PTFE tape...

Peter Cole said:

dvt said:

Peter Cole wrote:

Quoted message said:

Quoted message said:

Quoted message said:

Find one that's steel-to-steel.

Quoted message said:

Quoted message said:

A slight modification of the search terms...

<http://scholar.google.com/scholar?hl=en&lr=&q=diffusion+bond+%22steel+to+steel%22&btnG=Search>

I looked at the first link returned. Or perhaps you prefer...

<http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TW2-3YWX3V2-3H&_coverDate=03%2F31%2F2000&_alid=521906506&_rdoc=1&_fmt=&_orig=search&_qd=1&_cdi=5550&_sort=d&view=c&_acct=C000014439&_version=1&_urlVersion=0&_userid=209810&md5=455395599933954c66bdb122b2ac330c>

From that paper:

"Crucible S7 tool steel was... prepared in a vacuum hot press using
bond conditions of 1100°C and 10, 5 and 20 MPa (Samples 1, 2 and 3)
for 20 min."

Quoted message said:

I can't read either -- the first is illegible, the second requires
membership.

Here's a link for the patent with more legible text:

<http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=3444608.PN.&OS=PN/3444608&RS=PN/3444608>

For the second, I included the pertinent text. It looks to me like steel
can be diffusion bonded. Welding and brazing are quite effective and
typically cheaper. Perhaps that's why we rarely hear about diffusion
bonded steel parts.

Quoted message said:

In any case, yes, you can bond steel to steel in a vacuum, even without
all the temperature and pressure, I knew that, but that isn't going to
happen in a bottom bracket bearing.

As I said before, I don't know if this type of bonding plays a role in
headsets and bottom brackets. jim beam seems to think it does, but as
usual, I don't know where he gets his information.

--
Dave
dvt at psu dot edu

Everyone confesses that exertion which brings out all the powers of body
and mind is the best thing for us; but most people do all they can to
get rid of it, and as a general rule nobody does much more than
circumstances drive them to do. -Harriet Beecher Stowe, abolitionist and
novelist (1811-1896)

dvt said:

Peter Cole said:

dvt said:

Peter Cole wrote:

Quoted message said:

Quoted message said:

> Find one that's steel-to-steel.

Quoted message said:

Quoted message said:

A slight modification of the search terms...

<http://scholar.google.com/scholar?hl=en&lr=&q=diffusion+bond+%22steel+to+steel%22&btnG=Search>

I looked at the first link returned. Or perhaps you prefer...

<http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TW2-3YWX3V2-3H&_coverDate=03%2F31%2F2000&_alid=521906506&_rdoc=1&_fmt=&_orig=search&_qd=1&_cdi=5550&_sort=d&view=c&_acct=C000014439&_version=1&_urlVersion=0&_userid=209810&md5=455395599933954c66bdb122b2ac330c>

From that paper:

"Crucible S7 tool steel was... prepared in a vacuum hot press using
bond conditions of 1100°C and 10, 5 and 20 MPa (Samples 1, 2 and 3)
for 20 min."

Quoted message said:

I can't read either -- the first is illegible, the second requires
membership.

Here's a link for the patent with more legible text:

<http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=3444608.PN.&OS=PN/3444608&RS=PN/3444608>

For the second, I included the pertinent text. It looks to me like steel
can be diffusion bonded. Welding and brazing are quite effective and
typically cheaper. Perhaps that's why we rarely hear about diffusion
bonded steel parts.

Quoted message said:

In any case, yes, you can bond steel to steel in a vacuum, even
without all the temperature and pressure, I knew that, but that isn't
going to happen in a bottom bracket bearing.

As I said before, I don't know if this type of bonding plays a role in
headsets and bottom brackets. jim beam seems to think it does, but as
usual, I don't know where he gets his information.

I still can't read either. All the cases I've see with steel-to-steel
involved vacuum or coatings or were forms of friction welding. Some
metals will readily cold/diffusion weld to themselves or each other, but
steel-to-steel seems to be a case that's different. I would think that
if "jb" (not "JB"😉 was a real metallurgist he would not only know that
but know why as well.

