin, S.L. "A Method to Determine the Orientation of the High-Temperature Beta Phase from Measured EBSD Data for the Low-Temperature Alpha Phase in Ti-6Al-4V," Materials Science and Engineering A346, 50-59, (2003).

Guo, F.; Choi, S.; Subramanian, K. N.; Bieler, T. R.; Lucas, J. P.; Achari, A.; Paruchuri, M. "Evaluation of Creep Behavior of Near Eutectic Sn-Ag Solders Containing Small Amount of Alloy Additions," Materials Science and Engineering A351/1-2, 190-199, (2003).

Simkin, B.A.; Crimp, M.A.; Bieler, T.R.; Mason, D.E. "Method to index true orientation of TiAl from SACP patterns," Intermetallics 11(3), 215-23, (2003).

Simkin, B.A.; Crimp, M.A.; Bieler, T.R. "A Factor to Predict Microcrack Nucleation at Grain Boundaries," Scripta Met. et Mat. 49(2), 149-154, (2003).

Simkin, B.A.; Ng, B.C.; Bieler, T.R.; Crimp, M.A.; Mason, D.E. "Orientation Determination and Defect Analysis in the Near-Cubic Intermetallic-TiAl Using SACP," Intermetallics 11(3), 215-223, (2003).

Telang, A. U.; Bieler, T. R.; Mason, D. E.; Subramanian, K. N. "Comparisons of Experimental and Computed Crystal Rotations due to Slip in Crept and Thermomechanically Fatigued Dual Shear Eutectic Sn-Ag Solder Joints," Journal of Electronic Materials 32(12), 1455-1462, (2003).

Books, Chapters, Monographs

Bieler, T.R.; Carsley, J.E.; Fraser, H.; Smugeresky, J.E. "Trends in Materials and Manufacturing Technologies for Transportation Industries and Powder Metallurgy Research and Development in the Transportation Industry," 6th Global Innovations Proceedings, TMS: Warrendale, PA, 394, (2005).

Bieler, T.R.; Trevino, R.M.; Zeng, L. "Alloys: Titanium," in Encyclopedia of Condensed Matter Physics, Bassani, F.; Liedl, G.; Wyder, P., Eds., Elsevier Ltd, Oxford, England, 65-76, (2005).

Conference Proceedings

Ng, B.C.; Bieler, T.R.; Crimp, M.A.; Mason, D.E. "Prediction of crack paths based upon detailed microstructure characterization in a near-g TiAl Alloy," TMS MS&T 2004 Symposium on Materials Damage Prognosis; Larsen, J.M; Calcaterra, J.R.; Christodoulou, L.; Dent, M.L.; Hardman, W.J.; Jones, J.W.; Russ, S.M., eds., TMS (The Minerals, Metals & Materials Society), 307-314, (2005).

Zeng, L.; Bieler, T.R. "Microstructural, Mechanical And Crystallographic Texture Evolutions In Ti-6Al-4V," 6th Global Innovations Symposium: Trends in Materials and Manufacturing Technologies for Transportation Industries, Bieler, T.R.; Carsley, J.E.; Fraser, H.; Smugeresky, J.E., Eds., TMS: Warrendale, PA, 261-66, (2005).

Telang, A.U.; Bieler, T.R. "The Role of Special Boundaries During Solidification and Microstructure Evolution in Lead Free Solder Joints," Proceedings of International Conference on Texture of Materials, (ICOTOM 14): Leuven, Belgium, July 10-15, Materials Science Forum 495-497, 1419-1424, (2005).

Telang, A.U.; Bieler, T.R. "Dislocation Activity and Slip Analysis Contributing to Grain Boundary Sliding and Damage During Thermomechanical Fatigue in Dual Shear Lead-Free Solder Joint Specimens," International Conference on Texture and Anisotropy of Polycrystals (ITAP 2): Metz, France, 2004, Solid State Phenomena 105, 219-226, (2005).

