how does vickers machine work? what is tensile test?

Answer 1

Vickers indentation is used to determine the hardness or toughness of a material. It uses a pyramidal indenter and indents at a specified load. The hardness can be calculated from the projected area of the indent and the load. See the first reference for more detail.

A tensile test is when you pull apart on the ends of a sample. There's a lot of information you can get from it, but mainly people are interested in the modulus (stiffness), yield strength, and ultimate tensile strength. See the second reference for more detail.