How moving steel balls reveal the hidden grain structure of metals
Metals are not single, solid crystals but collections of tiny grains. This video uses a ball bearing model to demonstrate how heat treatment, specifically annealing, alters these grains to change a metal's fundamental physical properties.
The physical characteristics of a metal—including its strength, hardness, toughness, and ductility—are dictated by its internal grain size. This video explores how heating a metal can manipulate these grains. Using a model of self-organising steel balls, Steve Mould illustrates the process of annealing.
A key concept presented is ductility, which depends on how far dislocations can travel within the metal's structure. By changing the grain size through heat, the movement of these dislocations is altered, directly impacting the metal's plasticity and malleability.
Source: Self organising steel balls explain metal heat treatment
