Estimation of material loss through electrical resistivity

[serbring]

Hi all,

I'm doing a little project about the wear of materials for tools for cutting machines.Yesterday, I was reading wikipedia page about electrical resistivity and I thought if it might be possible to evaluate the estimate the material loss of the tool through the measure of electrical resistivity. Might be possible or it is just "pure fantasy"? :)

 

[Student100]

Hi all,

I'm doing a little project about the wear of materials for tools for cutting machines.Yesterday, I was reading wikipedia page about electrical resistivity and I thought if it might be possible to evaluate the estimate the material loss of the tool through the measure of electrical resistivity. Might be possible or it is just "pure fantasy"? :)

Sounds reasonable without thinking about it too hard, the measurements would need to be taken at the same temperatures to ensure accurate results. It would also depend on how much material you lose between measurements and the sensitivity of your equipment. (Changes in resistance would need to be larger than the uncertainties in your measurement to draw anything accurate from it) It also wouldn't tell you where you lost the material, without some additional design if that mattered. Corrosion would be a concern, as well.

Can you provide additional context? What kind of tool? How much material are you losing from rough estimates? What kind of time frames for wear are you talking about?

 

[Nidum]

Not entirely fantasy but difficult to implement in most practical situations and very prone to giving false results .

Tool wear is most commonly monitored by some of these methods :

In cutting cycle by measurements of input power , vibration level , temperature rise or tool shank reaction force .

Out of cutting cycle by measurements of tool edge profile , workpiece surface finish or workpiece dimensional error .

 

[Nidum]

Measurement of vibration levels can be simple or very sophisticated .

A lot of work has been done on monitoring tool wear by analysing the broad spectrum 'sound' created by the cutting process .

 

[serbring]

Sounds reasonable without thinking about it too hard, the measurements would need to be taken at the same temperatures to ensure accurate results. It would also depend on how much material you lose between measurements and the sensitivity of your equipment. (Changes in resistance would need to be larger than the uncertainties in your measurement to draw anything accurate from it) It also wouldn't tell you where you lost the material, without some additional design if that mattered. Corrosion would be a concern, as well.

Can you provide additional context? What kind of tool? How much material are you losing from rough estimates? What kind of time frames for wear are you talking about?

You're on right, corrosion and temperature is something should be considered. When the tool should be changed, the material loss is about the 10% of the total tool weight and it usually occurs after a year.

Not entirely fantasy but difficult to implement in most practical situations and very prone to giving false results .

Tool wear is most commonly monitored by some of these methods :

In cutting cycle by measurements of input power , vibration level , temperature rise or tool shank reaction force .

Out of cutting cycle by measurements of tool edge profile , workpiece surface finish or workpiece dimensional error .

I was thinking of a solution for tillage tools but soil conditions (moisture, compaction) markedly affect the input power and vibrations are usually pretty high.