scholarly journals Tensile Test of Sintered Silicon Nitride Ceramic at Elevated Temperatures

1991 ◽  
Vol 34 (3) ◽  
pp. 351-360
Author(s):  
Kenji HATANAKA ◽  
Hirohisa SHIOTA ◽  
Takayuki ANDO
Keyword(s):  
Silicon Nitride ◽  
Tensile Test ◽  
Elevated Temperatures ◽  
Silicon Nitride Ceramic ◽  
Sintered Silicon

scholarly journals Experiment on Foreign Object Damage of Gas Turbine-Grade Silicon Nitride Ceramic

1998 ◽  
Author(s):  
Hiro Yoshida ◽  
Takashi Nakashima ◽  
Makoto Yoshida ◽  
Yasushi Hara ◽  
Toru Shimamori
Keyword(s):  
Elevated Temperature ◽  
Silicon Nitride ◽  
Elevated Temperatures ◽  
Tensile Load ◽  
Strength Degradation ◽  
Spall Fracture ◽  
Silicon Nitride Ceramic ◽  
Impact Tests ◽  
The Impact ◽  
Bending Fracture

A new high quality turbine system using monolithic silicon-nitride ceramic is under development. In this study particle impact tests of the silicon-nitride have been tried at room and elevated temperatures with and without tensile load, which simulates centrifugal force of blade rotation. In the experiment 1 mm diameter particle is impacted at velocities up to 900 m s−1. In this paper, critical velocities for bending fracture and Hertzian cracks are examined. Moreover, strength degradation at elevated temperature and spall fracture of the blade are discussed. The main results are: 1) The bending fracture mode critical impact velocity for soft particles is higher than that for hard particles. 2)The impact parameter ϕ for initiation of Hertzian cracks ranges 1.08×10−5 – 1.56×10−5 for the materials tested. 3)Strength degradation at elevated temperature was clearly observed. 4) In the impact tests on blades spall fracture, which was caused by interaction of stress waves, appeared.

Impact Fracture Behavior of Turbine-Grade Silicon Nitride Ceramic Under Tensile Stress at Elevated Temperatures

2005 ◽  
Author(s):  
Hiro Yoshida ◽  
M. Munawar Chaudhri ◽  
Takero Fukudome ◽  
Sazo Tsuruzono
Keyword(s):  
Silicon Nitride ◽  
Tensile Stress ◽  
Elevated Temperatures ◽  
Strength Degradation ◽  
Stress Effect ◽  
Predominant Role ◽  
Silicon Nitride Ceramic ◽  
Impact Fracture Behavior ◽  
Grade Silicon ◽  
Effects Of Temperature

A series of particle impact tests was carried out at elevated temperatures up to 1400°C and under tensile stresses up to 200 MPa using a gas turbine-grade silicon nitride (SN282-Kyocera Corporation). It was found that: 1) At room temperature, 100 MPa tensile stress brings 8% strength degradation. 2) Regarding the effect of the temperature without applying tensile stress, similar to the case of quasi-static loading, the fracture toughness seems to play a predominant role under the dynamic loading also. 3) At 1350°C under 100 MPa tensile stress, effect of the stress on the degradation increases by 15%. 4) The effects of temperature and tensile stress on the strength degradation seem to be additive for temperatures up to 1350°C. Above 1350°C, remarkable strength degradation appears.

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