Peter Cole said:

I still can't read either. All the cases I've see with steel-to-steel
involved vacuum or coatings or were forms of friction welding. Some
metals will readily cold/diffusion weld to themselves or each other, but
steel-to-steel seems to be a case that's different. I would think that
if "jb" (not "JB"😉 was a real metallurgist he would not only know that
but know why as well.

Y'know, maybe this whole Jobst Brandt/"jim beam" thing is an elaborate
joke that Jobst is playing on rbt; they do have the same initials,
afterall. Maybe Jobst decided to create an alternate identity, one
completely opopsite in character; who would make absurd statements,
lie about sources, distort other's posts, make ridiculous claims of
expertise - and of course, attack the real JB at each and every
opportunity.

If so, denial would be equivalent to proof - and should it come from
the lower-caste "jb", not the first time it would have been so
employed.

Quoted message said:

the lower-caste "jb"

Uh-oh, now you've done it...

Peter Cole said:

dvt said:

Peter Cole said:

dvt wrote:
> <http://scholar.google.com/scholar?hl=en&lr=&q=diffusion+bond+%22steel+to+steel%22&btnG=Search>

Quoted message said:

Quoted message said:

Quoted message said:

> <http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TW2-3YWX3V2-3H&_coverDate=03%2F31%2F2000&_alid=521906506&_rdoc=1&_fmt=&_orig=search&_qd=1&_cdi=5550&_sort=d&view=c&_acct=C000014439&_version=1&_urlVersion=0&_userid=209810&md5=455395599933954c66bdb122b2ac330c>

Quoted message said:

Quoted message said:

Quoted message said:

I can't read either -- the first is illegible, the second requires
membership.

Quoted message said:

Quoted message said:

Here's a link for the patent with more legible text:

<http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=3444608.PN.&OS=PN/3444608&RS=PN/3444608>

Quoted message said:

I still can't read either.

I'm sorry that none of the links worked for you. You have the patent
number (3444608), and there are lots of sources to see patents online.
Maybe you can find one that works for you. Regarding the journal
article, I'll also give you the reference info [1]. If you're so
inclined, you can look it up.

Quoted message said:

Quoted message said:

Welding and brazing are quite effective
and typically cheaper. Perhaps that's why we rarely hear about
diffusion bonded steel parts.

Quoted message said:

All the cases I've see with steel-to-steel
involved vacuum or coatings or were forms of friction welding. Some
metals will readily cold/diffusion weld to themselves or each other, but
steel-to-steel seems to be a case that's different. I would think that
if "jb" (not "JB"😉 was a real metallurgist he would not only know that
but know why as well.

I've hypothesized one possible reason: steel to steel joints are easily
welded or brazed, and those processes are often cheaper than diffusion
bonding. From the reading I've done, diffusion bonding seems to be
applied mostly where those other methods don't work.

Sorry to get so far OT...

[1] Anton I. Lavrentyev and James T. Beals, "Ultrasonic measurement of
the diffusion bond strength," Ultrasonics, Volume 38, Issues 1-8 , March
2000, Pages 513-516

--
Dave
dvt at psu dot edu

Everyone confesses that exertion which brings out all the powers of body
and mind is the best thing for us; but most people do all they can to
get rid of it, and as a general rule nobody does much more than
circumstances drive them to do. -Harriet Beecher Stowe, abolitionist and
novelist (1811-1896)

Quoted message said:

Peter Cole said:

I still can't read either. All the cases I've see with steel-to-steel
involved vacuum or coatings or were forms of friction welding. Some
metals will readily cold/diffusion weld to themselves or each other, but
steel-to-steel seems to be a case that's different. I would think that
if "jb" (not "JB"😉 was a real metallurgist he would not only know that
but know why as well.

