Hardness of materials (Metals, Plastics and Ceramics) (Theory and Practice)

Hardness is a mechanical property of materials. It is defined as the resistance of a material to deformation in indentation or scratching. There are many types of hardness tests which we can perform on materials. Each test has its own procedure and the shape of the indenters. Hence, hardness is generally given as hardness number. The more fundamental way of defining hardness is the ratio of force of indentation to the projected are of the indent produced. The indent or the indentation marks is imaged and the projected area measured after performing the test using a microscope. Hence, this value of hardness uses the plastic ( and localized fracture) behaviour of the material. Hardness in the basic method of measurement is given in the unit of MPa, which is the same as the unit of pressure. (Your comments and questions are welcome).
Vickers Hardness; Meyer Hardness; Scratch Hardness; Brinell Hardness; Nanoindentation; Microhardness; Materials Science and Engineering; Mechanical Engineering; Tribology

[clinthightowerclinthightow]

Well done on the video. Thank you for posting. I needed a refresher for a clear understanding of hardness and this helped.

[grahamovermyer]

Hi there! I just wanted to say this video is fantastic! One thing I found difficult about school vs working as an engineer is attaching real world concepts and examples to the theory. So just by showing the scratch tests and reiterating the main points of the lecture, you're really helped me solidify my understanding of the hardness material property. Thank you!!!

[randatatang]

Thanks so much. Hardness has been defined as resistance to plastic deformation. That's somehow similar to stiffness which is resistance to elastic deformation. My question is: is hardness analogous to stiffness, is it a rough equivalence of stiffness in the plastic region? I'm asking this in the hope that there's a way for me to make sense of hardness using the stress strain curve even though tensile test doesn't measure hardness. I keep wondering about that given that stiffness and hardness have the same unit and similar definitions. Would love to get your thoughts. Thanks

[kunalzshah]

So in principle, the higher the hardness, the less affected by abrasion the surface will be right?

[chhotelalroy]

Sir hindi me bhi btayiye dono ka mixup

[rameshbhivare]

Hello sir can you Make an video on
How to specify Hardness for particular parts
In machine tool Design most of time hard ness is used as wear resistant tool .
I didn't get how we Decide hardness value for materials.
If design spindles, Work head bodies, or casting material

[VISHAL_PAREKH]

sir mera selectioin mechanical ke baad ho nahi raha kyuki cocept koi samaj hi nahi aa rhe kya karu sir 8 saal ho gaye

[boodii-qveb]

Could please make a video providing industrial or engineering applications of hardness plz? Or reply on my comment here plz cuz i need it!