Surface preparation of silicon carbide for improved adhesive bond strength in armour applications

Abstract

Surface treatments of silicon carbide have been investigated with the aim of improving the strength of the bond between the ceramic and an epoxy adhesive. Three surface conditions have been characterised; as-fired, air re-fired and KrF laser processed. A number of characterisation techniques have been used to determine the morphological and chemical changes that have occurred to the surface. Scanning electron microscopy of the re-fired and laser processed samples showed surfaces that appeared glassy, with the laser processed surface showing a different morphology. X-ray photoelectron spectroscopy indicated both treatments had oxidised the surface and the laser processed surface also had a greater concentration of hydroxyl groups. The wettability of both surfaces had improved and the laser processed surface was found to be highly hydrophilic. Mechanical testing of joints prepared with this technique showed them to have the highest strength in tension, with the locus of failure being cohesive. © 2013 The Authors

Surface treatment of alumina ceramic for improved adhesion to a glass fibre-reinforced polyester composite

“…However, values quite similar to our results have also been found by others [9], so these are as expected for commercial alumina tiles. The large deviation from the theoretical value(s) is usually explained by organic contamination, which may be present even in clean rooms and is difficult to remove completely [36].…”

“…oils and greases) from the surface, maximise the degree of molecular contact between the surface and the adhesive, and to ensure that the intrinsic adhesion forces across the interface are sufficient to achieve adequate bond strength [8]. Methods to prepare ceramic surfaces for adhesive bonding include grit-blasting [9][10][11], abrasion [12], plasma [13][14][15], laser ablation [9,16], sol-gel [10,11] and silane treatment [17][18][19]. In some of these studies, the main focus was on the evaluation of the effect of the adhesive bondline between ceramic tiles and a metal backing plate.…”

“…One exception is the work conducted by Harris et al [9,16]. They found that the adhesive bond strength to both alumina and silicon carbide could be improved when employing epoxy adhesives.…”

“…Harris et al also conducted ballistic testing on panels that were made from ceramic tiles backed by adhesively bonded sheets made from a ballistic fibre [21]. The testing suggested that improved ceramic/adhesive bond strength had an effect on the ballistic performance of the panels, e.g.…”

Surface engineering alumina armour ceramics with laser shock peening

“…al. [20]. They explored the bond strength as result of three surface conditions: as-fired; air re-fired and KrF laser surface processing.…”