When a material’s physical or chemical property is altered especially in industrial and metalworking processes, this is automatically referred to as heat treating or heat treatment. A very common application of this is metallurgical. Heat treatments are used in the manufacturing of different materials similar to glass.
Heat treating involves the usage of chilling or heating, typically to the extreme temperature to be able to attain the desired result like softening or hardening of a material. Techniques used in heat treatment are plentiful including case hardening, annealing, precipitation strengthening, quenching, normalizing and tempering. It’s smart to put stress that while such term is only applicable to processes where cooling and heating are done for a particular purpose of modifying properties intentionally, the cooling and heating normally take place incidentally throughout other manufacturing procedures just like in welding or hot forming.
Metallic materials consist of microstructure of small crystals also known as crystallites or grains. The nature of grains like composition or grain size is among the most efficient factors that determine the overall mechanical behavior of metal. Heat treatment is providing an effective way of manipulating metal properties by controlling the diffusion rate as well as cooling rate within microstructure. Heat treatment is mostly used for altering the mechanical properties of metallic alloy, manipulating properties similar to toughness, strength, hardness, elasticity and ductility, get additional info now!
There are two mechanisms that could possibly change the properties of alloy during the heat treatment and it’s the diffusion mechanism which makes the changes in alloy’s homogeneity and formation of martensite that causes the crystals to deform intrinsically.
Structure of crystal consists of atoms that are specifically arranged in a group known as lattice. In other elements, this order rearranges itself depending on the conditions it is on like pressure and temperature. This said rearrangement is known as polymorphism or allotropy and it can occur several times, at different temperatures for certain kind of metal. Now in the subject of alloys, this rearrangement can make the element not dissolve normally into a base metal to be soluble while allotropy reversal can make the element to be either completely or partially insoluble.
When it is in soluble state, diffusion process will make the dissolved atoms to spread while forming homogenous distribution within the base metal’s crystals. If ever the alloy is cooled to insoluble state, atoms of dissolved constituents might move out of the solution. Precipitation is what’s called to the diffusion that lead to nucleation in which all migrating atoms are regrouping together at grain boundaries. This will create 2 or several distinctive phases when it forms into microstructure, find out more by clicking here!