Silicon mechanical behavior

Recent work has focused on a variety of thermoplastic elastomers and modified thermoplastic polyimides based on the aminopropyl end functionality present in suitably equilibrated polydimethylsiloxanes. Characteristic of these are the urea linked materials described in references 22-25. The chemistry is summarized in Scheme 7. A characteristic stress-strain curve and dynamic mechanical behavior for the urea linked systems in provided in Figures 3 and 4. It was of interest to note that the ultimate properties of the soluble, processible, urea linked copolymers were equivalent to some of the best silica reinforced, chemically crosslinked, silicone rubber... 

A. -B. Chen, A. Sher and W. T. Yost, Elastic Constants and Related Properties of Semiconductor Compounds and Their Alloys D. R. Clarke, Fracture of Silicon and Other Semiconductors H. Siethoff, The Plasticity of Elemental and Compound Semiconductors S. Guruswamy, K. T. Faber and J. P. Hirth, Mechanical Behavior of Compound Semiconductors... 

Becher PF, Lin HAT, Hwang SL, Hoffmann MJ, Chen IW (1993) The influence of microstructure on the mechanical behavior of silicon nitride ceramics. In Chen IW, Becher P, Mitomo M, Petzow G, Yen TS (eds) Silicon Nitride Ceramics-Scientific and Technological Advances. MRS Symposium Proc 287, MRS Pittsburgh, p 147... 

Rouxel, T., High temperature mechanical behavior of silicon nitride ceramics, J. Ceram. Soc. Jap., 109(6) 89-98 (2001). 

The first three items relate to the chemical nature of the film. An outstanding feature of PECVD silicon nitride films is that their stoichiometry can be controlled, and that they can have as much as 30 atomic percent hydrogen in them. The last two items relate to the mechanical behavior of such films. If they are not dense enough, they will net be effective barriers to moisture... 

It can be seen from Fig.3 that chromium films differ from molybdenum films in the mechanical behavior essentially. So, unloading curve for chromium at depth about 330 nm shows displacement discontinuity that, as is known, testifies to phase transition in silicon under loading (a metal phase of high pressure Si II [6]). On unloading curve for molybdenum the phase transition in silicon is not fixed. Besides average contact pressure in molybdenum film is lower, than in a chromium film more than in 2 times and this distinction increases with reduction of depth of contact. 

Silicon (Si) with an atomic number of 14 is a covalent material with wide-ranging application as a semiconductor in industry in devices and solar panels. Here our interest is primarily limited to the structure of amorphous Si and its mechanical behavior in its glassy range. In its crystalline form Si has a diamond-cubic structure with an atomic coordination number of 4 and has a relatively low density of Po = 2330 kg/m at room temperature. The diamond-cubic crystal structure of Si, for purposes of crystal plasticity, acts very similarly to fee metals and has most of the deformation characteristics of the fee structure. These characteristics, which have been studied intensively, are of no interest here. A summary of the low-temperature crystal plasticity of crystalline Si can be found elsewhere (Argon 2008). 

N. P. Bansal, Mechanical Behavior of Silicon Carbide Fiber-Reinforced Strontium Aluminosilicate Glass-Ceramic Composites, Mater. Sci. Eng. A, 231 [1—2] 117—127 (1997). 

IN-SITU REACTION SINTERING OF POROUS MULLITE-BONDED SILICON CARBIDE, ITS MECHANICAL BEHAVIOR AND HIGH TEMPERATURE APPLICATIONS... 

In-Situ Reaction Sintering of Porous Mullite-Bonded Silicon Carbide, 127 Its Mechanical Behavior and High Temperature Applications Neelkanth Bardhan and Parag Bhargava... 

G. Simon, Mechanical behavior and structure of the silicon carbide Nicalon fiber, PhD Thesis, ENS Mines Paris, January 11,1984. 

Electrical Transport in Porous Silicon ), and mechanical behavior ( Mechanical Properties of Porous Silicon ). 

TAILORING THE COMPOSITION OF SELF-REINFORCED SILICON NITRIDE CERAMICS TO ENHANCE MECHANICAL BEHAVIOR... 

J. Perez Rigueiro, J. Y. Pastor, J. Llorca, M. Elices, P. Miranzo, and J. S. Moya, Revisiting the Mechanical Behavior of Alumina/Silicon Carbide Nanocomposites, Acta Mater., 46, 5399 5411 (1998). 

We will now consider the viscoelastic properties of silicone gels with a mechanical model. It is possible to express complex mechanical behaviors by properly connecting a spring and dashpot, which are the mechanical models for modulus and viscosity, respectively. The Maxwell model, which is the model to connect a spring and dashpot in series, continues to deform upon application of external force. It is therefore liquidlike and is convenient to express the mechanical properties of a sol, which has elastic properties. In contrast, the Voigt model, which is the model to connect a spring and dashpot in parallel, reaches a finite deformation and exhibits equilibrium. Hence, it is solidlike and is convenient to express a gel that shows loss in mechanical energy [201]. 

In order to determine the viscoelastic properties of silicone gel materials, vibrational measurement techniques are used. The principle of vibrational measurement techniques involves determining die viscoelastic quantities by observing the responding mechanical behavior when cyclic deformation is applied repeatedly. Dynamic viscoelastic property measurements are performed with a dynamic mechanical spectrometer such as the RDA-II from Rheometrics. This instrument measures the complex modulus G and loss factor tan S from the torque measured by the transducer equipped at the upper portion of the sample chamber when shear deformation is applied to the sample at a specified shear strain and frequency from the actuator at the bottom of the sample chamber. 

A. Chu, H. M. Chan and M. P. Harmer, Effect of Annealing Environment on the Crack Healing and Mechanical Behavior of Silicon Carbide-Reinforced Alumina Nanocomposite, J. Am. Ceram. Soc., 81, 1203-208 (1998). 

---