Ng, B.C.; Crimp, M.A; Bieler, T.R.; Mason, D.E. "Studies of twin activity at crack tips in near-gamma TiAl using electron channeling contrast imaging", Gamma Titanium Aluminides 2003, ed. Y.W. Kim, H. Clemens, and A.H. Rosenberger, TMS, Warrendale, PA, 503-508, 2004.

Bieler, T.R.; Seo, D.Y.; Saari, H.; Beddoes, J. "Effect of Growth Velocity on Development of Preferred Orientations in Directionally Solidified TiAl-2Mo-2Nb", Aerospace Materials and Manufacturing: Development, Testing, and Life Cycle Issues - Honouring William Wallace, 2nd International Symposium, 43rd Annual Conference of Metallurgists of CIM Hamilton, ON, August 2004, eds. Patnaik, P.C.; Hahazi, M.; Elboujdaini, M.; Luo, J., MetSoc/CIM, 275-87, 2004.

Crimp, M.A.; Ng, B.C.; Simkin, B.A.; Bieler, T.R. "Microcrack Nucleation and Crack Propagation in <span class="symbol">g</span> TiAl," Defect Properties and Related Phenomena in Intermetallic Alloys, E.P. George, M.J. Mills, H. Inui, and G. Eggeler eds, MRS Proceedings 753, 143-148, (2003).

Jiang, H.; Bieler, T.R.; Compton, C. "Mechanical Properties, Microstructure, and Texture of Electron Beam Butt Welds in High Purity Niobium," 2003 Particle Accelerator Conference, May 12-16, Portland, Oregon, (2003).

Crimp, M.A.; Simkin, B.A.; Ng, B.C.; Mason, D.E.; Bieler, T.R. "Microscale Characterization of Deformation Defects in Bulk Intermetallic Alloys using Electron Channeling Contrast Imaging," Proc. THERMAC 2003

Crimp, M.A.; Bieler, T.R.; Mason, D.E.; Simkin, B.A.; Ng,B.C. "Deformation transfer at Gamma-Gamma Boundaries in TiAl: Experimental Characterization and Modeling," Proceedings of the US-Korea Workshop on Advances in Metallic Structural Materials, (published by the AFOSR on CD-ROM), (2003).

Bieler, T.R.; Crimp, M.A.; Mason, D.E. "Mesoscopic Measurement and Modeling of Slip Transfer Across Boundaries in Anisotropic Metallic Systems," Proceedings of the 2003 AFOSR Contractors Meeting on Metals, (Published by the AFOSR in CD-ROM), (2003).

Other Works

Bieler, T.R.; Ng, B.C.; Telang, A.U.; Crimp, M.A. "Application of OIM to Study Heterogeneous Deformation in the Vicinity of Grain Boundaries," A Collection of OIM Applications, S. I. Wright ed. EDAX Inc., 73-78, (2005).

Telang, A.U.; Bieler, T.R. "Orientation Imaging Microscopy of Lead-Free Sn-Ag Solder Joints," JOM. 57(6), 44-49, (2005).

Bieler, T.R.; Crimp, M.A.; Mason, D.E. "Mesoscopic Measurement And Meodeling of Slip Stransfer Across Boundaries in Anisotropic Metallic Systems", AFRL No. F49620-01-1-0116, , Final report, Dec. 2004.

Program Self Study Report: Materials Science and Engineering Program, According to Engineering Criteria 2000 1998-99 Accreditation Cycle, submitted by Michigan State University, July 1, 2004 to the Engineering Accreditation Commission, Accreditation board for Engineering and Technology, Inc. 111 Market Place, Suite 1050, Baltimore, MD 21202-4012.

Effect of Process Variables on Damage and Fatigue Resistance of Titanium Fasteners: Summary Report (February 26, 2003) submitted to Jeff Railton at Farichild Fasteners on 3/11/2003.

Bieler, T.R.; Crimp, M.A.; Mason, D.E.; Semiatin, S.L.; Simkin, B.A.; Ng, B.C. "Use of Crystallography and Electron Microscopy Techniques to Quantify Hetrogeneous Strain and Damage Nucleation Phenomena," Advanced Measurement Methods Web Journal, Society of Engineering Mechanics, Vol. 1 (http://www.sem.org/Afosr/) (2002).