Damage mechanisms in silicon nitride wire-rolling tools: Lab-scale experiments and correlation with finite element modeling

Characterization of a silicon nitride ceramic material for ceramic springs

“…The relatively large scatter in fatigue strength data obtained for helical springs is due to the intrinsic complexity of the machining and surface finishing and consequently, possible discrepancy in the surface quality of the individual samples. Although SEM ceramographic cross-sectional analysis and inspection of the ground surfaces of the springs did not reveal the presence of large surface defects or cracks (Figure 15), it has been shown in a previous study [27] that natural flaws in ceramic components (e.g., processing and machining-induced flaws) are extremely difficult to identify by means of microscopy. The presence of machining induced flaws may, however, explain the relatively large number of springs failing during the first 100 loading cycles in fatigue tests.…”

“…Nowadays, advanced ceramics are standard materials for components and tools that are exposed to severe mechanical, thermal and tribological loads [1,2,3,4,5,6,7,8,9,10]. The application of advanced ceramics is widely found in biomaterials [11,12,13,14,15,16], metal cutting [17,18,19,20,21,22,23,24], metalforming [25,26,27,28,29] and other manufacturing tools [30] and machine components such as valves, pistons, screws, gears and bearings. At high temperatures and in corrosive environments ceramics offer a viable alternative to metals.…”

Simulation of the laser-material interaction of ultrashort pulse laser processing of silicon nitride workpieces and the key factors in the ablation process

“…The E eph is the amount of energy that is ultimately used to heat the lattice at the laser penetration depth. Equation (20) provides the calculation regarding increasing the lattice temperature [36]:…”