Interfacial Sliding Friction in Silicon Carbide–Borosilicate Glass Composites: A Comparison of Pullout and Pushout Tests

Abstract

Interfacial sliding friction stress (q) was assessed using both pushout and pullout tests on Sic-borosilicate glass composite specimens. Single-filament composite specimens were fabricated by heating to 950°C in argon borosilicate glass rods with fine-diameter (250-pm) capillary in which SIC filaments were inserted. The composite specimens prepared in this manner showed only frictional bonding. The maximum frictional sliding loads for pushout and the initial frictional sliding loads in pullout were measured as functions of the embedded length of the filament in the glass rods. The nonlinear variations of the frictional loads were analyzed using shear-lag models that include corrections for the effects of Poisson expansion or contraction on the sliding friction stress. It is shown that under identical conditions of composite fabrication the two tests give nearly identical properties for the interfaces. Pushout tests on hotpressed bulk composite specimens, however, showed both chemical bonding and a higher sliding friction stress relative to the single-filament capillary specimens. The presence of compressive residual stress on the filaments was independently confirmed by evidence of stress-induced birefringence. [

Interfacial frictional stresses and fracture toughness of biomorphic graphite/copper interfaces

“…The sample indent was imaged using backscattered electrons in topography mode to observe the depressed channel and indent dimensions. Copper channels present in the earlywood red oak vessels exhibited the highest interfacial frictional stress of 4.64 ± 2.95 MPa, while those in the latewood red oak vessels had much lower values, 0.17 ± 0.07 MPa.Roughly 20% of all push-in tests were discarded due to asymmetrical indents that were the result of the general non-uniformity of these naturally derived features.Literature values for interfacial frictional stresses in ceramic fiber-reinforced composites, designed to promote sliding, range from 2-3 MPa for glass ceramic/SiC and glass/SiC composites to 50-80 MPa in Ti/SiC and SiC/SiC composites[26][27][28][29]. The values measured in the earlywood channels of BioG/Cu composites have comparable values to the glass/SiC and glass ceramic/SiC systems, known to have negligible bonding, while the interfacial frictional stresses in the latewood channels fall below the reported literature range.…”

Frictional heating in a unidirectional fibre-reinforced ceramic composite

“…technique to supplement other methods, such as fibre pushout [9][10][11] and pullout experiments [12][13][14], which are currently used to estimate the level inteffacial shear that exists in fibre-reinforced ceramics.…”