Which mechanism of heat transfer involves direct contact between materials?

The mechanism of heat transfer that involves direct contact between materials is conduction. In conduction, heat energy is transferred from one molecule to another through direct contact, primarily occurring in solids. When molecules in a material are heated, they vibrate and collide with neighboring molecules, transferring energy in this way. This process is critical in many industrial applications, especially in understanding how heat can affect the physical properties of materials and the overall safety in a process safety management context.

In contrast, convection involves the transfer of heat through the movement of fluids (liquids or gases) and does not require direct contact between materials, but rather relies on the circulation of the fluid to distribute heat. Radiation transfers heat through electromagnetic waves and does not require any medium, allowing heat to be transferred through a vacuum. Evaporation is a process that involves the change of a liquid into a gas, which can also absorb heat but is not a mechanism of heat transfer through direct contact.