Frangibility
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A material is said to be frangible if through deformation it tends to break up into fragments, rather than deforming elastically and retaining its cohesion as a single object. Common crackers are examples of frangible materials, while fresh bread, which deforms plastically, is not frangible.
A plaque marking the frangible section of a London pavement, designed to be broken to release smoke in the case of an underground fire.
A sequence of photos showing a frangible bullet fracturing when subjected to high velocity strain waves
Spall
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Spall are fragments of a material that are broken off a larger solid body. It can be produced by a variety of mechanisms, including as a result of projectile impact, corrosion, weathering, cavitation, or excessive rolling pressure. Spalling and spallation both describe the process of surface failure in which spall is shed.
A chunk of armour knocked from HMS New Zealand's 'X' turret during the Battle of Jutland on display at the Torpedo Bay Navy Museum in Auckland. Caption reads, "The chunk of armour plating you see here was gouged out of X turret by a German shell."
Desquamation of dunite boulder
Granite dome exfoliation