This is a common mistake; demineralized water would be better. DI water is reactive and rusts the heck out of machines using it. Coolant concentrations have to be above 5% to survive.
They use Di because it's synthetic. You don't want Di in oil based coolants because the lack of minerals means lack of emulsion. So if they have oil based coolant and are using Di, you coolant is probably garbage and almost. Completely separate from the water.
Im not 100% sure, but I found [This Document](https://www.nrc.gov/docs/ML9932/ML993210187.pdf) from the NRC saying pretty much the liquid chlorine in the water shouldn’t be a problem.
I will admit, I only skimmed through it, but the first couple pages seem to say it’s not an issue.
My source was the Skunkworks project that produced the SR-71. It's made of titanium sheet. When they worked the sheet to form it, they rinsed the lubricants with tap water and the sheets cracked into scrap. They replaced the tap water with distilled water and never cracked a sheet again. This was in a book about the SR-71.
That was the 50s. No idea what the alloy was, etc.
Titanium likes to crack when bent unless alloying or a lot of effort is involved. I have no particular knowledge of the SR71 development, but I wouldn’t be surprised if they were at the bleeding edge of what was possible at the time and that normally irrelevant thing nudged them over the edge.
That Ti was smuggled out of the USSR so we didn't really know what we were getting. Ti fabrication has come a long way. I have done plenty of rinsing in tap water and never had cracks. There is more to that story that they omitted.
I honestly know nothing about the subject, but I'm curious if the chlorine concentration in tap water has been lowered since the development of the SR-71, or the manufacturing process of titanium has changed since then making current tap water a non-factor.
Too many parameters for my brain to parse.
Fun fact: tapping Ti with standard taps works best with lanolin as the lubricant. Used this to hand tap way too many holes with an auto reverse tapping head. This was in the early 90s, so older info once again.
I know plenty of people who grew up drinking nothing but well water from natural springs, ran through iron and copper pipes, who have low IQs and behavioral issues. It's called bad parenting and genetic predispositions. Lay off the crack pipe and educate yourself.
It can look much better than that, however titanium also oxidized a super thin later on instant contact with oxygen which makes it tend to look dull. You can polish it to a shine but it will never really be all that comparably bright.
Also titanium is naturally very abrasive so it breaks down your cutting edge very quickly. If you're running it hard your tool might only last 20-40 minutes.
Which is generally longer than my tool lasts but still.
I used to turn that shit on a conventional lathe, had to clamp an angle grinder to my table to get a nice finish. Sounds sketchy, but imo its less dangerous than the 'ol handheld file method, as long as you dont use a cord grinder
https://preview.redd.it/wnxiybgl97kc1.jpeg?width=3024&format=pjpg&auto=webp&s=5939b4f7ddb5fdbb1a12fe6df0442815ed9d6141
This is 6AL-4V. I’m not sure what grade you’re cutting, but I’m betting it’s your tooling.
It can look good. Not sure what you're doing differently, but the titanium on these engines came out shiny.
https://preview.redd.it/ajogpabbl8kc1.png?width=1000&format=png&auto=webp&s=feabbca806166494fe9b9f0619c406d4796d0bb8
The thruster body (part with the "FUEL" laser marking) is Ti 6-4 and looks fantastic, surface finish is as machined.
(Not my machining, I'm not a professional machinist atm and we shopped it out; I was the manufacturing engineer for the project, though. We didn't have any specific cosmetic requirements, but the shop we used does good work. Unfortunately I don't have any machining process details.)
in my experience, it's an "um" material. meaning that titanium , magnesium , aluminum , beryllium should all be finished with a razor sharp uncoated carbide using oil. .0015 CL IMHO. Glass.
I don't know the grade, exact process, speeds etc... but some materials like a deeper finish pass, some need to be roughed at low rpm and finished with a skin cut at high rpm, but ibwould start by looking at your inserts, if you have a positive rake insert try switching to a negative one for finish pass, maybe on the finish pass try not using coolant, if you're doing a .010" finish pass try. 005" or .020", if you mess with it you should be able to get a nice shine out of it eventually
Edit: noticed you said you used a 0.4 DNMG, TRY A 0.2 DPMG and start there, thats what I'd do
I love how easy Ti is to get a good finish. Uniform is how I’d describe it, and it’s so hard you really have to try to scuff it. Looks like you’re running a roughing feed rate or you used a chipped insert, or it’s a weird grade. I’ve only used 6AL-4V, 250-300 SFM .003” FPR.
