32 replies to this topic

[desmo]

Since MMCs(Metal Matrix Composites) are apparently legal for internal engine parts as long as they don't contain CF(Carbon Fiber) or aramids, depending on the methodologies employed to determine the specific modulus(stiffness against density) of a material under scrutiny, significant ambiguities could be interpreted into the limit on specific modulus.

If I wanted to sail close to the wind as far as that reg goes, and why wouldn't I if it allowed weight savings in a critical reciprocating part, I'd like to know whether an MMC can contain particles, say boron or ceramic, which exceed the modulus limit or is it the modulus of the whole part that which is limited. If these are permitted, following the same logic could a preform of higher modulus be used in say a ring land or the crown area as long as the part as a whole was inside the limit? Might the modulus of the part be considered the average value of a single piece? Or the sum of it's constituants? And if so then by volume or mass?

Then there's the issue of anisotropy(mechanical properties that aren't equal in all directions), which raises a similar set of potential ambiguities: What if a part exceeds the specified limit when measured on one axis, but is safely within the limit on other axes? What if such an anisotropy is internal and local inside the part? How on earth do you definitively measure that? Does the scrutineer saw the part in question into tiny pieces and test each piece on 3 or more axes?

It seems it is only possible to measure the average modulus of the part unless you really want to make your life difficult as a scrutineer. I've read that a pretty accurate measurement of non-specific modulus can be done non-destructively by ultrasound analysis. Do that, toss the part in a graduated beaker of water to determine volume, then weigh it to get a specific modulus number looks like a good approach if I am scrutineering. Pardon my logic(?), I grew up in a family of acedemics and laywers!

[david_martin]

The elastic moduli of the additive particles is higher than the parent Aluminium, thats kind of the point The specific stiffness is specified for the bulk material.

The most common particles used in Aluminium MMC's are either silicon carbide or alumina, typically morpholgies are spheroids or whiskers. They are present in the Aluminium parent matrix as discrete particles. There are difficulties in getting a number of potential materials to "wet" and mix in the aluminium melt during casting - you can wind up with a lot of segregation and internal voids around the particles. This can have a really detrimental effect on the fatigue perfomance of the MMC.

There will be a degree of anisotropy in an Al-MMC, although deliberately engineering elastic anisotropy in a cast MMC is very hard in practice. That implies that you could can control the orientation of the particles in the melt. It might be possible to encourage a desired particle orientation through thixoforming the MMC, and it might also be possible using magnetic fields, if you had a selectively ferromagnetic particle at typical melt temperatures (600-650 celcius, although none of the common particles I know of are ferromagnetic under any conditions). You can measure the elastic modulus of a material through accoustic emission techniques - the speed of sound in solids in related to the elastic modulus. I would imagine that the tests would, however, be done on test specimens manufactured under the same conditions as the engine components using conventional mechanical testing equipment.

[desmo]

David- Thanks for picking up the ball on this thread, I was afraid the topic might prove too esoteric for anyone.

I didn't mean that the additives to the MMCs would have a higher specific modulus than the parent metal(of course they would or what's the point!), but if they had a higher modulus than the specified maximum of 40GPa/(g/cc)^2. I cannot find an exact wording of the limit on modulus, but I understand that the limit only applies to metallic materials so presumably any additives would fall outside the scope of the limit as long as the composite as a whole was within the limit.

It appears to me, however, that it may be possible to engineer MMCs with locally higher moduli through seeded castings or the incorporation of local preforms into the casting. As well, it appears that useful engineered anisotropy might be possible through orienting additives with rod or whisker-like morphologies, as well as anisotropic preforms.

It would thus seem that the regulation on modulus does not specifically address either the issues of local modulus or anisotropies. The ambiguity might thus provide a path for engineering materials that exceed what could be achieved through the essentially isotropic metallic materials the regs seem designed to address!

[imaginesix]

It is my understanding that the specific modulus rule is enforced by chemical analysis of components, probably at random locations on randon parts.
I suspect the companies developing these parts simply submit samples to the FIA, or chemical compositions for them to make samples, which are tested once for stiffness, and approved or rejected. Then only the chemical composition needs to be tested to determine legality.
Makes sense?

[desmo]

How would knowing the chemical composition of a non-homogenous or anisotropic composite help determine it's specific modulus? Unless you presume that additives no matter how small in amount or proportion to any composite must also meet the modulus limit. This interpretation could really put a lid on MMC applications.

[imaginesix]

I don't know what is meant by 'additive' when referring to metal alloys, so I may be missing a chunk of the argument here. Is silicon carbide an example of what you refer to as an 'additive'? Is it impossible to test for ALL additives?
Apart from that, it seems clear to me that determining the chemical composition of a suspect alloy would allow the FIA to relate the specific stiffness of the material. Remember that the stiffness of the actual parts are not regulated, rather it is the stiffness of the material used to make them. So determining the composition of the alloy used in a PART allows the MATERIAL to be lab-tested for stiffness with great precision.
The issue of non-homogenious blends is resolved if one assumes the FIA may sample any amount of material on a part, at any location on or within it, down to a minimum sample size determined sufficient to provide statistical accuracy.
Am I missing anything?

