Dr Brian Gabbitas explains how the microstructure of a metal can affect its mechanical properties. Alloying titanium with aluminium and vanadium alters the crystalline microstructure, which results in a change in mechanical properties.
Point of interest
What types of crystal structure do metals show?
DR BRIAN GABBITAS
There is a very strong relationship between the microstructure of the metal and the mechanical properties. And the variables are alloy content – what are we mixing with the titanium? – and typically these would be aluminium and vanadium metal to make an alloy. Metals are crystalline, and if you observe a metal under an optical microscope, you would see that it’s made up of interconnecting grains, where each grain is a single crystal, and the average size of the collection of grains has a strong influence on the strength of the material. The microstructure is strongly related to the way that we process the material and to the way that we heat treat the material once we’ve processed it.
But that’s not the only factor. As well as the size of the grains, we can have different phases, and these would be areas of slightly different chemical composition from one area to another, and that distribution and morphology can also affect the properties of the material.