Y'know, maybe this whole Jobst Brandt/"jim beam" thing is an elaborate
joke that Jobst is playing on rbt; they do have the same initials,
afterall. Maybe Jobst decided to create an alternate identity, one
completely opopsite in character; who would make absurd statements,
lie about sources, distort other's posts, make ridiculous claims of
expertise - and of course, attack the real JB at each and every
opportunity.

If so, denial would be equivalent to proof - and should it come from
the lower-caste "jb", not the first time it would have been so
employed.

Dear "jtaylor",

I enjoy implausible conspiracy theories as well as the next
who-wrote-Shakespeare nut:

http://en.wikipedia.org/wiki/Delia_Bacon

And there's more than just the shared initials to raise our
suspicions--both Jobst Brandt and jim beam live in the San Francisco
bay area.

But I've spoken to them both, so I know that they're two different
people--alas--who disagree vehemently.

(Of course, my testimony is suspect. I could be nothing more than an
out-of-control class project in abnormal psychology being conducted
without the teacher's knowledge over at St. Therese by a clique of
giggling Catholic schoolgirls.)

Cheers,

"Carl Fogel"

dvt said:

Peter Cole said:

dvt said:

Peter Cole wrote:
> dvt wrote:
>> <http://scholar.google.com/scholar?hl=en&lr=&q=diffusion+bond+%22steel+to+steel%22&btnG=Search>

Quoted message said:

Quoted message said:

>> <http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TW2-3YWX3V2-3H&_coverDate=03%2F31%2F2000&_alid=521906506&_rdoc=1&_fmt=&_orig=search&_qd=1&_cdi=5550&_sort=d&view=c&_acct=C000014439&_version=1&_urlVersion=0&_userid=209810&md5=455395599933954c66bdb122b2ac330c>

Quoted message said:

Quoted message said:

> I can't read either -- the first is illegible, the second requires
> membership.

Quoted message said:

Quoted message said:

Here's a link for the patent with more legible text:

<http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=3444608.PN.&OS=PN/3444608&RS=PN/3444608>

Quoted message said:

I still can't read either.

I'm sorry that none of the links worked for you.

This is a known "jim beam" evasion - when confronted with documentary
evidence that directly contradicts him, he claims that there is
something wrong with the text and he cannot see it or open the link or
read the file, etcetera.

Quoted message said:

dvt said:

Peter Cole said:

dvt wrote:
> Peter Cole wrote:
>> dvt wrote:
>>> <http://scholar.google.com/scholar?hl=en&lr=&q=diffusion+bond+%22steel+to+steel%22&btnG=Search>

Quoted message said:

>>> <http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TW2-3YWX3V2-3H&_coverDate=03%2F31%2F2000&_alid=521906506&_rdoc=1&_fmt=&_orig=search&_qd=1&_cdi=5550&_sort=d&view=c&_acct=C000014439&_version=1&_urlVersion=0&_userid=209810&md5=455395599933954c66bdb122b2ac330c>

Quoted message said:

>> I can't read either -- the first is illegible, the second requires
>> membership.

Quoted message said:

> Here's a link for the patent with more legible text:
>
> <http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=3444608.PN.&OS=PN/3444608&RS=PN/3444608>

Quoted message said:

I still can't read either.

I'm sorry that none of the links worked for you.

This is a known "jim beam" evasion - when confronted with documentary
evidence that directly contradicts him, he claims that there is
something wrong with the text and he cannot see it or open the link or
read the file, etcetera.

Dear J,

Er, you can't tell the players without a scorecard. (Or at least
following the thread.)

I think that's Peter Cole saying that he can't read the file. (It does
happen.)

And Dave Van Tol is politely saying sorry. (What else can he say?)

Which one do you think is masquerading as Jim Beam? Or is Jobst
pretending to be all three?

