MTS Systems Corporation

About: MTS Systems Corporation is a company organization based out in Eden Prairie, Minnesota, United States. It is known for research contribution in the topics: Signal & Actuator. The organization has 448 authors who have published 524 publications receiving 13897 citations.

Measurement of hardness and elastic modulus by instrumented indentation: Advances in understanding and refinements to methodology

Abstract: The method we introduced in 1992 for measuring hardness and elastic modulus by instrumented indentation techniques has widely been adopted and used in the characterization of small-scale mechanical behavior. Since its original development, the method has undergone numerous refinements and changes brought about by improvements to testing equipment and techniques as well as from advances in our understanding of the mechanics of elastic–plastic contact. Here, we review our current understanding of the mechanics governing elastic–plastic indentation as they pertain to load and depth-sensing indentation testing of monolithic materials and provide an update of how we now implement the method to make the most accurate mechanical property measurements. The limitations of the method are also discussed.

Indentation power-law creep of high-purity indium

Abstract: Using a variety of depth-sensing indentation techniques, the creep response of high-purity indium, from room temperature to 75 °C, was measured. The dependence of the hardness on the variables of indentation strain rate (stress exponent for creep (n)) and temperature (apparent activation energy for creep (Q)) and the existence of a steady-state behavior in an indentation test with a Berkovich indenter were investigated. It was shown for the first time that the indentation strain rate (-este-/h) could be held constant during an experiment using a Berkovich indenter, by maintaining the loading rate divided by the load (-este-/P) constant. The apparent activation energy for indentation creep was found to be 78 kJ/mol, in accord with the activation energy for self-diffusion in the material. Finally, by performing -este-/P change experiments, it was shown that a steady-state path independent of hardness could be reached in an indentation test with a geometrically similar indenter.

Influence of indenter tip geometry on elastic deformation during nanoindentation

Abstract: Nanoindentation with a Berkovich indenter is commonly used to investigate the mechanical behavior of small volumes of materials. To date, most investigators have made the simplifying assumption that the tip is spherical. In reality, indenter tips are much more complex. Here, we develop a new method to describe the tip shape using the experimentally determined area function of the indenter at small depths (0--100 nm). Our analysis accurately predicts the elastic load-displacement curve and allows the theoretical strength of a material to be determined from pop-in data. Application of our new method to single crystal ${\mathrm{Cr}}_{3}\mathrm{Si}$ shows that the predicted theoretical strengths are within 12% of the ideal strength $G/2\ensuremath{\pi}$, where $G$ is the shear modulus.

Lasers and Electro-optics

Abstract: 1. Electromagnetic waves, light, and lasers 2. Optical frequency amplifiers 3. Introduction to two practical laser systems 4. Optical resonators containing amplifying media 5. Laser radiation 6. Control of laser oscillators 7. Optically pumped solid-state lasers 8. Gas lasers 9. Molecular gas lasers I 10. Molecular gas lasers II 11. Tunable lasers 12. Semiconductor lasers 13. Passive optical systems 14. Periodic optical systems, resonators and inhomogenous media 15. Optics of Gaussian beams 16. Optical fibers and waveguides 17. Optics of anisotropic media 18. The electro-optic and acousto-optic effects and modulation of light beams 19. Introduction to nonlinear processes 20. Wave propagation in nonlinear media 21. Detection of optical radiation 22. Coherence theory 23. Laser applications Index.