The Fracture Behaviour of Hot-Pressed Silicon Nitride between Room Temperature and 1400°C

1983 ◽  
pp. 523-528 ◽  
Author(s):  
Karel Kříž
1990 ◽  
Vol 201 ◽  
Author(s):  
Honglie Shen ◽  
Genqing Yang ◽  
Zuyao Zhou ◽  
Guanqun Xia ◽  
Shichang Zou

AbstractDual implantations of Si+ and P+ into InP:Fe were performed both at 200°C and room temperature. Si+ ions were implanted by 150keV with doses ranging from 5×1013 /cm2 to 1×1015 /cm2, while P+ ions were implanted by 110keV. 160keV and 180keV with doses ranging from 1×l013 /cm2 to 1×1015 /cm2. Hall measurements and photoluminescence spectra were used to characterize the silicon nitride encapsulated annealed samples. It was found that enhanced activation can be obtained by Si+ and P+ dual implantations. The optimal condition for dual implantations is that the atomic distribution of implanted P overlaps that of implanted si with the same implant dose. For a dose of 5×l014 /cm2, the highest activation for dual implants is 70% while the activation for single implant is 40% after annealing at 750°C for 15 minutes. PL spectrum measurement was carried out at temperatures from 11K to 100K. A broad band at about 1.26eV was found in Si+ implanted samples, of which the intensity increased with increasing of the Si dose and decreased with increasing of the co-implant P+ dose. The temperature dependence of the broad band showed that it is a complex (Vp-Sip) related band. All these results indicate that silicon is an amphoteric species in InP.


1992 ◽  
Vol 287 ◽  
Author(s):  
T.S. Yen ◽  
W.Y. Sun

ABSTRACTAdditions and revisions to several of the most important phase diagrams and phase behavior diagrams in the silicon nitride field are reviewed in this work, with emphasis on the Y-Si-A1-O-N system. This information is further used to make observations on the promising silicon nitride systems containing either highly refractory grain boundary phases or compatible matrix phases of desirable properties. Examples are provided to illustrate the advantage of such a basic approach to materials design. Hardness, toughness, strength at room temperature and elevated temperature and even sinterability can all be improved by adopting such an approach.


2003 ◽  
Vol 212-213 ◽  
pp. 388-392 ◽  
Author(s):  
Marcus A Pereira ◽  
José A Diniz ◽  
Ioshiaki Doi ◽  
Jacobus W Swart

1992 ◽  
Vol 286 ◽  
Author(s):  
Lide Zhang ◽  
Chimei Mo ◽  
Tao Wang ◽  
Cunyi Xie

ABSTRACTNanostructured silicon nitride solids (NANO–SSNS) were investigated by x–ray photoelectron spectroscopy (XPS), electron spin resonance (ESR) and dielectric measurements. It is found that the dielectric constant of NANO–SSNS depends strongly on the measuring frequency, f. When f<100Hz, at room temperature it is forty times as much as that of conventional Si3N4. ESR measurements show that a large number of unbinding electrons exist in interfaces. This suggests that the NANO–SSNS possess strong polarity. The study on the bond properties indicates that a large number of unsaturated and dangling bonds exist in interfaces of NANO–SSNS.


1969 ◽  
Vol 4 (2) ◽  
pp. 81-87 ◽  
Author(s):  
E K Priddle

This work describes the fracture behaviour of silicon-carbide tubular specimens under multi-axial stresses at room temperature. A method of obtaining combinations of stresses in the form of torsion, hoop, axial tension, and compression is described and failure envelopes for silicon carbide are included from the data obtained. Failure theories are reviewed and the results from the work show that the available theories are inadequate to describe both the tension-tension and tension-compression quadrants. For practical purposes a straight-line relation can be used joining axial and hoop tensile strengths and the axial compression strength.


2015 ◽  
Vol 1087 ◽  
pp. 6-10
Author(s):  
Mohd Azham Azmi ◽  
Sufiah Mohamad Yahya ◽  
Sufizar Ahmad ◽  
Hariati Taib

The focus of this study is to investigate the mechanical properties and fracture behaviour of polydimethylsiloxane filled crystalline silica composites (PDMS/CS) upon tensile loading. The PDMS/CS composites were fabricated by using casting method and cured at room temperature for 24 hours. Crystalline silica (CS) were added to PDMS at compositions of 2, 6, 10 wt%. The tensile properties of PDMS/2wt%CS showed that the tensile stress were improved by 4.3%. Fracture behaviour as determined by the characteristic of fracture surface of pure PDMS and PDMS/CS composites were analysed using Field Emission Scanning Electron Microscopy (FESEM) and Atomic Force Microscopy (AFM). Observation via FESEM and AFM indicated different fracture characteristic of filled PDMS and unfilled PDMS. The addition of CS as fillers were indeed proven to improve the strength of the composites.


1992 ◽  
Vol 284 ◽  
Author(s):  
C. Savall ◽  
E. Bustarret ◽  
J. P. Stoquert ◽  
J. C. Bruyére

ABSTRACTWe present the changes upon isochronous annealing in the room temperature photoluminescence (PL) spectra of nearly stoichiometric silicon nitride. Samples are prepared by the 50kHz PECVD of a N2/SiH4/Helium gas mixture at 350°C. In the as-deposited films the hydrogen content was around 11% for a refractive index of 1.98. For a photoexcitation at 351 nm, the polarized PL spectrum of the as-deposited film is characterized by a main broad emission band in the visible region with a maximum at 2.55eV. A second narrow peak (FWHM = 55meV), at 3.02eV is observed. We study the evolution of the PL spectra with different isochronous anneals from 350°C to 1000°C. Even though the general shape of the PL spectra does not change, we observe an increase of quantum efficiency with maximum value upon 750°C annealing. Beyond this temperature the low energy part of the PL spectrum shows a slight increase. These variations are compared to those of the infrared absorption peaks measured on the same samples. Both the temperature dependence of the intensity of a well defined absorption peak in the Si-H stretching mode region and that of the PL features can be explained assuming that solid state chemical reactions involving hydrogen and Si-Si bonds occur in the bulk of the alloy.


Sign in / Sign up

Export Citation Format

Share Document