MATERIALS SCIENCE AND ENGINEERING

Professor Lewandowski's Research Group

Recent and Ongoing Research

1. Fatigue and Fracture of implantable cables
   
   
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. Fracture and Fatigue of Amorphous Aluminum Alloys


6. Effects of Interfaces on Blast Resistance of Amorphous Metals
   
   
7. Low Mass Aerospace Ball Bearing Retainer Development
   
   
8. Ultra-high Temperature Refractory Alloys for Aerospace Applications
   
   
9. High Performance Corrosion Resistant Coatings
   
   
10. Fundamantal Approaches to Design of Tough Fe-based Metallic Glasses
    
    
11. Effects of Sensitization on Fracture Resistance of 5xxx Aluminium Alloys
    
    
12. Effects of Changes in Strain Rate and Test Temperature on Mechanical Behavior of HSLA-65 Steel Relevant to Friction Stir Welding Condition


13. Fracture and Fatigue of Lightweight Alloys for Energy Storage


14. Ultra-high Temperature Metallic Glasses

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 the Cleveland 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: http://www.fortwaynemetals.com )

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

For more information:

Conference Posters:

• Neural Interfaces Conference 2008 poster
• Research ShowCASE 2008 poster
• IFESS 2007 poster
• Research ShowCASE 2007 poster
• Research ShowCASE 2006 poster

Journal Papers:

• Fracture and Fatigue of Implantable 316LVM 1x7 cable
• Fracture and Fatigue of Implantable Composite DFT cables

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.

Conference Posters:

• Mechanical Properties of Aluminium Based Amorphous Alloy Ribbons

3. 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.

Conference Posters:

• Effect of composition on mechanical properties of Fe based amorphous ribbon
• Fracture and Fatigue of Fe based metallic glass ribbon

4. 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.

Conference Posters:

• Intrinsic and Extrinsic toughening of BMGs
• Temperature and Loading Rate effects on the Mechanical Behavior of Ca based BMG

Journal Papers:

• Chemistry (Intrinsic) and Inclusion (Extrinsic) Effects on the Toughness and Weibull Modulus of Fe-Based Bulk Metallic Glasses

5. 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.

Conference Posters:

• Toughness of Nano- Crystalline Aluminium Alloy Composites

Journal Papers:

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

6. 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.

• Dynamic Compression Behavior of Zr and Fe based BMG
• Shock Response of a Zr based BMG

Journal Papers:

• Design of Inserts for Split-Hopkinson Pressure Bar Testing
• Effect of High Strain Rates on Peak Stress in Zr based BMG
• Effects of Annealing and Specimen Geometry on Dynamic Compression of Zr based BMG
• Spall Strength of Zr based BMG under Shock Induced Compression and Shear Loading

7.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.

• Deformation and Fracture of Advanced Aerospace Materials

8. 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.

Conference Posters:

• Fatigue and Toughness of Niobium-Silicon Alloys

9. 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.

Journal Papers:

• Thermal Exposure and Test Temp effects on Structural evolution and Hardness/Viscosity of Fe based BMG

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

Journal Papers:

• Tough Fe based Bulk Metallic Glass
• Chemistry (Intrinsic) and Inclusion (Extrinsic) Effects on the Toughness and Weibull Modulus of Fe-Based Bulk Metallic Glasses

11. Effects of Sensitization 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 high strain rate conditions. Microstructural changes are being documented using TEM on both annealed and service-exposed materials while fracture toughness and high strain rate studies are also being conducted in conjunction with Prof. Vikas Prakash, Mechanical and Aerospace Engineering Department, on both as-received and service-exposed materials.

Conference Posters:

• Sensitization Effects on the Microstructure and Mechanical Properties of 5xxx Aluminium Alloys
• Microstructure and Mechanical Properties Evolution of Long-Time Serviced 5xxx Aluminium Alloys

12. 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

13. Fracture and Faigue 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.

14. 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.