Matthew Dahar, Mohsen Seifi, Bernard Bewlay and Prof. Lewandowski latest paper, titled “Effects of test orientation on fracture and fatigue crack growth behavior of third generation as-cast Ti–48Al–2Nb–2Cr,” has been published in Intermetallics Journal.

From the abstract: “The effects of changes in test orientation and load ratio on the room temperature fracture and fatigue crack growth behavior of as-cast Ti-48Al-2Nb-2Cr titanium aluminide was investigated to determine the presence of any anisotropy in mechanical properties. As-cast samples were tested in the longitudinal and transverse directions to the casting direction at room temperature in air. Load ratios ranging from R= 0.1 to R= 0.9 were used in the fatigue tests in order to determine its effects on the threshold for fatigue cracking, the Paris law slope, and fatigue crack instability toughness, Kc, in addition to deter- mining both notched and fatigue-precracked values for toughness. Optical metallography and SEM fractography were used to document the effects of orientation on the fracture path and morphology. Significant effects of changes in load ratio were obtained on the fatigue threshold and Paris law slope, while its effects on Kc and the effects of sample orientation were found to be minimal. These are rationalized by considering microstructural effects on the properties measured and are compared to similar materials processed via different techniques.”

The published paper can be accessed here:

M.S. Dahar, S.M. Seifi, B.P. Bewlay, J.J. Lewandowski, Intermetallics 57 (2015) 73.

John Bobanga recently completed his Masters degree and is now employed at NSWC in Washington DC as a Safety Systems Engineer. He is responsible for identifying and eliminating safety hazards in the various stages of development while meeting deadlines for delivery of fleet systems.

Kevin Macke MS student of department of Materials Sciense and Engineering at CWRU officially joined JJL research group. Kevin Joined MSE department in 2011 as a part time master student and currently is working with Thermo Fisher as an engineer.

His MS project is on the Slow Strain Rate Tensile testing in saline environment as well as slow rate fracture toughness testing. Kevin collaborate jointly with Mohsen Seifi who is working under supervision of Prof. Lewandowski Arthur P. Armington Professor of Engineering II. This project is funded by Office of Naval Research (ONR).

Freshman, Ilana Roth, sophomore, Kimaya Gupte (both pictured above) joined the group in January and will be working with PhD student, Janet Gbur on the mechanical characterization of various wires used in biomedical applications. Kimaya is a BME major from Portland, Oregon and is investigating the flex fatigue behavior of dental arch wires. Ilana is an engineering major from New Jersey and is investigating the rotating bending behavior of fine Nitinol wires. Nicole Corbin also recently joined the group and is a senior Materials Science and Engineering student working with Nitinol sheet for her senior design project.