Silicon deformation

P. Omling, E. R. Weber, L. Montelius, H. Alexander and J. Michel, Electrical properties of dislocations and point defects in plastically deformed silicon , Phys. Rev. B, 32, 6571 (1985). 

This superplastically deformed silicon nitride also showed substantially improved creep resistance at high temperatures, when the stress was applied along the extruding direction. For example, the creep rates of the deformed body in tensile creep tests conducted at 1200 °C was found to be about one order of magnitude lower... 

Figure 8.12 Original and superplastically deformed silicon nitride specimens and their microstructures. In the deformed specimen, manyofthe fibrous grains are aligned alongthe...

In the absence of cavitation, creep in vitreous-bonded materials would occur by S-P, wherein material dissolves from one side of the grain and deposits on another [48, 49]. No definitive studies have been made to date that support the dislocation creep models in which the grains of silicon nitride deform by dislocation motion. Studies of deformed silicon nitride grains have provided no evidence of the types of dislocation pileup that should be present in order for this type of mechanism to be active [50]. 

Fig. 17. Photoluminescence spectra of deformed silicon, (a) At room temperature, under 5 GPa and (b) at 150 °C, under 5 GPa. After Pizzini et al. [81]. See text for detail.

Fig. 18. Photoluminescence spectra of deformed silicon anneaUng effects. See text for detail. After...

The relationship between the increase in contact radius due to plastic deformation and the corresponding increase in the force required to detach submicrometer polystyrene latex particles from a silicon substrate was determined by Krishnan et al. [108]. In that study, Krishnan measured the increase in the contact area of the partieles over a period of time (Fig. 7a) and the corresponding decrease in the percentage of particles that could be removed using a force that was sufficient to remove virtually all the particles initially (Fig. 7b). 

Ceramic materials are typically noncrystalline inorganic oxides prepared by heat-treatment of a powder and have a network structure. They include many silicate minerals, such as quartz (silicon dioxide, which has the empirical formula SiO,), and high-temperature superconductors (Box 5.2). Ceramic materials have great strength and stability, because covalent bonds must be broken to cause any deformation in the crystal. As a result, ceramic materials under physical stress tend to shatter rather than bend. Section 14.22 contains further information on the properties of ceramic materials. 

Due to particles extrusion, crystal lattice deformation expands to the adjacent area, though the deformation strength reduces gradually (Figs. 10(a)-10(other hand, after impacting, the particle may retain to plow the surface for a short distance to exhaust the kinetic energy of the particle. As a result, parts of the free atoms break apart from the substrate and pile up as atom clusters before the particle. The observation is consistent with results of molecular dynamics simulation of the nanometric cutting of silicon [15] and collision of the nanoparticle with the solid surface [16]. 

When particle impacts with a solid surface, the atoms of the surface layer undergo crystal lattice deformation, and then form an atom pileup on the outlet of the impacted region. With the increase of the collision time, more craters present on the solid surface, and amorphous transition of silicon and a few crystal grains can be found in the subsurface. 

The cross section of the collision region that the particle impacts with the Si surface with an incident angle of 45° at a speed of 2,100 m/s is shown in Fig. 16 [28]. As the particle impacts into the Si surface layer, the contact region of the Si surface layer transforms from crystal into amorphous phase immediately. The area of the depressed region and the thickness of the amorphous layer increase with the penetration depth of the particle (Figs. 16(a)-16(c)). After it reaches the deepest position, the particle then moves both upwards and rightwards, and some silicon atoms ahead of the particle are extruded out and result in a pileup of atoms. Then the released elastic deformation energy of the Si surface pushes... 

FIGURE 26.9 Newton s interference fringes formed between a glass plate lubricated with a silicon oil film and a mbber sphere sliding on it, showing the deformation of the sphere through the hydrodynamic pressure exerted on the mbber sphere. (From Roberts, A.D., The Physics of Tire Traction, Theory and Experiment, Hayes, D.L. and Browne, A.L. (eds.). Plenum Press, New York/London, 1974.)... 

A plugging material with 2-furaldehyde-acetone monomer and silicone oligomers has been described [1099]. The components for this material are shown in Table 18-1. The 2-furaldehyde-acetone monomer can contain mono-furfurylidene-acetone and difurfurylidene-acetone. The hardener can be iron chloride, benzene-sulfonic acid, hexamethylene diamine, or polyethylene polyamine. The plugging stone has improved strength, elastic-deformation, and anticorrosion and adhesion properties. 

Fig. 1.18 A film of silicone oil of 1 mm thickness is flowing along a vertically oriented planer sheet of PMMA. In a tagging experiment, a horizontal slice of 2 mm thickness is marked and its deformation is recorded as a function of the separation time A between the...

The performance of such a probe can be demonstrated for polymer studies by heating a phantom sample up to 460 °C. The sample was made from a PTFE plug, two pieces of a PVC hose and a silicon rubber hose. The deformation and the... 

---