Re: On the relationship between hardness and yield strength

Kelven Leo wrote: 
Then, who can tell what hardness mean? That is, what is the physical
meaning of hardness? Is hardness a index of materials against (plastic)
deformation?  Unlike the yield strength, the elastic modulus which are
the fundmental properties of materials, hardness is only the "surface"
property of materials. The question is how to relate hardness with
those fundmental properties?


"Hardness" is the result of an experiment....

There are many ways to measure "hardness" and it has long been known that there is not necessarily a relatinship between them.

Youngsters often demand that "Hardness" really be "SOMETHING".

Real reading in good books will often mitigate that illness.

Those who don't read will never be satisfied, confident that if they persist, they will eventually discover the "Truth".

Bye .......
.

Relevant Pages

  • Re: Hardness tester wanted
    ... at least one of the different hardness tests is designed around ... surely be proportional to the relative hardnesses of the materials. ... Wilson, it measures the depth of penetration, not the diameter. ... Measure the diameter of ball bearing. ...
    (rec.crafts.metalworking)
  • Re: Changing over to ceramic bearings.
    ... "Materials Science and Engineering." ... and I get the concepts of hardness and fracture toughness. ... modulus, the "height" of the line, the strength. ... Callister also says that yield and hardness are related in metals, but says nothing of the sort for ceramics. ...
    (rec.bicycles.tech)
  • Re: Changing over to ceramic bearings.
    ... "Materials Science and Engineering." ... and I get the concepts of hardness and fracture toughness. ... modulus, the "height" of the line, the strength. ... Callister also says that yield and hardness are related in metals, but says nothing of the sort for ceramics. ...
    (rec.bicycles.tech)
  • Re: Hardness tester wanted
    ... Enco has a new one for 800 bucks iirc. ... at least one of the different hardness tests is designed around ... So I have get impressions, one in the unknown material, and one in the ... surely be proportional to the relative hardnesses of the materials. ...
    (rec.crafts.metalworking)
  • How to calculate hardness
    ... When it comes to measuring the "hardness" of a material, most tests are distinctly low-tech and basically involve pressing a diamond tip into the surface and measuring the size of the dent produced. ... The results, obtained from first-principles calculations alone, agree well with experimental data and could help scientists make harder materials (Phys. ...
    (sci.physics)