Which outcome typically occurs when applying stress to a polycrystalline material?

💡 Explanation

Intergranular crack nucleation accelerates because applied stress concentrates at grain boundaries. Increased stress induces micro-cracks through a mechanism of grain boundary decohesion. Therefore, crack nucleation accelerates in polycrystalline substances, leading to failure, rather than strengthening or predictable slip.

• Which instability increases within supersonic nozzle's boundary layer?
• Which outcome arises from a sustained *stimulated emission* within a fusion reactor plasma?
• Which outcome occurs when a refrigeration cycle's subcooling decreases significantly?
• Which heat-engine inefficiency arises because temperature remains constant during isobaric phase changes?
• Which consequence results when an inhibitor reduces reaction order?
• Which mechanism causes increased resistivity when lattice defects accumulate in a metal wire?