# Presentation: 646050

## “Bridging Length Scales in Deforming Single and Textured Polycrystals of Structural Magnetic Shape Memory Alloys (MSMAs)”I. Karaman and D. C. Lagoudas, Texas A&M University, DMR- 0244126

**“****Bridging Length Scales in Deforming Single and Textured Polycrystals of Structural Magnetic Shape Memory Alloys (MSMAs)”****I. Karaman and D. C. Lagoudas, Texas A&M University, DMR- 0244126**

**Motivation**

- Engineer the compositions and microstructure of selected FeNiCo and CoNi(Al,Ga) alloys to obtain MSMAs with high saturation magnetization and magnetocrystalline anisotropy energy.
- Investigate magneto-thermo-mechanical behavior of selected MSMAs in single and textured polycrystalline forms to reveal the governing mechanisms.
- Fabricate textured polycrystals utilizing consolidation under magnetic field
- Develop a thermodynamically sound model that will consider hysteresis effects, texture and the coupling temperature, stress and magnetic field effects on MSM.
- Tools

**Experimental Results**

- Constitutive model based on Gibbs free energy expression which includes magnetic energy terms and dissipative effects introduced through internal state variables, which are physically motivated by magnetic and crystallographic microstructure
- Numerical predictions of reorientation strain-magnetic field-hysteresis curves for different applied stress values in NiMnGa

- Development of compositions that resulted in wide temperature range in which pseudoelasticity observed (-100 C to 200 C), high strength and up to 5 % recoverable shape change, very low thermal and stress hysteresis as compared to NiTi, and ***magnetic field induced strain as high as 5%***.

**Modeling Results**

- Powder consolidation using Equal Channel Angular Extrusion under magnetic field

- In-house built magneto thermo mechanical testing set-up

**“****Bridging Length Scales in Deforming Single and Textured Polycrystals of Structural Magnetic Shape Memory Alloys (MSMAs)”****I. Karaman and D. C. Lagoudas, Texas A&M University, DMR- 0244126**

**Broad Impact**

- Publication of four manuscripts (*Scripta Materialia*,Vol. 51, 261-266 (2004), *Scripta Materialia*, Vol. 49, 831-838 (2003), one submitted to *Philosophical Magazine A*, *Smart Structures and Materials* 2004 Conference Proceedings).
- Collaboration with Prof. Hans J. Maier of University of Paderborn, Germany and  Prof. Yuriy I. Chumlyakov and Dr. I. Kireeva of Siberian Physical-Technical Institute, Russia. Mutual visits between collaborators.
- Collaboration with Dr. Yang Ren of Advanced Photon Source, Argonne National Laboratory. One graduate and one undergraduate student will visit ANL in November.
-  Undergraduate student exchange program between University of Paderborn (UP), Germany and Texas A&M University.
**Education**
-  Three graduate (one female) and six undergraduate (two female, one asian-american) students were involved in this work.

-  One of the undergraduate students (Joseph Mather) is currently a PhD student at UIUC. A conference paper is presented together with undergraduate students
- Two graduate students attended international conferences and one visited UP to work with German graduate students
-  Close collaboration with Harmony Science Academy (HSA) (K-12 charter school with 60% hispanic and 20% African-American student body).
- Five middle and high school students (two female, two hispanic, one african-american, one asian-american) prepared science projects and got several awards.
- Shape memory alloys have been incorporated into an art class by Ms. Alcorn of HSA.

- Taylor Towns (K-9) conducting experiments on Smart Springs

- Alexander Galit (K-9) is with his poster on “Smart Materials Never Forget”

- Tiffany Tiemann (junior UG) is conducting DSC
- experiments on CoNiGa alloys

**Collaboration with High Schools **

## Collaboration with High Schools

| SCIENCE AND ENGINEERING FAIR OF HOUSTON 2004 |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- |
| Name | School  | Project Title | Category |  | Awarding Agency | Rank | Supervisor |
| Malhissa Reyes | Harmony Science Academy | Shape Memory Alloys | Junior-Engineering |  | American Society for Materials | 2nd  | Dr. Ibrahim Karaman |
| Alexander Galit | Harmony Science Academy | Smart Materials Never Forget | 9th – Engineering |  | American Society of Materials | 1st | Dr. Ibrahim
Karaman |
| Marnesar Javier | Harmony Science Academy | Smart Springs  | 9th-Engineering |  | Texas Society of Professional Engineers | 1st | Dr. Ibrahim Karaman |
| Marnesar Javier | Harmony Science Academy | Smart Springs  | 9th-Engineering |  | American Society of Indian Engineers | 1st | Dr. Ibrahim Karaman |
| Marnesar Javier | Harmony Science Academy | Smart Springs  | 9th-Engineering |  | M.I.T. Club of South texas | 1st | Dr. Ibrahim Karaman |
| Marnesar Javier | Harmony Science Academy | Smart Springs  | 9th-Engineering |  | University of Houston Engineering Alumni Association | 1st | Dr. Ibrahim Karaman |
| Nathan Colbert | Harmony Science Academy | Liquid Metals  | Junior-Engineering |  | American Society for Materials | 1st | Dr. Ibrahim Karaman |
| TEXAS JUNIOR ACADEMY OF SCIENCE 2004 (at Texas A&M) |  |  |  |  |  |  |  |
| Name | School  | Project Title | Category | Rank |  |  | Supervisor |
| Marnesar Javier | Harmony Science Academy | Smart Springs  | Engineering | Honorable Mention |  |  | Dr. Ibrahim Karaman |
| AUSTIN REGIONAL SCIENCE FAIR  |  |  |  |  |  |  |  |
| Name | School  | Project Title | Category | Rank |  |  | Supervisor |
| Taylor Towns | Austin Science Academy | Smart Springs | Engineering | 4th Place |  |  | Dr. Ibrahim Karaman |

**“****Bridging Length Scales in Deforming Single and Textured Polycrystals of Structural Magnetic Shape Memory Alloys (MSMAs)”****I. Karaman and D. C. Lagoudas, Texas A&M University, DMR- 0244126**