ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Bending and contact strength of a carbon derived in-situ reinforced Si3N4-SiC micro/nanocompositehave been investigated. Four-point bending strength was measured using specimens with differenteffective volume and Weibull statistical analysis has been used for characterization of the strengthvalues in the form of characteristic strength and Weibull modulus. The characteristic strength valuesof the investigated composite were σ0 = 675 MPa and σ0 = 832 MPa with the Weibull modulus of6,4 and 8,6 for the specimens with effective volume 15,9 mm3 and 1,28 mm3 respectively. Contactstrength of the investigated material was carried out using sphere on sphere and roller on rollermethods and the obtained results are σ0S = 1997 MPa, σ0R = 1242 MPa, and mS = 17,1 mR = 6.Fracture origins in the specimens with effective volume of 15.9 mm3 tested in four-point bendingwere surface and volume located technological defects with dimensions from 10 μm to 180 μm,mainly in the form of clusters of pores and large SiC grains. Fracture mirror sizes were measuredand the mirror constant was calculated. Fracture origins in the specimens with effective volume of1.28 mm3 tested in four-point bending were surface (subsurface) defects with the same type as forthe specimens with a higher effective volume. The fracture during the contact strength test„roller/roller“ has been initiated under the surface of the specimens and during the contact strengthtest „sphere/sphere“ by creation and growth of the cone cracks to critical size
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/18/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.567-568.177.pdf
Permalink