Joining of sialon ceramics by a stainless steel interlayer

Diffusion phenomena in the α-Si3N4-solid solution and 304L stainless steel static interaction couple

“…Larger diffusivity of Si in the metal side is the resultant of two counter effects: it is favoured by the presence of Cr alloying in steel [14] while the dissolution of it is counteracted by the solution of nitrogen in steel [9]. Nitrogen liberated from dissociation of SiAlON from the ceramic side, in excess to dissolution to austenite, produces metal nitrides [10,11]. The presence of bSi 3 N 4 in XRD in NA is the outcome of reprecipitation process of Si (Si Fe ) after reaction with this nitrogen (N Fe ).…”

“…In both cases, the formation of the interface with graded hardness from steel on one end to the ceramic on the other side is expected to bring advantage [10,11]. Due to this hardness gradient, a gradation of properties exists from ceramic to steel through the reaction layer.…”

“…The study on chemical interactions between these ceramics and ferrous metals therefore provide most relevant information about the diffusion bonding between them as well as wear effects during tribological applications. Such studies on nature of chemical interactions, rate controlling steps, mechanisms vis-à-vis diffusion bonding and cutting performance against steel of b-Si 3 N 4 [1][2][3][4][5] and its one solid solution b-SiAlON [6][7][8][9][10][11] (b 0 , Si 3Àx Al x O x N 4Àx , x being up to 2.1) has already been studied quite extensively.…”

Fast bonding α-SiAlON ceramics by spark plasma sintering

“…2 In tool making and component preparation, ceramic joining is occasionally demanded and the related research has attracted extensive interests in the last years. The low self-diffusion coefficient of the covalent Si-N bond has led to the application of metallic [3][4][5][6][7] or non-metallic [8][9][10] interlayers to joint silicon nitride. The so-called diffusion bonding of silicon nitride in the literature actually also includes these kinds of interlayers [3][4][5] ature under pressure for rather long holding times even up to hours.…”

Preparation of sialon–transition metal silicide composites

“…The large size inhomogeneity could generate microcracks due to thermal expansion mismatch between the metal and ceramic phases. Furthermore, Si 3 N 4 is very reactive to many transition metals [9][10][11] directly to form metallic silicides and generate gas phases. These reactions usually take place before the densification of the composite systems, so fully dense composites are thus difficult to be achieved.…”