🙂

Cheers,

Carl Fogel

dvt said:

Peter Cole said:

dvt said:

Peter Cole wrote:
> dvt wrote:
>> <http://scholar.google.com/scholar?hl=en&lr=&q=diffusion+bond+%22steel+to+steel%22&btnG=Search>

Quoted message said:

Quoted message said:

>> <http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TW2-3YWX3V2-3H&_coverDate=03%2F31%2F2000&_alid=521906506&_rdoc=1&_fmt=&_orig=search&_qd=1&_cdi=5550&_sort=d&view=c&_acct=C000014439&_version=1&_urlVersion=0&_userid=209810&md5=455395599933954c66bdb122b2ac330c>

Quoted message said:

Quoted message said:

> I can't read either -- the first is illegible, the second requires
> membership.

Quoted message said:

Quoted message said:

Here's a link for the patent with more legible text:

<http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=3444608.PN.&OS=PN/3444608&RS=PN/3444608>

Quoted message said:

I still can't read either.

I'm sorry that none of the links worked for you. You have the patent
number (3444608), and there are lots of sources to see patents online.
Maybe you can find one that works for you. Regarding the journal
article, I'll also give you the reference info [1]. If you're so
inclined, you can look it up.

Quoted message said:

Quoted message said:

Welding and brazing are quite effective
and typically cheaper. Perhaps that's why we rarely hear about
diffusion bonded steel parts.

Quoted message said:

All the cases I've see with steel-to-steel involved vacuum or coatings
or were forms of friction welding. Some metals will readily
cold/diffusion weld to themselves or each other, but steel-to-steel
seems to be a case that's different. I would think that if "jb" (not
"JB"😉 was a real metallurgist he would not only know that but know why
as well.

I've hypothesized one possible reason: steel to steel joints are easily
welded or brazed, and those processes are often cheaper than diffusion
bonding. From the reading I've done, diffusion bonding seems to be
applied mostly where those other methods don't work.

Sorry to get so far OT...

[1] Anton I. Lavrentyev and James T. Beals, "Ultrasonic measurement of
the diffusion bond strength," Ultrasonics, Volume 38, Issues 1-8 , March
2000, Pages 513-516

As I said, I know steel-to-steel can be done, but it's difficult,
requiring either vacuum and/or interlayers.

From:
http://www.welding-advisers.com/PRACTICAL_WELDING_LETTER-PracticalWeldingLetterNo10.html

"The process is most commonly used for titanium in the aerospace
industry and sometimes it is combined with Superplastic Forming (a
special hot forming procedure). Ceramics can be diffusion bonded to
themselves and to metals. Metals and alloys that exhibit very low
solubility for interstitials (such as aluminum-, iron-, nickel-, and
cobalt- base alloys) are not readily diffusion bondable. However
practically any metal combination can he joined by diffusion bonding
using suitable interlayers."

The problem is in getting the metals to contact each other through the
ever present surface layers of oxides/contaminants. Also, by its very
nature (diffusion), diffusion bonding takes significant time. Both of
these issues make it very difficult for me to believe it is the major
mechanism of fretting in steel ball bearings.

Quoted message said:

dvt said:

Peter Cole said:

dvt wrote:
> Peter Cole wrote:
>> dvt wrote:
>>> <http://scholar.google.com/scholar?hl=en&lr=&q=diffusion+bond+%22steel+to+steel%22&btnG=Search>
>>> <http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TW2-3YWX3V2-3H&_coverDate=03%2F31%2F2000&_alid=521906506&_rdoc=1&_fmt=&_orig=search&_qd=1&_cdi=5550&_sort=d&view=c&_acct=C000014439&_version=1&_urlVersion=0&_userid=209810&md5=455395599933954c66bdb122b2ac330c>
>> I can't read either -- the first is illegible, the second requires
>> membership.
> Here's a link for the patent with more legible text:
>
> <http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=3444608.PN.&OS=PN/3444608&RS=PN/3444608>
I still can't read either.

I'm sorry that none of the links worked for you.

This is a known "jim beam" evasion - when confronted with documentary
evidence that directly contradicts him, he claims that there is
something wrong with the text and he cannot see it or open the link or
read the file, etcetera.

Exsqueeze me?

The first one was a scan/pdf type dense and hard to read, when I got the
"better" link my browser plug-in wouldn't render at all.

