Research

  1. ICME Enhanced Development of TiAl for Advanced Aerospace Components 

  2. Fatigue and Fracture of implantable cables 

  3. Effects of Sensitization on Fracture Resistance of 5xxx Aluminium Alloys

  4. Size Scale and Confinement Effects on Plasticity and Fracture in Metallic Glasses

  5. Alloy Design for High Density Metallic Glasses/Composites with High Toughness

  6. Nitinol Commercialization Accelerator

  7. Hydrostatic Extrusion of Nano-ODS Steels

  8. Fracture and Fatigue of Naval 5xxx Alloys

  9. Rapid Qualification Methods for Powder Bed Direct Metal AM Processes

Recent :

  1. Fracture and Fatigue of Lightweight Alloys for Energy Storage

  2. Ultrasonic Bonding of Amorphous Metal Foils

  3. US-Egypt Collaborative Grant - Processing and Mechanical Properties of Amorphous Metal Foil and Laminates

  4. Damage Tolerant Structural Amorphous Metals: Intrinsic and Extrinsic Approaches for Ultralight Systems

  5. Low Mass Aerospace Ball Bearing Retainer Development

  6. Ultra-high Temperature Refractory Alloys for Aerospace Applications

  7. High Performance Corrosion Resistant Coatings

  8. Effects of Changes in Strain Rate and Test Temperature on Mechanical Behavior of HSLA-65 Steel Relevant to Friction Stir Welding Condition

  9. Ultra-high Temperature Metallic Glasses

  10. Fundamantal Approaches to Design of Tough Fe-based Metallic Glasses

  11. Effects of Interfaces on Blast Resistance of Amorphous Metals

  12. Fracture and Fatigue of Amorphous Aluminum Alloys

 

1. Fatigue and Fracture of implantable cables 


A team of materials scientists is supporting the development of Networked Implantable Neuroprostheses (NNPS) Systems on an NIH-Bioengineering Research Partnership with theCleveland Functional Electrical Stimulation (FES) center. The Materials Group is leading the material and structural evaluation, analysis, and testing of implantable leadwires and interconnects that form part of the NNPS. Currently the potential use of silver cored Drawn Filled Tube (DFT) cables as leadwires is being investigated. The response of various configurations of the DFT cables to static and cyclic mechanical loading imposed during long-term implantation is being studied experimentally. Evaluation of mechanical integrity of interconnects that joins the leadwires with the various modules of the NNPS system is also currently underway.

Upper Extremity NNPS

 

Electrodes for NNPS

(Images coutesy: Cleveland FES center )

Tension and fatigue behavior of DFT cables with various configurations as shown below are under investigation

(Images coutesy: Fort Wayne Metals )

 

7x7 implantable cable tested in Flex tester 
(Image coutesy: http://www.fortwaynemetals.com)

 

For more information:

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Journal Papers:seifi

 

3. Effects of Alloying Addition and thermal Exposures on Fracture Resistance of 5xxx Aluminium Alloys


Support: ONR


The effects of microstructural changes and thermal exposures on the energy absorbing ability of 5XXX aluminum alloys is being determined under quasi-static and fatigue conditions. Microstructural changes are being documented using TEM on both annealed and service-exposed materials while fracture toughness and fatigue studies are also being conducted in conjunction with Prof. Vikas Prakash, Mechanical and Aerospace Engineering Department, on both as-received and service-exposed materials.

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Master Plan B Tehsis:

 

4.Size Scale and Confinement Effects on Plasticity and Fracture in Metallic Glasses

Support: ARO

The effects of changes in size scale and confinement on the plasticity and fracture behavior of metallic glasses is being determined.  Confinement effects are being determined by testing metallic glasses in tension with different levels of superimposed hydrostatic stress. Recent work has extended this to conducting similar tests at high temperature in the presence of high hydrostatic pressure.  Size scale effects are being determined on both micro- and nano-wires of metallic glass prepared in both our laboratory and collaborators. The effects of changes in size scale on the plasticity and fracture behavior are being determined.

