[Ramzi Kassab]

Hi every body
Im working in acompany that work in oil well bits repair,
The cutting elemint is a Polycrystalline diamond cutters (PDC)  its a circular piece of diamond supported on tungsten carbide substrate , if the cutting edge cracked we rotate it under heat up to 1100° F to expose agood edge .
The problem here that under that temperature the glowing prevent us to see clearly and many times we redo that work.
  l have an idea to put asmall mark on the cutting diamond  or asubstrate ,what is the sutable material for this job?
Must not react with the diamond or substrate
And glow in adifference color at that temp. (Not red)
Thank you all.