The devil is in the details here, and it's tedious to wade through
things like technical papers and patent filings to tease them out. I
think that the principle of diffusion welding/bonding is well known. If
you can squeeze metals together so that they actually touch (beyond a
few high points), atoms will diffuse across the boundary, forming a
metallurgical link. Diffusion takes time, and is aided by temperature.
The usual problem is oxides/contaminants. Some metals work well in that
their oxides are brittle and open up, allowing the parent metals to make
contact through the cracks. Other oxides diffuse back into the parent or
otherwise can be persuaded to break down. In any case steel-to-steel
appears to be one of the tougher types to diffusion bond and not likely
to be a process in ball bearing fretting. The processes I've seen all
have involved vacuum or interlayer elements.

Perhaps if someone could find a reference for steel-to-steel that didn't
involve anything exotic I'd change my mind.

jim beam said:

Peter Cole said:

dvt said:

Peter Cole wrote:
> dvt wrote:
>> [email hidden] wrote:
>>> http://www.read-wca.com/pwm.cfm
>>
>>> From what this article surmises, one
>>> can imagine that two optically smooth pieces of steel would in time
>>> become welded if resting on one another. That does not occur without
>>> motion between the two.
>>
>> I think they *would* become welded in the absence of motion. Add
>> pressure and heat to speed the process, and you get diffusion
>> bonding. Here are some references to diffusion bonding stainless
>> steel:
>>
>> <http://scholar.google.com/scholar?q=diffusion+bond+stainless+steel&hl=en&lr=&btnG=Search>
>>
>>
>> I don't know if this type of bonding plays a role in headsets and
>> bottom brackets.
>>
>
> Find one that's steel-to-steel.

A slight modification of the search terms...

<http://scholar.google.com/scholar?hl=en&lr=&q=diffusion+bond+%22steel+to+steel%22&btnG=Search>

I looked at the first link returned. Or perhaps you prefer...

<http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TW2-3YWX3V2-3H&_coverDate=03%2F31%2F2000&_alid=521906506&_rdoc=1&_fmt=&_orig=search&_qd=1&_cdi=5550&_sort=d&view=c&_acct=C000014439&_version=1&_urlVersion=0&_userid=209810&md5=455395599933954c66bdb122b2ac330c>

From that paper:

"Crucible S7 tool steel was... prepared in a vacuum hot press using
bond conditions of 1100°C and 10, 5 and 20 MPa (Samples 1, 2 and 3)
for 20 min."

I can't read either -- the first is illegible, the second requires
membership.

In any case, yes, you can bond steel to steel in a vacuum, even
without all the temperature and pressure, I knew that, but that isn't
going to happen in a bottom bracket bearing.

really? how'd you figure that? actually, it can happen in a bottom
bracket bearing cup, just like it's one of the mechanisms in false
brinelling. but you knew that too didn't you.

http://en.wikipedia.org/wiki/Cold_welding
"Exposure to oxygen or certain other reactive compounds produces surface
layers which reduce or completely eliminate the cold welding effect.
This is especially true if, say, a metal oxide has mechanical properties
similar to those of the parent element (or softer), in which case
surface deformations do not crack the oxide film."

you-know-who said:
"stainless doesn't cold weld. titanium does. like i said, you need to
look into solid state diffusion some time. "

Peter Cole said:

From:
http://www.welding-advisers.com/PRACTICAL_WELDING_LETTER-PracticalWeldingLetterNo10.html

Quoted message said:

"Metals and alloys that exhibit very low
solubility for interstitials (such as aluminum-, iron-, nickel-, and
cobalt- base alloys) are not readily diffusion bondable."

Thanks for the link, Peter. I never thought about the relationship
between solubility and diffusion bonding. It makes some sense, though;
low solubility should lead to low diffusion coefficients.

We have different perspectives on diffusion bonding. You imply that
using interlayers or vacuum makes a process exotic, but I think those
things are normal. And those aspects are part of the reason that I think
of diffusion bonding as expensive.