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5.Alloy Design for High Density Metallic Glasses/Composites with High Toughness

Support: DTRA

A team of investigators from University of Virginia, Carnegie-Mellon University, and CWRU are exploring predictive modeling techniques (CMU/UVa) to produce metallic glasses with both high density and high toughness.  Alloys are being designed to produce materials with high poisson’s ratio, as this has been shown to produce metallic glasses with both high toughness (CWRU) and high plasticity (UVa). Alloys based on Ni-Ta, Co-Ta, and W-based glasses are being explored.

6.Nitinol Commercialization Accelerator

Support: Ohio Third Frontier

 The Ohio Third Frontier Wright Projects Program has funded a collaborative effort between the Cleveland Clinic, CWRU, University of Toledo, NASA Glenn Research Center, and Norman Noble, Inc. in order to develop a better understanding of the metallurgical processing and mechanical characterization of nitinol for use in biomedical and aerospace applications. Biomedical applications range from orthodontia to implantable devices while higher temperature shape memory alloys are of interest for aerospace. The collaboration is designed to create synergy amongst collaborators in the research and development of nitinol products. CWRU is developing a facility wherein the effects of composition changes on mechanical performance can be determined. The laboratory housed at CWRU’s Materials Science and Engineering Department contains processing and characterization (thermal and mechanical) equipment that allows for the manufacture and analysis of nitinol products.

7.Rapid Qualification Methods for Powder Bed Direct Metal AM Processes

Support: National Additive Manufacturing Innovation Institute (NAMMI)

This collaborative project links 5 Universities, 5 Industrial members, and 2 Government Laboratories to target the missing links for understanding and controlling melt pool geometry, material microstructure and mechanical properties across both the Direct Metal Laser Sintering (DMLS) and Electron Beam Melting (EBM) additive manufacturing (AM) processes.  Both DMLS (by EOS) and EBM (by Arcam) use a rapidly moving laser or electron beam to locally melt powder particles on top of a growing metallic part.  Metal parts can be fabricated directly, with little or no user intervention.  Establishing links between process variables, material microstructure and mechanical properties is essential to qualifying these processes for use in the aerospace and other industries. The primary achievement for this TRL 4-7 project will be to provide these links to current users of these processes in the U.S. aerospace industry (represented by Pratt & Whitney, GE Aviation and Lockheed Martin) and a broad group of companies considering whether and where to integrate direct metal AM into their production streams (represented by Kennametal and Bayer).This technical approach to understanding DMLS and EBM will be combined with first-edition AM cost analysis tools.

Our project goals are made possible by taking a unique modeling-based process mapping approach that will be integrated with resulting microstructure and properties in order to characterize and better understand these AM processes. That approach will be linked to not only on-site industrial part fabrication but also U.S.-leading research on AM process/property relationships at Carnegie Mellon University, Case Western Reserve University, Wright State University, North Carolina State University, the University of Louisville, Oak Ridge National Laboratory, and NIST. Six project tasks are identified to achieve these goals, while contributing to education and workforce development at partner institutions.

Recent Publication: 

Recent:

 

1. Fracture and Fatigue of Lightweight Alloys for Energy Storage


Support: Luxfer, USA


6xxx aluminum alloy cylinders for energy storage applications are being evaluated mechanically.  Fracture and fatigue experiments are being conducted on samples excised from the cylinders over a range of strain rates and loading conditions on different compositions in order to determine the effects of composition and processing on the resulting properties.

 

2. Ultrasonic Bonding of Amorphous Metal Foils


Support: Boeing/DARPA


Ultra-lightweight amorphous metals are being bonded via a variety of ultrasonic techniques. The mechanical behavior of the amorphous metal foils are being determined both before and after bonding by using a variety of testing techniques including: Hot microhardness testing, tension testing, interface toughness measurements, interface strength measurements.

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3. Damage Tolerant Structural Amorphous Metals: Intrinsic and Extrinsic Approaches for Ultra-Light Weight Systems


Support: DARPA


The effects of INTRINSIC and EXTRINSIC approaches to improving the balance of mechanical properties in ultra-light weight bulk metallic glasses is being investigated. INTRINSIC approaches include changing the elastic constants via chemistry changes in order to produce more ductile/tough systems. EXTRINSIC approaches include compositing in order to produce more energy absorbing systems.

