Hard turning with a ceramic insert

This is a short example of hard turning in our NLX-2500SY700. The material is available a "Thompson shaft" and is a carbon steel that has a case hardened outer layer about .05" thick. It comes pre ground to standard sizes and is widley used in industry. The purpose of the ceramic insert in this case is to remove the hardened outer layer, so that standard carbide cutting tools can be used on the soft inner layer after. This part was at the end of a run, my carbide inserts were starting to wear, and that is the reason for the sparks. The material, speeds and feeds involved with proper use of ceramic tools regularly generates a chip that looks like a glowing ribbon, and provides some interesting visual effect.

[@soundspark]

Case hardened means that once you turn away the hard material you have a soft core.

[@tenacious8717]

Awesome 👍

[@brettaustin8900]

Thanks pal, congrats on the job!

[@crazycooterMN]

The threader got me 3 years later 🤣🤣🤣

[@garylarson6386]

hard turning requires a rigid machine with no slop because of the light cuts, I hate the stringy chips

[@robinbiskupic2639]

try machining hdpe. Unlike metal the chips are stretchy which surprisingly makes things worse

[@soundspark]

​@@robinbiskupic2639UHMW says hello.

[@trevor6512]

could you get high production out of a ceramic insert like 30 sec ops

[@abimhhgrrcunzolebh1688]

No they don't last long, chip very easy

[@Samy-hh1wn]

so why not use coolant? what material is this and why does it make a burning shaving?

[@vxer1000]

Can't use coolant. Thermal shock will destroy the insert.

[@MP4Archive]

Ceramic inserts also utilize heat to encourage plastic deformation, or chip, to occur at lower tool pressures than what a carbide insert would require. Less heat = more cutting force required to form a chip

[@literoadie3502]

Would this benefit from coolant? I have heard CBN tools suffer chemical attack from water based coolants. Is this so with ceramic too?

[@Tinkle1]

Using coolant on ceramics will actually shock and break them, from what I've seen

[@muradzulfiqarkhanzada4395]

This is essence of hard turning the basic theory behind it, when the cutting tool penetrates the workpiece the generated heat in the cutting zone also travels longitudinally and preheat the upcoming material for cut. If you use coolant the heat could not travel and somehow trap or dissipate in the chip tool workpiece, interface zone.

[@tristinknee5650]

The idea behind hard turning is to plasticize the material immediately in front of the tool by building up enough heat to anneal the material immediately in front of hte insert, so coolant is not a good idea.

[@curtis2323]

Coolant will cause thermal shock in the ceramic and it will shatter

[@KGSNANI]

Using inserts pl

[@sicstar]

forbidden lametta :|

[@sumerrana6805]

maseen katayi aag moot rhi h

[@TheAlexLegolas]

Stainless pain in the ass