Not that any of this has anything to do with bikes. Well, maybe one
could make a stronger bike by diffusion bonding the frame. No residual
stress, no heat affected zone, etc. Time for a patent! :^)

--
Dave
dvt at psu dot edu

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Quoted message said:

Quoted message said:

> Here's a link for the patent with more legible text:
>
> <http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=3444608.PN.&OS=PN/3444608&RS=PN/3444608>

Quoted message said:

I still can't read either.

I'm sorry that none of the links worked for you.

This is a known "jim beam" evasion - when confronted with documentary
evidence that directly contradicts him, he claims that there is
something wrong with the text and he cannot see it or open the link or
read the file, etcetera.

FWIW the patent link isn't working for me either.

cheers,
clive

In article
<[email hidden]>,

Peter Cole said:

dvt said:

Peter Cole said:

dvt wrote:
> Peter Cole wrote:
>> dvt wrote:
>>> <http://scholar.google.com/scholar?hl=en&lr=&q=diffusion+bond+%22steel+to+steel%22&btnG=Search>

Quoted message said:

>>> <http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TW2-3YWX3V2-3H&_coverDate=03%2F31%2F2000&_alid=521906506&_rdoc=1&_fmt=&_orig=search&_qd=1&_cdi=5550&_sort=d&view=c&_acct=C000014439&_version=1&_urlVersion=0&_userid=209810&md5=455395599933954c66bdb122b2ac330c>

Quoted message said:

>> I can't read either -- the first is illegible, the second requires
>> membership.

Quoted message said:

> Here's a link for the patent with more legible text:
>
> <http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=3444608.PN.&OS=PN/3444608&RS=PN/3444608>

Quoted message said:

I still can't read either.

I'm sorry that none of the links worked for you. You have the patent
number (3444608), and there are lots of sources to see patents online.
Maybe you can find one that works for you. Regarding the journal
article, I'll also give you the reference info [1]. If you're so
inclined, you can look it up.

Quoted message said:

> Welding and brazing are quite effective
> and typically cheaper. Perhaps that's why we rarely hear about
> diffusion bonded steel parts.

Quoted message said:

All the cases I've see with steel-to-steel involved vacuum or coatings
or were forms of friction welding. Some metals will readily
cold/diffusion weld to themselves or each other, but steel-to-steel
seems to be a case that's different. I would think that if "jb" (not
"JB"😉 was a real metallurgist he would not only know that but know why
as well.

I've hypothesized one possible reason: steel to steel joints are easily
welded or brazed, and those processes are often cheaper than diffusion
bonding. From the reading I've done, diffusion bonding seems to be
applied mostly where those other methods don't work.

Sorry to get so far OT...

[1] Anton I. Lavrentyev and James T. Beals, "Ultrasonic measurement of
the diffusion bond strength," Ultrasonics, Volume 38, Issues 1-8 , March
2000, Pages 513-516

As I said, I know steel-to-steel can be done, but it's difficult,
requiring either vacuum and/or interlayers.

From:
http://www.welding-advisers.com/PRACTICAL_WELDING_LETTER-PracticalWeldingLetterNo10.html

"The process is most commonly used for titanium in the aerospace
industry and sometimes it is combined with Superplastic Forming (a
special hot forming procedure). Ceramics can be diffusion bonded to
themselves and to metals. Metals and alloys that exhibit very low
solubility for interstitials (such as aluminum-, iron-, nickel-, and
cobalt- base alloys) are not readily diffusion bondable. However
practically any metal combination can he joined by diffusion bonding
using suitable interlayers."

The problem is in getting the metals to contact each other through the
ever present surface layers of oxides/contaminants. Also, by its very
nature (diffusion), diffusion bonding takes significant time. Both of
these issues make it very difficult for me to believe it is the major
mechanism of fretting in steel ball bearings.

Jobst makes a good case for headset damage by way of
surface welding. On a long downhill run not turning the
bars, vibration drives the lubrication out from the
bearing contacts. Then the vibration welds the two
metal surfaces and breaks them apart repeatedly.