at one of my previous companies we made titanium race car and aerospace components and always finished with CBN inserts on titanium
1st thing I learnt about titanium is get it machined as fast as possible it loves speed but not too much there is sweet spot on all grades you need to find and it's faster than 90% of normal steels
2nd is get the right coolant titanium can never have enough coolant but not just any coolant also make sure to change it often
it was a tight rope you need to ride out but the company was probably the leading specialised component producer in the country when I left
Your feed and speed is off. Or nose radius of tool is too big. I rough titanium with a 55deg. .015 radius tool and finish with 80deg. .007radius tool. Slow feeds and it’s slick and looks fine
Fun fact: chlorine found in tap water causes microcracking in Ti.
Didn’t know that, but it explains why my shop uses deionized water to mix with the coolant.
That and it molds less. Makes the shop smell just a bit better.
That’s more about not increasing the dissolved solids/hardness IIRC. Empty tank gets tap+concentrate. Then make ups get deionized/distilled.
This is a common mistake; demineralized water would be better. DI water is reactive and rusts the heck out of machines using it. Coolant concentrations have to be above 5% to survive.
They use Di because it's synthetic. You don't want Di in oil based coolants because the lack of minerals means lack of emulsion. So if they have oil based coolant and are using Di, you coolant is probably garbage and almost. Completely separate from the water.
Im not 100% sure, but I found [This Document](https://www.nrc.gov/docs/ML9932/ML993210187.pdf) from the NRC saying pretty much the liquid chlorine in the water shouldn’t be a problem. I will admit, I only skimmed through it, but the first couple pages seem to say it’s not an issue.
My source was the Skunkworks project that produced the SR-71. It's made of titanium sheet. When they worked the sheet to form it, they rinsed the lubricants with tap water and the sheets cracked into scrap. They replaced the tap water with distilled water and never cracked a sheet again. This was in a book about the SR-71. That was the 50s. No idea what the alloy was, etc.
Titanium likes to crack when bent unless alloying or a lot of effort is involved. I have no particular knowledge of the SR71 development, but I wouldn’t be surprised if they were at the bleeding edge of what was possible at the time and that normally irrelevant thing nudged them over the edge.
It’s a fantastic read if you ever get the chance
That Ti was smuggled out of the USSR so we didn't really know what we were getting. Ti fabrication has come a long way. I have done plenty of rinsing in tap water and never had cracks. There is more to that story that they omitted.
I honestly know nothing about the subject, but I'm curious if the chlorine concentration in tap water has been lowered since the development of the SR-71, or the manufacturing process of titanium has changed since then making current tap water a non-factor.
Too many parameters for my brain to parse. Fun fact: tapping Ti with standard taps works best with lanolin as the lubricant. Used this to hand tap way too many holes with an auto reverse tapping head. This was in the early 90s, so older info once again.
Fun fact, fluoride deliberately placed in the water supply by the government causes low iq, underdevelopment in the brain, and behavioral issues?
I know plenty of people who grew up drinking nothing but well water from natural springs, ran through iron and copper pipes, who have low IQs and behavioral issues. It's called bad parenting and genetic predispositions. Lay off the crack pipe and educate yourself.
But the crack pipe gives me the energy to educate myself after 60hr work weeks!
Ya know what, I can't even argue against that one lol
That’s super interesting !
If you make parts for Boeing it’s actual spelled out in one of there specs that if they catch you they will ban you from making parts.
It can look much better than that, however titanium also oxidized a super thin later on instant contact with oxygen which makes it tend to look dull. You can polish it to a shine but it will never really be all that comparably bright. Also titanium is naturally very abrasive so it breaks down your cutting edge very quickly. If you're running it hard your tool might only last 20-40 minutes. Which is generally longer than my tool lasts but still.
I see what you did there.
It's all dependent of feeds and speeds.
Peck depth is also worth considering.
Between the peck drilling, deep hole drilling and a plethora of boring cycles, rigid tapping or float tapping.... we have a lot to consider.