[desmo]

The question then becomes, it seems to me, is an Al matrix MMC with reinforcing particles 3 microns in diameter a single material, or is it considered a combination of discrete materials each part of which is subject to the same specific modulus criteria? If the latter, it reduces the scope allowable materials drasitcally. And if that is the logical path that one chooses to persue, does that mean any alloy of Al/Be would be de facto illegal because the Be componant of it's composition is in excess of the specified modulus limit regardless of the physical properties of the resulting alloy? And likewise, would a material that exhibited significant anisotropy either by dint of it's internal crystaline or grain structure or due to oriented reinforcing additives which was within the limit on 2 of 3 axes necessarily be illegal? Or an alloy forging whose modulus is close to the limit might exhibit microscopic areas of anisotropy in excess of the limit due to grain alignment from the forging process. Or perhaps a heat or cryogenic treatment after the piece is formed? How would you propose to regulate that? Merely specifying the material's chemical composition and attaching an assumed specific modulus to it based on that alone seems a wholly inadequate means of defining legality or illegality to me.

[imaginesix]

I think I get the gist of your question finally.
In the April/May 1999 issue of Race Tech, they rate the legality of various combinations of alloys based on their stiffness as alloys.
Besides, if the rules don't specify the method of measurement, (I don't know that they DO), they must be interpreted in whichever way provides the greatest performance advantage.
As far as variable stiffness ratings based on the internal crystaline or grain structure and any microscopic areas of anisotropy, those spell 'weak spots' in my view.
I can only offer my opinion from the point of view of an outsider looking in, but surely the science of metallurgy is able to control the process or modify it's product sufficiently to prevent anything more than very localised imperfections from weakening the material.
After all, if it could not be well controlled, it would be unsuited to development for racing.
In addition, I recall reading (though I can't find the source) that the stiffest useable material that had been developed to meet the new rules was only some 95% or so of the maximum allowed stiffness. Surely this provides a large enough error margin for 'extra stiffness'?

[desmo]

I imagine that alloys or other materials are being or have been developed that much more closely approach the specified limit than that. The upside is just too large. Torsional crank vibrations are a very real problem in F1 and once one has exhausted other means of addressing this, the reduction of mass in the piston and gudgeon/piston/wrist pin are the most promising path for addressing the TV problem. Even a reduction of mass as little as a gram per cylinder would be very significant.

As for "variable stiffness ratings based on the internal crystaline or grain structure and any microscopic areas of anisotropy" spelling weak spots, this is not necessarily the case. Indeed forged crankshafts and other parts are engineered to use anisotropies to achieve a desired effect and have been for decades.

There are very clever people working on creating materials and parts that walk right up to the ragged edge of the regulations on specific modulus as we speak. You won't be able to look up the properties of these new materials in any book or table. Some sort of standardized testing methodology must be devised so that the rule can be enforced in a fair and accurate way.

[david_martin]

There seems to be a few misconceptions that have surfaced in this discussion that need to be addressed. This is going to take a while, so I will try to do it in several "installments".

Firstly, the modulus number that is at the core of this discussion will undoubtedly be quoted for the bulk material. The specification will be applied to the MMC as whole and not for any individual internal components which make up the MMC. That a MMC, or any other material for that matter, could and conceivably would contain additions of materials with properties which exceed the specification, is of little consequence. The properties can only be measured for the bulk material, and that is the way they are universally specified.

Next installment: Isotropy and Elastic properties of metals.

[Halfwitt]

Is this rule actively enforced or tested for at all. I would imagine that an engine strip at the track for the FIA would be almost unprecedened, especially if it involved handing over engine parts. It is my guess that the rules rely on a large amount of 'sporting behaviour' from the teams. I imagine that it would be easy to use an illegal material internally on an engine without it ever being detected.

[desmo]

David, I can hardly wait. Your input is appreciated.

Do I sense another "unenforceable" regulation has arrived? Really the subtext of my posts is a suspicion that this rule might prove unworkable against a determined attack from a motivated and skilled attempt(not mine!) to find and exploit potential ambiguities. I think Halfwitt may be correct in asserting that a degree of "goodwill" from the teams may be required to enforce this rule and the minute suspicions of non-compliance arise and political pressures surface, the scrutineering may prove unworkable.

Knowledgeable observers within the sport recognized the ultimate futility of the TC regulations from their very inception and in retrospect it wasn't good for the sport to have regs that aren't enforceable with a very high degree of confidence. Same issues arise as TC. It ends up with controversy and unprovable accusations and suspicions of cheating. Then the workarounds turn out to be massively more expensive than the issue the regs address, penalizing the teams with the least resources and defeating the original intent of the regulation which seems to primarily be cost containment.