--
Michael Press

Clive George said:

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Quoted message said:

>> Here's a link for the patent with more legible text:
>>
>> <http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=3444608.PN.&OS=PN/3444608&RS=PN/3444608>

> I still can't read either.

I'm sorry that none of the links worked for you.

This is a known "jim beam" evasion - when confronted with documentary
evidence that directly contradicts him, he claims that there is
something wrong with the text and he cannot see it or open the link or
read the file, etcetera.

FWIW the patent link isn't working for me either.

cheers,
clive

Dear Clive,

It kinda-sorta works in Explorer with QuickTime.

patft.uspto.govnph ParserOpen ↗

"Full text" is not available, so you have to click on "images."

On the left on the new screen, you get forward-backward yellow-button
arrows to navigate through the 6 pages of drawings and text.

Cheers,

Carl Fogel

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Quoted message said:

FWIW the patent link isn't working for me either.

Dear Clive,

It kinda-sorta works in Explorer with QuickTime.

patft.uspto.govnph ParserOpen ↗

"Full text" is not available, so you have to click on "images."

On the left on the new screen, you get forward-backward yellow-button
arrows to navigate through the 6 pages of drawings and text.

Nope, still not working for me. I've got quick time, IE6, those yellow
buttons, but nothing inside the main box (the tiff file).

Ah - it needs a TIFF plug in. Grrr. I believe that would sort it - or I
could use one of the other patent searches, eg espacenet.

cheers,
clive

dvt said:

Peter Cole said:

From:
http://www.welding-advisers.com/PRACTICAL_WELDING_LETTER-PracticalWeldingLetterNo10.html

Quoted message said:

"Metals and alloys that exhibit very low solubility for interstitials
(such as aluminum-, iron-, nickel-, and cobalt- base alloys) are not
readily diffusion bondable."

Thanks for the link, Peter. I never thought about the relationship
between solubility and diffusion bonding. It makes some sense, though;
low solubility should lead to low diffusion coefficients.

We have different perspectives on diffusion bonding. You imply that
using interlayers or vacuum makes a process exotic, but I think those
things are normal. And those aspects are part of the reason that I think
of diffusion bonding as expensive.

Not that any of this has anything to do with bikes. Well, maybe one
could make a stronger bike by diffusion bonding the frame. No residual
stress, no heat affected zone, etc. Time for a patent! :^)

Well, the original debate was over whether BB bearing wear was from
fretting/galling or cold/diffusion bonding. My comments(context) weren't
really about the economics or even feasibility of cold/diffusion
bonding, just on the likelihood of it being the wear mechanism in a BB
bearing.

Clive George said:

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Quoted message said:

FWIW the patent link isn't working for me either.

Dear Clive,

It kinda-sorta works in Explorer with QuickTime.

patft.uspto.govnph ParserOpen ↗

"Full text" is not available, so you have to click on "images."

On the left on the new screen, you get forward-backward yellow-button
arrows to navigate through the 6 pages of drawings and text.

Nope, still not working for me. I've got quick time, IE6, those yellow
buttons, but nothing inside the main box (the tiff file).

Ah - it needs a TIFF plug in. Grrr. I believe that would sort it - or I
could use one of the other patent searches, eg espacenet.

cheers,
clive

Dear Clive,

Aaargh! You're right. I installed their tiff-add-in so long ago that I
forgot about it.

