Which of the following is not a physical change caused by heat treating a metal or alloy?

The correct choice of "planting" reflects a term that is not associated with the processes of heat treating metals or alloys. Heat treating encompasses several methods, such as hardening, annealing, and tempering, all of which involve altering the physical properties of a metal or alloy through the application of heat.

Hardening is a process that increases the hardness and strength of a metal, typically by heating it to a specific temperature and then rapidly cooling it. Annealing involves heating the metal to a high temperature and then slowly cooling it, which enhances ductility and reduces brittleness. Tempering follows hardening; it involves heating the metal at a lower temperature to relieve stress and improve toughness.

In contrast, "planting" does not relate to any established heat treatment processes in metallurgy. Instead, it may be confused with unrelated concepts or terminologies, making it the appropriate choice for the option that does not describe a physical change caused by heat treating a metal or alloy.