Dr. Gregory Morscher


Dr. Gregory Morscher

Title: Associate Professor
Department: Mechanical Engineering
Office: ASEC 574
Phone: 330-972-7741
Fax: 330-972-6027
Email: gm33@uakron.edu


Biography

Morscher has worked in the area of high temperature materials and composites for over twenty years. Before joining the University of Akron, he was previously affiliated with NASA Glenn (formerly Lewis) research center as a research engineer (CWRU) and then senior research scientist (OAI). He has concentrated primarily on the understanding and improvement of SiC-based composites as well as NDE techniques for the purpose damage assessment and monitoring. He studied the high temperature creep properties of ceramic fibers and developed a simple bend stress relaxation test to evaluate relative creep properties of ceramic fibers. He has also made considerable contributions to the improvement of BN interphases for the purpose of improving the intermediate temperature capability of SiC/SiC composites in oxidizing environments. Dr. Morscher has used non-destructive techniques such as acoustic emission and electrical resistance during room and high temperature testing as a monitor and measure of the amount of matrix cracking and other forms of damage that occurs as a function of stress, time, and environment (oxidation). This has served as the basis for modeling stress-strain behavior of SiC/SiC composites for different woven architectures and led to the development of intermediate and high temperature stress-rupture models for SiC/BN/SiC composites in air as a function of stress, time, and accumulated damage. More recently, he has focused on the effect of fiber-architecture and matrix-type on time-dependent mechanical behavior at high temperatures (> 1200oC) as well as joining ceramic composites to metals. In addition, he has applied acoustic emission to other material systems (e.g., polymer matrix composites and metal oxide scale spallation), other structures (e.g., foam/core structures and integrated structures), and Stirling engines. He received his B.S. degree in Ceramic Engineering at The Ohio State University in 1986 and his M.S. degree in Materials Science and Engineering at Case Western Reserve Universtiy in 1989. Later, he received his Ph.D. degree in Materials Science and Engineering at Case Western Reserve University in 2000, while working as a Research Associate at NASA Glenn. Dr. Morscher has authored or coauthored over 90 publications in refereed journals or proceedings and has been a frequent contributor to NASA Glenn’s annual Research and Technology Reports. He has received several OAI achievement awards, two NASA Tech Brief awards, two NASA Turning Goals into Reality awards, the 2004 NASA Public Service Medal and the Richard M. Fulrath Award from the American Ceramic Society in 2005.


Research Accomplishments

·       Microstructure/property relationships of ceramic matrix composites

·       Process development of ceramic matrix composites including all aspects of constituent materials and fiber architecture

·       Acoustic emission for damage determination and general monitoring of composites, structures, and machines

·       Other structural health monitoring techniques, e.g., electrical resistivity

·       Integration technologies for dissimilar materials

Publications

G. Morscher, P. Pirouz, and A.H. Heuer, "Temperature Dependence of Interfacial Shear Strength in SiC-Fiber-Reinforced Reaction-Bonded Silicon Nitride,"  J. Am. Ceram. Soc., 73 [3] 713-20 (1990).

G.N. Morscher, P. Pirouz, and A.H. Heuer, "Temperature Dependence of Hardness in Yttria-Stabilized Zirconia Single Crystals,"  J. Am. Ceram. Soc., 74 [3] 491-500 (1991).

G.N. Morscher and J.A. DiCarlo, "A Simple Test for Thermomechanical Evaluation of Ceramic Fibers," J. Am. Ceram. Soc., 75 [1] 136-40 (1992).

G.N. Morscher, “Tensile Stress Rupture of SiCf/SiCm Minicomposites with Carbon and Boron Nitride Interphases at Elevated Temperatures in Air,”   J. Am. Ceram. Soc., 80 [8] 2029-42 (1997)

G.N. Morscher, “Modal Acoustic Emission of Damage Accumulation in a Woven SiC/SiC Composite,” Comp. Sci. Tech. 59 687-697 (1999).

G.N. Morscher and J. Martinez-Fernandez, “Fiber Effects on Minicomposite Mechanical Properties for Several Silicon Carbide Fiber – Chemically Vapor-Infiltrated Silicon Carbide Matrix Systems,” J. Am. Ceram. Soc. 82 [1] 145-55 (1999)

N.S. Jacobson, G.N. Morscher, D.R. Bryant, and R.E. Tressler, “High-Temperature Oxidation of Boron Nitride: II, Boron Nitride Layers in Composites,” J. Am. Ceram. Soc., 82 [6] 1473-82 (1999)

