Ideal cutting edge wear (800x, nomarski)
At 800 x with use of Interference you can see cutting edge wear; on the photo this is visible by the dark line just behind the cutting edge.
Cutting edge wear is normal wear, caused by normal use.
Stress in Diamond (150x, polarised)
On this photo you can see stress in the diamond, particular in the radius part.
This stress is caused by the diamond grinding process of the radius...
Cutting edge wear + damage due to electrostatic discharges (800x, nomarski)
By higher magnification and the use of interference you can see cutting edge wear. A number of electrostatic discharges are found on the cutting edge, the largest discharge has created a kind of chip on the cutting edge.
The electrostatic discharges are caused by sparks between tool and workpiece during use.
Electrostatic discharge (150x, nomarski)
Heavy cutting edge wear, damage and chipping caused by electrostatic discharges.
Clearance wear (75x, polarised)
Shown is the front of the radius; severe wear on the clearance (or relief) of the tool. The clearance is damaged over a rather large part (~120µm deep).
Damage on the Clearance of diamond (150x, polarised)
By looking at the conical clearance of this tool with interference you can see damage on this part of the tool.
This damage is being caused by material from workpiece during cutting and is similar to crater wear on the rake side of the tool. During relap this damage, as a result the decreasing height, is found back in the cutting edge as tiny chips or irregularities.
Form wear (75x, polarised)+(300x, nomarski)
Severe form wear (application is aluminium optical mold production) as seen from the top and as seen from the front, where the radius cone is visible.
Crater wear (300x, nomarski)
Cutting edge wear, Crater wear, Chips, Form wear.
Crater wear is caused by the chip, hitting the rake face of the tool while being very hot (can be up to over 1200°C). However the wear is visibly big (leaving a kind of a crater) it is rather undeep: just ~3µm deep!!!.
Cutting edge wear + very small chip (1000x, nomarski)
At 1000x magnification with use of interference you can see cutting edge wear and some irregularities plus a very small chip. This wear is caused by normal use.
Cutting edge wear + damage due to electrostatic discharges + Chipping's (800x, nomarski)
At 800 x Nomarski you can see cutting edge wear + electrostatic discharges. Chipping has also heavy damaged the cutting edge.
Chipping (800x, nomarksi)
At 800 x Nomarski you can see al large number of very small chips.
These chips are probably caused by tension or stress in the diamond (due to forcing during grinding the radius).
Cutting edge wear + Crater wear + laping lines (75x, nomarski)
Cutting edge wear(double line behind the cutting edge) By using the interference you see crater wear . (also are there lines on the diamond caused by relapping of the tool).
Cutting edge wear and crater wear are caused by normal use of the tool.
Crater wear is being caused by material from the workpiece while cutting.
Clearance wear (75x nomarski)+(150x, polarised)
Cutting edge wear , light crater wear, light chipping and light damage on the cutting egde, severe form wear (deformation of the original radius shape).
Also shown is the front of the radius; severe wear and damage on the clearance (or relief) of the tool. The clearance is damaged over a rather large part (~150µm deep).
Cutting edge wear + light electrostatic discharges (75x, nomarski)+ (800x, nomarski)
Crater wear on centre and centre left side of the radius. Cutting edge wear (edge is slightly rounded off) on centre and centre left side of the radius.
Light damage on the edge and clearance of the tool due to electrostatic discharges.
Cracked diamond (150x, polarised)
Diamond is cracked due to some accident. The crack is making the weak orientation visible of the diamond.
Rings on lenses (75x, nomarski)+(75x, polarised)
Severe cuttig edge wear + form wear + crater wear + large chips, all causing rings on the surface of the lens. As visible, a kind of finger print is left behind...
Also note the severe form wear on the right side, used for roughing.
Rings on lenses (75x, nomarski)+(75x, polarised)
Severe cuttig edge wear + form wear + clearance wear, all causing rings on the surface of the lens. In this case the rings are formed by burning zones, as material is not being cut but rather forced off.
Application: single point turning on Gfeller lathe.