Chemical and mechanical analysis of tribofilms
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That is an intense paper. I wasn't able to read through all of it. The most important part is in the last paragraph (of course
) and is this:
Quote:
The implications of this study are that ZDDP does not
act fully as an antiwear agent in FF oil (in the form of Zn
phosphate), and possibly only facilitates the initialisation
of film formation. Once the onset of film formation occurs,
a ZnS and Ca phosphate film grow based on availability of
cations present and in agreement with the chemical
hardness predictions.
Might explain why SM oils don't have higher wear rates.
Also:
Quote:
Another interesting observation was that no B was
detected in the film.
Leaves a big question mark as to why it reduces wear so much synergistically with ZDDP.?
Quote:
The implications of this study are that ZDDP does not
act fully as an antiwear agent in FF oil (in the form of Zn
phosphate), and possibly only facilitates the initialisation
of film formation. Once the onset of film formation occurs,
a ZnS and Ca phosphate film grow based on availability of
cations present and in agreement with the chemical
hardness predictions.
Might explain why SM oils don't have higher wear rates.
Also:
Quote:
Another interesting observation was that no B was
detected in the film.
Leaves a big question mark as to why it reduces wear so much synergistically with ZDDP.?
It's easiest to read through when printed, at least for me it was. It's really cool that the tests were done on a fully formulated oil (Mobil 1 5W-30) rather than just one or a few additives in oil. I was surprised that no boron was detected in the film. So what is the additive's purpose then? I don't know what kind of boron molecule is in Mobil 1 5W-30; maybe it's unlike the kind that you and I are thinking of that can act synergistically with ZDDP.
The B is thought to be a donor or carrier for other elements that are used in the film.
This is one of the fewer studies that used fully formulated oil. It just shows that you have to read all the studies and put them together somehow. The oil with only ZDDP at a high concentration had much more wear, again, showing that having more ZDDP is not necessarily better. It is the whole formula of additives that must be balanced. This also goes along with my thinking that we should not mix oils to make our our concoctions.
aehaas
This is one of the fewer studies that used fully formulated oil. It just shows that you have to read all the studies and put them together somehow. The oil with only ZDDP at a high concentration had much more wear, again, showing that having more ZDDP is not necessarily better. It is the whole formula of additives that must be balanced. This also goes along with my thinking that we should not mix oils to make our our concoctions.
aehaas
I quit mixing oils, unless it's the same manufacturer, same product line, and adjacent viscosities. I guess I could still foul up doing it this way.
Originally Posted By: AEHaas
The B is thought to be a donor or carrier for other elements that are used in the film.
aehaas
Could be. Do you know what molecule the boron is attached to in M1?
The B is thought to be a donor or carrier for other elements that are used in the film.
aehaas
Could be. Do you know what molecule the boron is attached to in M1?
From the article:
One of the most surprising finds was the lack of B within
the antiwear pads. B is not incorporated into the film, as
seen in exclusive studies involving ZDDP+B. This leads
to many questions:
(i) what happens if all the B containing components
are removed
(ii) does the molecule in which B is incorporated,
plays a more significant role than B itself?
A more comprehensive study is needed to rationalise
these findings.
aehaas
One of the most surprising finds was the lack of B within
the antiwear pads. B is not incorporated into the film, as
seen in exclusive studies involving ZDDP+B. This leads
to many questions:
(i) what happens if all the B containing components
are removed
(ii) does the molecule in which B is incorporated,
plays a more significant role than B itself?
A more comprehensive study is needed to rationalise
these findings.
aehaas
If ICP Spectroscopy was used in an effort to measure additive depletion and the Borate-EP contained in the oil had settled out, which it will, and this precipitate is not part of the sample then you could not get an accurate picture of what is going on.
The topic of oil analysis is a very complicated one. I’m new here but have been reading through some old posts on this forum. The subject of taking a sample is also of interest. I’m no expert but I have experimented with engines a bit as you may have guessed if you read my posts on a 510 station wagon with a lot of miles on it doing everything wrong as far as the common knowledge I read here about thin oil being better. With the complicated formulations of new engine oil designed to meet legislative needs first and then propped up to do its real job the issue of analysis and sampling are becoming more important. The oil industry now has some self education to do and the services of tribologists are more important than ever. There is no long track record for new formulations and I fear that additives that were though to be the answer to a particular problem may be proven to be less useful than we thought. Some of these new formulations appear to suffer from fall out and to get a sample I’m having difficulty getting hold of that fallout. On one of our dyno runs we took a series of samples and could not find the Boron. After pulling the pan we found in on the bottom in the form of sludge and this is a brand new engine. The engine is a mule that we are using to work through the aerodynamics in the crankcase, that’s how we found the sludge. So we are trying to figure out how important the sampling process is and how to best take a sample. Don’t laugh. We must be stupid because we are finding different sampling techniques are producing different results. We are also finding that a product recommended to us is driving some of these components back into solution, Auto-Rx. If this forum is about a dialog and sharing of ideas I would like to read your comments. I would also like to thank someone named Terry for a whole string of posts over the years but it appears that he has disappeared, this at a time when someone like him would be more useful than ever. His thoughts appear to be clear and to the point. That’s why I asked the question about this form being a dialog among us as members. G-Man has already written that my questions about Castrol hit on a “sensitive subject”. To cut through all the stuff is anyone even considering what affect the sampling technique has and has anyone noticed any additive fall out?
