Ductility
Ductility can be quantified by the fracture strain formula_1, which is the engineering strain at which a test specimen fractures during a uniaxial tensile test. Another commonly used measure is the reduction of area at fracture formula_2. The ductility of steel varies depending on the alloying constituents. Increasing the levels of carbon decreases ductility. Many plastics and amorphous solids, such as Play-Doh, are also malleable.
The most ductile metal is platinum and the most malleable metal is gold.
Material criticality
Metals are among the most important materials to the industrialized world, everything from infrastructure to personal electronic devices heavily relies on metals for production. As a result, global supply is being increasingly monitored and examined. For example, a recent study analyzed the varying levels of risk to the copper metals around the world. Another study found that increasing metal scarcity could alter typical industrial behavior. It also noted that metals heavily concentrated in certain geographic areas, such as strontium in China or the platinum group in South Africa and Russia; pose greater risk for supply disruptions.