Grinding bodies from silicon nitride for fine milling of ceramic materials

1992 ◽  
Vol 49 (5) ◽  
pp. 239-240
Author(s):  
B. I. Kislov ◽  
L. V. Vodop'yanova
Keyword(s):  
Silicon Nitride ◽  
Ceramic Materials ◽  
Fine Milling

Examination of Fracture Interfaces in Silicon Nitride

1975 ◽  
Vol 33 ◽  
pp. 60-61
Author(s):  
Nancy J. Tighe
Keyword(s):  
Silicon Nitride ◽  
Grain Boundary ◽  
Crack Growth ◽  
Subcritical Crack Growth ◽  
Slow Crack Growth ◽  
Ceramic Materials ◽  
Grain Boundary Sliding ◽  
Boundary Phase ◽  
Turbine Engines ◽  
Boundary Sliding

Silicon nitride is one of the ceramic materials being considered for the components in gas turbine engines which will be exposed to temperatures of 1000 to 1400°C. Test specimens from hot-pressed billets exhibit flexural strengths of approximately 50 MN/m2 at 1000°C. However, the strength degrades rapidly to less than 20 MN/m2 at 1400°C. The strength degradition is attributed to subcritical crack growth phenomena evidenced by a stress rate dependence of the flexural strength and the stress intensity factor. This phenomena is termed slow crack growth and is associated with the onset of plastic deformation at the crack tip. Lange attributed the subcritical crack growth tb a glassy silicate grain boundary phase which decreased in viscosity with increased temperature and permitted a form of grain boundary sliding to occur.

Layer thickness optimization of ceramic composite for body armor by considering volume, weight, and cost

2021 ◽  
pp. 095440622110157
Author(s):  
Yuksel Palaci ◽  
Mustafa M Arikan
Keyword(s):  
Silicon Nitride ◽  
Boron Carbide ◽  
Layer Thickness ◽  
Ceramic Composite ◽  
Material Selection ◽  
Composite Layer ◽  
Ceramic Materials ◽  
Ternary Diagram ◽  
Body Armor ◽  
Volume Weight

This study investigates visualization of optimized layer thickness with a ternary diagram by considering Volume, Weight, and Cost priorities to determine the composite structure of alternative ceramics to use in body armor application by using the Digital Logic Method (DLM). Three criterion priorities (volume, weight, cost) have been investigated to help designers decide on optimum ceramic material for their applications. Alumina (Al2O3), silicon carbide (SiC), silicon nitride (Si3N4), and boron carbide (B4C) were analyzed and ranked to decide for material selection based on priorities. The analysis results showed that silicon nitride (Si3N4) had the maximum performance index (PI) point (80.0) based on the volume priority. On the other hand, while boron carbide (B4C) had the maximum PI point (76.4) in terms of the weight priority, alumina (Al2O3) was determined to be the best material according to the cost priority. PI point of alumina (Al2O3) was calculated as 100. A ternary diagram was developed for decision-makers to visualize material selection performances. The optimization of the ceramic composite layer thickness of the alternative ceramic materials is visualized by considering three criteria.

Short term tribological behavior of ceramic and polyethylene biomaterials for hip prosthesis

2021 ◽  
Vol 63 (5) ◽  
pp. 470-473
Author(s):  
Subramaniam Shankar ◽  
Rajavel Nithyaprakash ◽  
Balasubramaniam Rajasulochana Santhosh
Keyword(s):  
Silicon Nitride ◽  
Friction And Wear ◽  
Hip Prosthesis ◽  
Tribological Behavior ◽  
Ceramic Materials ◽  
Blood Stream ◽  
Wear Characteristics ◽  
Polyether Ether Ketone ◽  
Spherical Ball ◽  
Pin On Disc

Abstract Reduction in wear of artificial bio-implants results in the release of a lesser amount of wear particles into the blood stream. This paper focuses on analyzing the tribological behavior of ceramic and polyethylene bio-materials experimentally. Four different biomaterials namely Zirconia, Silicon Nitride, UHMWPE (ultra high molecular weight polyethylene) and PEEK (polyether ether ketone) are investigated for friction and wear coefficients using a pin on disc (PoD) tribometer. Alumina (Al2O3) is chosen as the disc material. Polyethylene based UHMWPE and PEEK are used as a pin material with the hemispherical end, while, Zirconia and Silicon Nitride ceramic materials are used in the form of spherical ball. 0.9 % NaCl (saline solution) is used as a lubricant medium. Zirconia showed a better reduction in friction and wear coefficient characteristics under lubrication conditions when compared with polyethylene and other ceramic materials. The estimated friction and wear coefficients would be helpful for surgeons and academicians to choose better wear-resistant bio-compatible materials for effectively design hip prosthesis. The present study compared the tribological behaviors of ceramic materials Si3N4 and ZrO2 and polyethylene materials PEEK and UHMWPE with a ceramic counterpart Al2O3 disc. In the lubrication case, ZrO2 showed a better reduction in friction and wear characteristics while in the dry case UHMWPE showed lesser wear characteristics.