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4. US-Egypt Collaborative Grant - Processing and Mechanical Properties of Amorphous Metal Foil and Laminates


Support: NSF International Collaborative Program


The effects of chemistry changes on the mechanical behavior of Fe-based metallic glasses are being determined in tension, bending, flex bending fatigue, and notched/precracked toughness. In addition, lamination studies are being conducted in order to improve the mechanical behavior of the Fe-based metallic glass materials.

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5. Low Mass Aerospace Ball Bearing Retainer Development


Support: TIMKEN/AFRL


The fracture and fatigue behavior of candidate bearing retainer materials are being evaluated over temperature ranges relevant to potential applications.

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6. Ultra-high Temperature Refractory Alloys for Aerospace Applications


Support: GE


The fracture and fatigue behavior of advanced Nb alloys are being determined over a range of test temperatures. Both SEM and Laser Confocal Microscopy are being used to characterize the microstructures and crack paths selected under monotonic and cyclic loading conditions.

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7. High Performance Corrosion Resistant Coatings


Support: DoE


HVOF coatings have been prepared using Fe-based bulk metallic glasses. The performance of the coatings as well as drop cast ingots of the Fe-based bulk metallic glass have been determined over a range of temperatures using hot hardness and compression testing in addition to fracture toughness measurements. The effects of thermal exposures on microstructure evolution and resulting properties have also been determined.

8. Effects of Changes in Strain Rate and Test Temperature on Mechanical Behavior of HSLA-65 Steel Relevant to Friction Stir Welding Conditions


Support: ONR


The effects of changes in test temperature and strain rate on the flow stress of HSLA-65 relevant to friction stir welding conditions is being determined. Collaborative work with Prof. Vikas Prakash, Mechanical and Aerospace Engineering Department, is being conducted to devise experiments to probe the mechanical behavior of steels under conditions relevant to friction stir welding conditions.

Conference Posters:

High Strain/Temperature Experiments Relevant to Friction Stir Welding of HSLA-65

9. Ultra-High Temperature Metallic Glasses


Support: AFOSR


The effects of changes in composition on the glass transition temperature and mechanical behavior are being determined for a range of metallic glasses and test temperatures.

10. Fundamantal Approaches to Design of Tough Metallic Glasses


Support: University of Virginia/ONR


Description: The effects of systematic changes in the chemistry of Fe-based bulk metallic glasses on the toughness is being investigated. Systematic changes to the chemistry are being performed in order to change the elastic constants in a manner more conducive to plastic flow and enhanced toughness.

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11. Effects of Interfaces on Blast Resistance of Amorphous Metals


Support: ONR


Description: The effects of interfaces on the energy absorbing characteristics of bulk metallic glasses are being determined. Both Zr-based and Fe-based bulk metallic glasses are being tested under quasi-static and high strain rate conditions via collaborations with Prof. Vikas Prakash in Mechanical and Aerospace Engineering at CWRU. Novel insert designs have been prepared for testing while ultra-high speed video (e.g. Up to 200,000,000 frames/sec) has been utilized to capture the deformation and fracture characteristics of these novel materials.

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12. Fracture and Fatigue of Amorphous Aluminum Alloys


Support: Pratt & Whitney/DARPA


Deformation processing of amorphous aluminum alloy powders has been utilized to produce novel nanostructured aluminum composites. The effects of various processing conditions on the strength, toughness, and high cycle fatigue behavior is being determined at room temperature, 300F and 500F and compared to conventional aluminum alloys.

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Journal Papers:

Effects of Notch radius and Test Temperature on the Toughness of Nano-Crystalline Aluminium Alloy Composites

Effects of load ratio, R, and test temperature on high cycle fatigue behavior of nano-structured Al–4Y–4Ni–X alloy composites

High cycle fatigue behavior of a nanostructured composite produced via extrusion of amorphous Al89Gd7Ni3Fe1 alloy powders

Effects of Changes in Chemistry and Testing Temperature on Mechanical Behavior of Al-Based Amorphous Alloy Ribbons

Effects of Changes in Chemistry on Flex Bending Fatigue Behavior of Al-Based Amorphous Alloy Ribbons