You can get the tiff-lug-in from the patent site here for Windows,
Apple, and Linux:

http://www.uspto.gov/patft/help/images.htm#req

Cheers,

Carl Fogel

Peter Cole said:

jim beam said:

Peter Cole said:

dvt wrote:
> Peter Cole wrote:
>> dvt wrote:
>>> [email hidden] wrote:
>>>> http://www.read-wca.com/pwm.cfm
>>>
>>>> From what this article surmises, one
>>>> can imagine that two optically smooth pieces of steel would in time
>>>> become welded if resting on one another. That does not occur
>>>> without
>>>> motion between the two.
>>>
>>> I think they *would* become welded in the absence of motion. Add
>>> pressure and heat to speed the process, and you get diffusion
>>> bonding. Here are some references to diffusion bonding stainless
>>> steel:
>>>
>>> <http://scholar.google.com/scholar?q=diffusion+bond+stainless+steel&hl=en&lr=&btnG=Search>
>>>
>>>
>>> I don't know if this type of bonding plays a role in headsets and
>>> bottom brackets.
>>>
>>
>> Find one that's steel-to-steel.
>
> A slight modification of the search terms...
>
> <http://scholar.google.com/scholar?hl=en&lr=&q=diffusion+bond+%22steel+to+steel%22&btnG=Search>
>
>
> I looked at the first link returned. Or perhaps you prefer...
>
> <http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TW2-3YWX3V2-3H&_coverDate=03%2F31%2F2000&_alid=521906506&_rdoc=1&_fmt=&_orig=search&_qd=1&_cdi=5550&_sort=d&view=c&_acct=C000014439&_version=1&_urlVersion=0&_userid=209810&md5=455395599933954c66bdb122b2ac330c>
>
>
> From that paper:
>
> "Crucible S7 tool steel was... prepared in a vacuum hot press using
> bond conditions of 1100°C and 10, 5 and 20 MPa (Samples 1, 2 and 3)
> for 20 min."
>

I can't read either -- the first is illegible, the second requires
membership.

In any case, yes, you can bond steel to steel in a vacuum, even
without all the temperature and pressure, I knew that, but that isn't
going to happen in a bottom bracket bearing.

really? how'd you figure that? actually, it can happen in a bottom
bracket bearing cup, just like it's one of the mechanisms in false
brinelling. but you knew that too didn't you.

http://en.wikipedia.org/wiki/Cold_welding
"Exposure to oxygen or certain other reactive compounds produces surface
layers which reduce or completely eliminate the cold welding effect.
This is especially true if, say, a metal oxide has mechanical properties
similar to those of the parent element (or softer), in which case
surface deformations do not crack the oxide film."

and when asperities break through each others layer, they can still cold
weld.

Quoted message said:

you-know-who said:
"stainless doesn't cold weld. titanium does. like i said, you need to
look into solid state diffusion some time. "

quoting out of context doesn't do much for credibility. maybe i should
have written "stainless doesn't 'cold weld'" since i was quoting the
other "you-know-who" and his mistaken assumptions for its circumstance,
but that doesn't invalidate what i said.

btw, since titanium so readily passivates, [oxide layer], perhaps you'd
like to inform the class on why exactly it still manages to stick to
itself so readily.

Peter Cole said:

dvt said:

Peter Cole said:

From:
http://www.welding-advisers.com/PRACTICAL_WELDING_LETTER-PracticalWeldingLetterNo10.html

Quoted message said:

"Metals and alloys that exhibit very low solubility for interstitials
(such as aluminum-, iron-, nickel-, and cobalt- base alloys) are not
readily diffusion bondable."

Thanks for the link, Peter. I never thought about the relationship
between solubility and diffusion bonding. It makes some sense, though;
low solubility should lead to low diffusion coefficients.

We have different perspectives on diffusion bonding. You imply that
using interlayers or vacuum makes a process exotic, but I think those
things are normal. And those aspects are part of the reason that I
think of diffusion bonding as expensive.

Not that any of this has anything to do with bikes. Well, maybe one
could make a stronger bike by diffusion bonding the frame. No residual
stress, no heat affected zone, etc. Time for a patent! :^)

Well, the original debate was over whether BB bearing wear was from
fretting/galling or cold/diffusion bonding. My comments(context) weren't
really about the economics or even feasibility of cold/diffusion
bonding, just on the likelihood of it being the wear mechanism in a BB
bearing.

eh? no it wasn't. it was about whether bottom bracket cups seized
because of some hitherto unknown form of pressure-induced melting.