G.N. Morscher, J. Hurst, and D. Brewer, “Intermediate-Temperature Stress Rupture of a Woven Hi-Nicalon, BN-Interphase, SiC-Matrix Composite in Air,” J. Am. Ceram. Soc., 83 [6] 1441-49 (2000)

G.N. Morscher and J.D. Cawley, “Intermediate Temperature Strength Degradation in SiC/SiC Composites,” J. European Ceramic Society, vol. 22, no. 14-15, pp. 2777-2788 (2002)

G.N. Morscher, “Stress-Dependent Matrix Cracking in 2D Woven SiC-fiber Reinforced Melt-Infiltrated SiC Matrix Composites”, Comp. Sci. Tech., 64 pp. 1311-1319 (2004)

J.A. DiCarlo, H-M. Yun, G.N. Morscher, and R.T. Bhatt, "SiC/SiC Composites for 1200oC and Above" Handbook of Ceramics Composites, Chapter 4; pp. 77-98 (Kluwer Academic; NY, NY: 2005)

G.N. Morscher, H.M. Yun, J.A. DiCarlo, "Matrix Cracking in 3D Orthogonal Melt-Infiltrated SiC/SiC Composites with Various Z-Fiber Types", J. Am. Ceram. Soc., 88 [1] 146-153 (2005)

G.N. Morscher and V. Pujar, “Creep and Stress-Strain Behavior After Creep for SiC Fiber Reinforced, Melt-Infiltrated SiC Matrix Composites” J. Am. Ceram. Soc. 89 [5] 1652-1658 (2006)

G.N. Morscher, M. Singh, and T. Shpargel, “Comparison of Different Braze and Solder Materials for Joining Titanium to Composites,” Welding Journal, Vol. 86, No. 3, pp. 62-66 (2007)

Morscher, G.N.; Yun, H.M.; DiCarlo, J.A., In-Plane Cracking Behavior and Ultimate Strength for 2D Woven and Braided Melt-Infiltrated SiC/SiC Composites Tensile Loaded in Off-Axis Fiber Directions, J. Am. Ceram. Soc. 90 [10] 3185-3193 (2007)

C.E. Smith, G.N. Morscher, and Z.H. Xia, “Monitoring Damage Accumulation in Ceramic Matrix Composites Using Electrical Resistivity,” Scripta Mat, 59 463-466 (2008)

M. Singh, G.N. Morscher, T.P. Shpargel, and R. Asthana, “Active Metal Brazing of Titanium to High Conductivity Carbon-Based Sandwich Structures”, Mater. Sci. Eng. A, 498 [1-2] 31-36 (2008)

G.N. Morscher, G. Ojard, R. Miller, Y. Gowayed, U. Santhosh, J. Ahmed, and R. John, “Tensile Creep and Fatigue of Sylramic-iBN Melt-Infiltrated SiC Matrix Composites: Retained Properties, Damage Development, and Failure Mechanisms” Comp. Sci. Tech., 68 3305-3313 (2008)

G.N. Morscher and V.V. Pujar, “Design Guidelines for In-Plane Mechanical Properties of SiC Fiber-Reinforced Melt-Infiltrated SiC Composites,” Int. J. Appl. Ceram. Technol. 6 [2] 151-163 (2009)

A. Gyekenyesi, R. Martin, G. Morscher, and R. Owen, “Impedance Based Structural Health Monitoring of  a Ceramic Matrix Composite,” Journal of Intelligent Material Systems and Structures 20 [7] 875-882 (2009)

G.N. Morscher, J.A. DiCarlo, J.D. Kiser, and H.M. Yun, “Effects of Fiber Architecture on Matrix Cracking for Melt-Infiltrated SiC/SiC Composites”. Int. J. Appl. Ceram. Technol, 7 [3] 276-290 (2010)

G.N. Morscher, “Tensile Creep and Rupture of 2D-woven SiC/SiC Composites for High Temperature Applications,” J. Euro Ceram Soc., 30 [11] 2209-2221 (2010)

G.N. Morscher, R. John, L. Zawada, D. Brewer, G. Ojard, A. Calomino, “Creep in vacuum of woven Sylramic-iBN melt-infiltrated composites” Comp. Sci. Tech., 71 [1] 52-59 (2011)

G.N. Morscher, “Tensile creep of melt-infiltrated SiC/SiC composites with unbalanced Sylramic-iBN fiber architectures,” Int. J. Appl. Ceram. Technol., 8 [2] 239-250(2011)

C.E. Smith, G.N. Morscher, and Z. Xia, “Electrical resistance as a nondestructive evaluation technique for CVI SiC/SiC ceramic matrix composites under stress-rupture conditions,” Int. J.Appl. Ceramic Technology, 8 [2] 298-307 (2011)