Good question. Of course, this time should be minimized as possible that also depends on device characteristics. Any case, for comparative analysis of different metals and alloys the fixed duration of tests is preferable.

Nanoindentation is recommended in order to set a low indentation load (< 10 mN)) and a high load rate (i.e. if max load is 10 mN use at least loading and unloading rate 20 mN/min) and keep as much as possible the material within its elastic behaiovur limit preventing creep. With nanoindentation you can also have an estimation of the creep by setting increasing dwell time starting from 0 and looking at the trend of the indentation depth. in the . However, consider that these conditions increases the noise and surface topography effects so that you need a very smooth surface to obtain representative results.

Thank you Serge V. Shil'ko for the reply. Would you like to elaborate please by some examples. That would be really nice

Thank you very much Simone Vezzu for the answer. That is really a good explanation. I have got a query. can you please explain the same in the context of Vickers micronidentation?

Regards

Subha Sanket Panda

Hi, more challenging to transfer this concept in Vickers microhardness test. This is because you have not the load-displacement recording as well a range of normal load much higher. You can try to go with low load (1g) and no dwell time but you are going to risk that your indent mark is very low and related measuring error very high. You need to find the thresold load at which creep begin and work just below this thresold to have the best results you can achive. However I recommend you nanoindentation. Best regards, Simone

Yes, the nanoindentation test is not equivalent to Vickers microhardness one (in mechanical sense) because presumes relatively large deformable volume of material. To solve the problem you may try estimate creep parameters using theoretical models of indentation.

Thank you very much Serge V. Shil'ko for the answer.