1stTruck, there's a date of submission listed on the paper above, so that's likely the best way to judge when the oil was bought. It's probably regular M1 5W-30. All motor oils have additives that compete for bonding to the engine's metals so this is not unique to the oil in this test.
BarkerMan, some posters here have noticed that the boron atom, as measured by UOAs, does show it is partly "going off the radar". I've never seen it all disapear but have seen significant percentage decreases. Where it goes or why it goes off the radar is uncertain to me. Possibilities I see are:
1. It's very volatile and some of it evaporates out of the oil at a much higher rate than the rest of the oil volatizes
2. It gets filtered out after it bonds to something else which makes the molecule it's part of big enough
3. It falls out of solution
This paper indicates it's not likely not bonding to metal surfaces so we can likely rule that out as a possibility. Plus the concentration decreases are high enough that the metal surfaces couldn't accept that much buildup indefinately without issues arising.
What oil or oils did you use that allowed the buildup in the oil pan? And did you have the buildup tested chemically or at least feel it to check its consistency?
BTW, yes I think it's certain that sampling technique affects UOA results.
BarkerMan, some posters here have noticed that the boron atom, as measured by UOAs, does show it is partly "going off the radar". I've never seen it all disapear but have seen significant percentage decreases. Where it goes or why it goes off the radar is uncertain to me. Possibilities I see are:
1. It's very volatile and some of it evaporates out of the oil at a much higher rate than the rest of the oil volatizes
2. It gets filtered out after it bonds to something else which makes the molecule it's part of big enough
3. It falls out of solution
This paper indicates it's not likely not bonding to metal surfaces so we can likely rule that out as a possibility. Plus the concentration decreases are high enough that the metal surfaces couldn't accept that much buildup indefinately without issues arising.
What oil or oils did you use that allowed the buildup in the oil pan? And did you have the buildup tested chemically or at least feel it to check its consistency?
BTW, yes I think it's certain that sampling technique affects UOA results.
We had the Boron dropout with an oil called Lubro Moly and found it in some light sludge in the pan. I think it was a 5w-40 but I just can't remember. I think that sometimes if falls out of solution and then gets reabsorbed back into solution so that's what caused me to ask about sampling methods. We found higher Boron readings from samples taken from circulating hot oil then from non-circulating hot oil and it was repeatable. So I was just asking. It appears that some posters gain a lot of information from very few samples but I have never been smart enough to do that. For me it takes more work to get answers.
Interesting. Not too long ago (we can check dates on UOAs if needed), Lubromoly went from having no boron to quite a bit, so when did you use this oil? I used this oil in my VW 1.8T but didn't get UOAs so don't know which formulation I used.
In August of this year.
I swear there was an ealier UOA or VOA than the following one from October 2007, but couldn't find it. This UOA shows the high boron content in Lubromoly 5W-40.
http://www.bobistheoilguy.com/forums/ubb...rue#Post1006721
The boron or whatever substance you found in the oil pan is disconcerting. If this oil did it, what other oils would too? If this oil did it in your engine, what other engines did it and will it do it in too? This raises many more questions than just those. Hmmm....
http://www.bobistheoilguy.com/forums/ubb...rue#Post1006721
The boron or whatever substance you found in the oil pan is disconcerting. If this oil did it, what other oils would too? If this oil did it in your engine, what other engines did it and will it do it in too? This raises many more questions than just those. Hmmm....
It may be very common. There may be more to oil analysis than grabbing a sample and putting it in the mail.
IMHO Boron is NOT a reactive chemcial and does not lay down a film as ZDDP will I think it is more of a FM polar ester that is more friction reduction through polar activitly thus will not show up in a AW film
bruce
bruce
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Do you think the increased FM is what causes the reported synergy between the ZDDP and boron?
MolaKule
Staff member
"The boron or whatever substance you found in the oil pan is disconcerting. If this oil did it, what other oils would too? If this oil did it in your engine, what other engines did it and will it do it in too? This raises many more questions than just those. Hmmm...."
No one has established that the boron is contained in the sludge found in the pan, nor has it been established that there is boron dropout.
I seriously doubt the above since most Borons are Boron esters with the boron fully dissolved in the ester. Like Bruce said, both are polar and polar compounds stay in solution.
No one has established that the boron is contained in the sludge found in the pan, nor has it been established that there is boron dropout.
I seriously doubt the above since most Borons are Boron esters with the boron fully dissolved in the ester. Like Bruce said, both are polar and polar compounds stay in solution.
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