[AidanCB]

Hope you don't mind me throwing my 2 pence worth in.

Regarding the specific modulus limits that apply to MMC's and metal alloys, this is set such that it eliminates the use of lithium (Li) and beryllium (Be) in these alloys. Al-Li alloys can be exceptionally strong and light, similarly Be additions would reduce density. The worry is over the safety of these alloying additions! Be and Be-Oxide are incredibly toxic, and both Be and Li are dangerous to work with in elemental form. The concern also lay with what happens to the alloy in a very hot fire - would/could (very) toxic chemicals be released?

Alot of the testing is done by each team and they submit the results to the FIA, who may or may not want to see more (if I remember correctly). Had a materials engineer from BAR give a lecture last year on his role in testing the CFRP's and impact testing of the cockpits, I'm sure that was what he said. As we numbered several metallurgists/ceramists in the audience we wanted some info on MMCs/CMCs such that he gave us the the reasons for the property restrictions.

Not sure how the proerty regs apply to coatings though. It is possible to apply a thin (few micro- or nanometre thick layer) of ceramic to material, and that surface layer could have a very high elastic modulus. I know Williams had some suspension failures a couple of years ago that were related to a ceramic-like coating on a ball joint.

[david_martin]

Isotropy and elasticity in metals

In service, most engineering components are designed only to operate only under elastic strains - that is to say they are not intended to experience any permanent shape change during their service life. As a result, the following discussion concerns itself only with metal elasticity. Plasticity can wait for another day

In most crystalline materials, the phenomena of elasticity occurs as a result of atomic level interaction between neighbouring atoms in the characteristic unit cell (building block) from which the crystalline material is composed. Most common engineering metals (Irons and Steels, Copper, Aluminium, Titanium) take a cubic unit cell (either face- or body- centred), which is axisymmetrical, and as a result, has little elastic anisotropy. That is to say that the metals elastic properties are no strongly dependent on the orientation of the unit cell because the distance between atoms in the unit cell is roughly equal in all directions. Therefore, the internal crystallographic orientation within metals such as Aluminium and Iron does not have a large influence on the bulk elastic properties or bulk elastic isotropy.

This is also why just about all alloys of a given metal have very similar elastic properties. The elastic behaviour of the alloy is a function of interatomic forces between atoms in the unit cell. If the alloy is still composed from a given unit cell of a given atom, it will have the elastic properties dictated by that unit cell and atom. Hence just about all ferrous alloys (cast iron, low carbon steel, tool steel, and many stainless steels) have broadly similar elastic properties - they are all mainly Iron, and derive their elastic behaviour from the parent Iron unit cell.

Next installment: A closer look at Aluminium Metal Matrix Composites

[AidanCB]

Be careful when you're talking about steels! Depending on the alloying additions steels can have either a body-centred- or face centred-cubic unit cell, the elastic properties of which can be very different. That's also assuming equilibrium cooling and not any quenching leading to the formation of martensite or bainite which have significantly different properties from equilibrium processed steels!

Some alloys have individual crystals that are anisotropic, but when one of thousands of thousands of crystals all at random orientations the bulk properties appear isotropic. Although careful processing can lead to anisotropy in the bulk material if desired!

[david_martin]

Originally posted by AidanCB
Be careful when you're talking about steels! Depending on the alloying additions steels can have either a body-centred- or face centred-cubic unit cell, the elastic properties of which can be very different. That's also assuming equilibrium cooling and not any quenching leading to the formation of martensite or bainite which have significantly different properties from equilibrium processed steels!

Some alloys have individual crystals that are anisotropic, but when one of thousands of thousands of crystals all at random orientations the bulk properties appear isotropic. Although careful processing can lead to anisotropy in the bulk material if desired!

Thanks for you comments. This "series" is meant to debunk a few myths and provide a bit of information about the materials that have become such hot topics in F1 circles recently. As such, it is not intended to be a dissertation on the physics of materials, just a sketch of some basic concepts which should give a bit more insight into the question which started this thread. I guess I could have recommended everyone read the first six volumes of the ASM Metals Handbook, bit I though this might be a bit more accessable.

A few comments of my own:

The actual difference in elastic properties between BCC ferrite and FCC austenite is not very large, typically less than 10%. The characteristic unit cell volume change between the two is only around 7.5%, off the top of my head. Bainite is just ultra fine acicular ferrite and has exactly the same elastic properties as conventional polygonal ferrite. I deliberately neglected ferrous martensite to keep things simple. Obviously body centred tetragonal martensite is rather different to either BCC or FCC iron, although the difference in actual elastic properties is not all that large. Your second point about texture and crystal orientation in polycrystalline materials is, I believe, far more relevent to metallic plasticity where dislocation mobility becomes crucial.