scholarly journals An Evaluation of Indentation and Finishing Properties of Bearing Grade Silicon Nitrides

1995 ◽  
Author(s):  
James F. Dill ◽  
Michael N. Gardos ◽  
Robert G. Hardisty
Keyword(s):  
Fracture Toughness ◽  
Silicon Nitride ◽  
Ceramic Materials ◽  
Initial Study ◽  
Indentation Hardness ◽  
Simple Relationship ◽  
Machining Performance ◽  
General Applicability ◽  
Load Dependence ◽  
Time Required

This paper describes the results of studies of the machining performance and the indentation hardness and fracture toughness of different silicon nitride materials as part of an effort to better define the optimum machining conditions for bearing components. This work builds on prior efforts by two of the authors, Gardos and Hardisty (1993) who formulated a simple relationship between diamond grinding performance of silicon nitride bearing balls and a wear equation first detailed by Evans and Wilshaw (1976). The goal of this present work was to determine the general applicability of such a relationship, i.e. could simple indentation studies be used to define finishing conditions for different silicon nitride materials. The availability of such a simple test would reduce the time required for developing an acceptable process when a supplier changes his formulation, or when a new material becomes available. Quicker development of optimum finishing conditions would eventually result in a lower-cost product for users. The initial study by Gardos and Hardisty (1993) was based on limited data taken at a fixed set of conditions. This study expanded the range of conditions evaluated and the number of ceramic materials studied in an effort to define the universality of the relationship between grinding wear, hardness and toughness. This study has shown that no simple relationship like that first envisioned by the authors exists. The results showed that the grinding wear of the individual silicon nitride materials increased at different rates as a function of load. Because of the differences found in the load dependence of grinding rates, no simple relationship between hardness, fracture toughness and grinding rate could be found which fit the data over the range of conditions studied. This work is part of an ARPA funded effort to provide a tribological performance database on ceramic bearing materials, including their grinding and finishing properties, and their interaction with standard bearing steels.

Corrosion of engineering ceramic materials by molten iron part I: Silicon nitride and SiAlON

2016 ◽  
Vol 107 ◽  
pp. 76-84 ◽  
Author(s):  
M. Hnatko ◽  
M. Tatarková ◽  
D. Galusková ◽  
R. Bystrický ◽  
Z. Lenčéš ◽  
...  
Keyword(s):  
Silicon Nitride ◽  
Ceramic Materials ◽  
Molten Iron ◽  
Iron Part ◽  
Engineering Ceramic

Silicon Nitride—From Powder Synthesis to Ceramic Materials

1991 ◽  
Vol 30 (12) ◽  
pp. 1579-1597 ◽  
Author(s):  
Horst Lange ◽  
Gerhard Wötting ◽  
Gerhard Winter
Keyword(s):  
Silicon Nitride ◽  
Ceramic Materials ◽  
Powder Synthesis

Quantitative Phase Analysis of Synthetic Silicon Nitride by X-Ray Diffraction

1979 ◽  
Vol 23 ◽  
pp. 375-379
Author(s):  
Z. Mencik ◽  
M. A. Short ◽  
C. R. Peters
Keyword(s):  
Silicon Nitride ◽  
Phase Analysis ◽  
Gas Turbines ◽  
Ceramic Materials ◽  
Silicon Oxynitride ◽  
Quantitative Phase Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Quantitative Phase ◽  
Typical Material

Synthetically prepared silicon nitride is one of the more promising ceramic materials for structural components of gas turbines. Typical material may contain a-silicon nitride, Si3N4 (which is believed to always contain oxygen and therefore, according to Grievson, Jack and Wild, is more properly written as Si11.5N15O0.5), β-silicon nitride, Si3N4, silicon oxynitride, Si2ON2, silicon metal, Si, and α-cristobalite, SiO2. Because the physical properties of the ceramic parts are dependent on their phase composition, it is essential that a technique be available for performing a phase analysis. An X-ray diffraction procedure has been, developed for the quantitative phase analysis of synthetically prepared silicon nitride. This procedure converts experimentally measured intensities of selected X-ray diffraction peaks to weight fractions of components using empirically determined intensity coefficients.

SILICON NITRIDE CERAMIC MATERIALS FOR AVIATION GTE BEARINGS AND METHODS OF MANUFACTURING (review)

2019 ◽  
pp. 42-49
Author(s):  
I.O. Belyachenkov ◽  
◽  
N.E. Schegoleva ◽  
A.S. Chainikova ◽  
M.L. Vaganova ◽  
...  
Keyword(s):  
Silicon Nitride ◽  
Ceramic Materials ◽  
Silicon Nitride Ceramic
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