What mechanical property indicates a material's ability to absorb energy before fracturing?

Toughness is the mechanical property that indicates a material's ability to absorb energy before fracturing. It reflects the material's capacity to withstand tensile and impact stress without breaking. This property is particularly important in applications where materials might be subjected to sudden impacts or dynamic loads, as it ensures that the material can deform and absorb energy instead of failing catastrophically.

In contrast, hardness measures a material's resistance to deformation and scratching, but it does not provide information about its energy absorption capabilities. Ductility refers to a material's ability to deform under tensile stress, which is vital for applications requiring stretching or shaping, but it, too, does not directly relate to energy absorption before fracture. Strength is a measure of the maximum load a material can withstand before failure but does not inherently imply energy absorption capabilities. Thus, toughness encompasses both strength and ductility, making it the crucial property for understanding a material's behavior under impact and its overall durability.