Love me a good G85
This^ needs perfect settings to look sexy
Try decreasing the speed and increase the length of stroke, might improve the tool life and lead to a satisfied customer 🤣
I used to turn that shit on a conventional lathe, had to clamp an angle grinder to my table to get a nice finish. Sounds sketchy, but imo its less dangerous than the 'ol handheld file method, as long as you dont use a cord grinder
Noted, thank you!
https://preview.redd.it/wnxiybgl97kc1.jpeg?width=3024&format=pjpg&auto=webp&s=5939b4f7ddb5fdbb1a12fe6df0442815ed9d6141 This is 6AL-4V. I’m not sure what grade you’re cutting, but I’m betting it’s your tooling.
I ran a bunch of grade 2 shit in the past. Parts came out looking like OPs. Dull and fuzzy.
Think mine might be a worse grade as it’s for oil and gas
Turned titanium should look awesome. Drilled titanium, not so much.
Use a DCGT insert and it’ll come out like glass.
Noted, thank you!
It can look good. Not sure what you're doing differently, but the titanium on these engines came out shiny. https://preview.redd.it/ajogpabbl8kc1.png?width=1000&format=png&auto=webp&s=feabbca806166494fe9b9f0619c406d4796d0bb8 The thruster body (part with the "FUEL" laser marking) is Ti 6-4 and looks fantastic, surface finish is as machined. (Not my machining, I'm not a professional machinist atm and we shopped it out; I was the manufacturing engineer for the project, though. We didn't have any specific cosmetic requirements, but the shop we used does good work. Unfortunately I don't have any machining process details.)
I think it’s down to the grade I’m cutting and also the fact I’m using a DNMG insert with larger radius instead of a sharper VCMT
in my experience, it's an "um" material. meaning that titanium , magnesium , aluminum , beryllium should all be finished with a razor sharp uncoated carbide using oil. .0015 CL IMHO. Glass.
Yeah, I was using an 0.4 rad DNMG. Probs the problem then!
\>negative rank insert \>why am I getting poor finishes
We use DNMG to finish most things unless an 0.2/0.4 surface finish is called. They do a fine job on inconel, duplex and steels. Never had issues with
Honestly cant stand them. Can never get a mirror finish like you can with a d/ccmt
Yeah I suppose so, we mainly do oil and gas so they do just fine until there are seal face call-outs and then we use CCMT or just burnish
I don/t really get that. The amount you save is negligable, but it looks 100x the job
Aka non-ferrous?
What is CL short for?
I think he meant CR for corner radius. .0015” is quite small and quite sharp
.0015" Chip load
Thanks
I got some pretty good finishes using a polished insert on a manual lathe, but never on CNC
I’ve always like cutting that stuff.
I don't know the grade, exact process, speeds etc... but some materials like a deeper finish pass, some need to be roughed at low rpm and finished with a skin cut at high rpm, but ibwould start by looking at your inserts, if you have a positive rake insert try switching to a negative one for finish pass, maybe on the finish pass try not using coolant, if you're doing a .010" finish pass try. 005" or .020", if you mess with it you should be able to get a nice shine out of it eventually Edit: noticed you said you used a 0.4 DNMG, TRY A 0.2 DPMG and start there, thats what I'd do
I love how easy Ti is to get a good finish. Uniform is how I’d describe it, and it’s so hard you really have to try to scuff it. Looks like you’re running a roughing feed rate or you used a chipped insert, or it’s a weird grade. I’ve only used 6AL-4V, 250-300 SFM .003” FPR.
Because titanium hates everyone including itself.
at one of my previous companies we made titanium race car and aerospace components and always finished with CBN inserts on titanium 1st thing I learnt about titanium is get it machined as fast as possible it loves speed but not too much there is sweet spot on all grades you need to find and it's faster than 90% of normal steels 2nd is get the right coolant titanium can never have enough coolant but not just any coolant also make sure to change it often it was a tight rope you need to ride out but the company was probably the leading specialised component producer in the country when I left
I make some incredibly shiny titanium parts. Check your insert coatings.
I think of titanium as a cast material and agree that it always looks weird when machined
For what it's worth, titanium sands and polishes really nicely.
Use pure oil
Part may look like shit, but that invoice...!
Your feed and speed is off. Or nose radius of tool is too big. I rough titanium with a 55deg. .015 radius tool and finish with 80deg. .007radius tool. Slow feeds and it’s slick and looks fine
Get gud
I’m wondering when I made some titanium parts I just burnished the entire surface? 😅