Ceramic boring on Inconel a must see

I thought I had flames coming from my carbide cutter on hard steel , but this is unbelievable.

Boring Inconel with a ceramic cutter

Steve.

Looks like you milling your tool holders.

I wonder how they predict the finished size

MichaelG.

Same way they do with any other CNC machines or do you have a specific query about that job?

.

Just thinking about the likely temperature rise ... or is it all just fireworks for show ?

MichaelG.

I imagine the theory is that the heat stays (mostly) in the the chips, so the workpiece doesn't heat up too much.

I definitely would not want one of those chips to land down the back of my shirt!

Martin.

Much like Stevie's insert cutter thread conclusion yesterday the idea is that the chips carry away the majority of the heat so what you are seeing is just a bunch of red hot chips swirling about inside the hole and not a red hot cutter or workpiece. The ceramic inserts can be run harder and faster so will plasticise and shear the chip more than carbide can.

The air that is blowing the chips away may also be acting as air blast cooling as well and it looks very much like they are roughing operations going by the finish on the side of the bore which clearly shows the helical descent of the tool as it spirals it's way down into the hole.

Finishing cuts may well be done with carbide and they may switch the liquid coolant on for that but it does soon get on the camera lense and spoil the viewing content.

This video popped up after watching Stevie's, still about machining inconel but this time with carbide and coolant, quite interesting to hear about the different machining approaches used for the harder material and he also explains a bit about the modern tendency to use as much as the side of the cutter rather than just the end as was done in the past. I've not watched any of his videos before but seems to know what he is talking about and gets it across well, obviously got some links with Kennametal.

**LINK**

Edited By JasonB on 09/05/2020 12:01:11

Edited By JasonB on 09/05/2020 12:02:13

Thanks, Jason

MichaelG.

For context ... Here is one of my favourite ‘Whitworth’ anecdotes:

MichaelG.

.

On a similar note. I remember seeing a film (and yes, I seem to remember it was a film) during my apprenticeship, showing "plasma turning" of HSS. A very fine, and precise, plasma torch went ahead of the cutting tool softening the HSS before the tool began to cut. At the end of the cut, the operator removed the work with his bare hand and it was barely warm. The point seemed to be, that the plasma torch was so precise, little heat got transferred to the work piece. I think I've got the basics there, but after 47 years who knows.

Impressive videos, I don't aspire to do anything like that in my shed!

I wonder what the workpieces are used for/ destined to be part of.

Rod

I know they use Inconel a lot in the oil industry. Worked at iCI Wilton in the 80's & they had a lot of pipework made from it. Never asked why.

Steve.

Aero industry for turbine engines use inconel 718 extensively. It's used mainly for its high strength and resistance to corrosion at elevated temperatures. Turbine blades and stators, engine to pylon mounts, engine attachment bolts etc are made from inconel. Got some engine bolts, but never dared to machine one...anyone wants to try 😝

That sort of thing proved fatal for Matrix Churchill and others in the 90's

Milled these turbine blades from 718 inconel ,not particularly hard material about
40 rockwell the main problem it work hardens if the tool is allowed to rub.
The 3 on the left were milled manually with a rather precarious setup of fixtures ,rotary
tables and indexers long before i had any cnc machines somewhere around 2001.
The cutter resting on the cast wheel on the right is a Dremel 12 tooth 9903
tungsten carbide carving bit , surprisingly these will mill this material quite well
after the discs are gashed out with an angle grinder.

John

We had one design at work that used 3/4" sch 5 Inconel pipe. This is 1.005" OD and 0.065" wall. Very close to 1" 16swg (0.064" ) tube we also used. Due to the not inconsiderable cost difference we had to make sure all the pipe fitters were aware of this Inconel being in the stores and to make sure they didn't take a piece for some of the non production parts they made (bracing weld assemblies for example). All the scrap had to be kept separate as well due to its value back to the company.

We could not cut it with hacksaws or bandsaws and had to use an abrasive cut off disk on it. We also found out that welding it took care as mistakes were very hard to repair.

Martin C

Unwanted emoji again

Edited By Martin Connelly on 09/05/2020 19:28:51

This guy does a lot of boring of Inconel and other exotics but unlike Stevie's video he gets a useful bit of material out of the hole with his homemade cutters, shows you how to make one in one of his videos.

There was a reason for not asking. I was always getting told off for asking too many questions. I am not sure but I think all the Inconel pipe was done with Tig.

Steve.

Good video. Some of those machines are Mahoosive. The steady reminded me of stargate SG1.

Steve.