Mechanical Design, Manufacturing and Engineering Forum
[ Home ] [ Search ] [ Engineering and Design Database ] [ Resume/Job Database ] [ Product and Services Directory ]
[
Engineering, Design and Drafting Store ] [ Engineering Forum ] [ DFM DFA Training and Trainers ] [ GD&T Training GD&T Trainers ] [ Advertise ]
[ POSTING POLICY / RULES ][ Archive#1 ] [ Archive #2 ] [ Archive #3] [ Calculators ] [ Tell A Friend ]
Forum Moderators: randykimball, Administrator

Vickers Hardness Testing Question
Post Reply   Forum
Posted by: RShortt

04/05/2005, 08:35:09

Author Profile Mail author Edit
Does anyone know what determines the force exerted on a surface when testing hardness of that surface using the Vickers Hardness Tester?
I have a ground, polished surface of approx 3.16mm diameter and I need to know which one of 1/3/5/10/20/30/50/100kg loads I am to apply and for other diameters, how do I know which load I am to apply?






Post Reply | Recommend | Alert View All   | Next |

Replies to this message


Re: Vickers Hardness Testing Smile
Re: Vickers Hardness Testing -- RShortt Post Reply Top of thread Forum
Posted by: Thorpy

04/06/2005, 14:38:05

Author Profile Mail author Edit
The Vickers hardness number (HV) is the ratio of the load applied to the indentor to the surface area of the indentation.
In theory, the load doesn't matter as long as the shape of the indentor (a square based pyramidal) is deep enough and isn't distorted.

To obtain the greatest accuacy the load should be as large as possible, as long as you don't over distort the surface. for soft materials (plastics, etc) use lower weight. For hard metals use upto the 50Kg. Any larger and there is a potential to fracture the diamond.

With HV, you can use any weight as long as you are happy with the resulting indentation and your ablity to measure it. Since you are new, you should do several trials at different weights (if metal say 20,30, 50 kg) so you can better understand the effect of weight on the indentation and your ablity to calculate the Surface area. Remember when doing actual measurements to leave at least ten indentations away before you remeasure. This is so that any stress imparted by the last measurement don't affect the next measurement

Regards

Thorpy







Post Reply | Recommend | Alert Where am I? Original Top of thread

Powered by Engineers Edge

© Copyright 2000 - 2018, by Engineers Edge, LLC All rights reserved.  Disclaimer