[AidanCB]

After a bad days mechanical testing yesterday I flew into that one a bit quick (measured elastic modulus of the material I'm working on was a fraction of that predicted by reliable models!). I appreciate what you've said having thought it through, yes you've explained everything very well, better than my lecturers did in my first year at university and in a fraction of the time!

But some alloys do exhibit elastic anisotropy, the material I'm working on for one.

Anyway, keep up the interesting topics. Some of your posts have made for good revision sessions for me!

With regards to testing and scrutineering, having located my notes from the lecture given by the chap from BAR this is what I can remember:

The FIA regulations gave the property limits for various classes of materials e.g. maximum elastic modulus or minimum strength but it was up to the teams to test the materials. FIA provided information on loading rates and sample sizes. The teams essentially had to design the tests themselves for certain components. Thus the teams were required to give the results plus details of the test methods and reproduceablility.

Now I'm pretty certain that the specific properties of the metallic/ceramic base materials was set to preclude the use of lithium and beryllium because of their potential toxicity (had a Beryllium leak in the building on my first day at work in one institute in Europe - not nice). This unfortunately rules out many more novel materials that are plausible. As a result the metallurgy of components in F1 isn't particularly ground breaking relative to the advances in carbon-fibre based composites (CFRPs). Certain aluminium-lithium (Al-Li) alloys have specific properties very similar to the carbon fibre composites and in fact are better in compression. Consider this: if certain external components of the car were made from Al-Li alloys, during an accident there is a likelihood of significantly less debris flying about in to the crowd because the alloy would fail through plastic deformation rather than fracture. This would give a "graceful failure" hopefully reducing the risks to spectators and marshalls.

Sorry David for any offence caused,

regards Aidan

[desmo]

"The FIA regulations gave the property limits for various classes of materials e.g.
maximum elastic modulus or minimum strength but it was up to the teams to test the
materials. FIA provided information on loading rates and sample sizes. The teams
essentially had to design the tests themselves for certain components. Thus the
teams were required to give the results plus details of the test methods and
reproduceablility."

This is absolutely the first I've heard of this. Has anyone else ever heard of "property limits for various classes of materials" contained within the FIA regs or, in fact, anywhere else?

And allowing the teams to specify the testing methodology seems like an invitation to "creative" testing doesn't it?

[MacFly]

Are single crystal alloys like CMSX-10 legal in engine parts?

[david_martin]

I thought I would pose this teaser while I am getting my act together - bonus points if anyone can ID them

http://www.geocities...rtin70/mmc.html

I have put it into a scrap of html to overcome limitations with geocities. Click on the url to have a look.

[desmo]

MacFly, as I understand it all alloys are legal as long as they comply with the limit on specific modulus.

[AidanCB]

"The teams
essentially had to design the tests themselves for certain components. Thus the
teams were required to give the results plus details of the test methods and
reproduceablility."


Sorry, let me clarify what I meant, 'cos that was badly worded!

Material properties like the elastic modulus I assume would be tested to the usual standards used in industry. Four main ways to measure elastic modulus: in tension, compression, bending or using acoustic methods. Each method may give slightly different results but the relative ranking of these methods is pretty consistent and as long as sample size and loading rate are stated all is well! Given a compositional analysis of an alloy or composite and processing history, one can normally get a good estimate of properties from modelling.

For larger components or substructures is, from what I remember, where the teams developed their own tests which would then be approved by the FIA.

[david_martin]

Aluminium Metal Matrix Composites

So what the heck are metal matrix composites anyway?

Metal Matrix Composites (MMCs) are essentially a metal which contains some kind of reinforcing agent which modifies its physical properties. MMC are distinct from convetional metals and alloys, because the reinforcing agent is insoluble (it does not dissolve) in the parent metal. Nearly all important MMCs are based on the common light metals - Aluminium and Magnesium. Apart from their low density, Al and Mg have low melting temperatures which suit the way MMCs must be made. The MMCs which appear to be finding their way into F1 engines are Al based.

The reinforcing agents used in MMCs come in two major families - particles and fibres. Particle reinforced MMCs contain spherical ("orange" or "egg") shaped discrete particles, while fibre reinforced MMCs contain discrete, "semi discrete" or continuous networks ("spaghetti" or "shoelaces") for want of a better expression) of reinforcing fibres. In Aluminium MMCs, Alumina seems to be the reinforcing material of choice, both in particle and fibre reinforced types. The reinforcing fibres are typically 3 to 20 microns (millionths of a metre) in diameter, and particles 15-100 microns in diameter. To provide a frame of reference, human hair is typically 25 microns in diameter.

Getting the reinforcing agents into the MMCs is definitely the biggest trick to getting them to work. Particles are relatively simple, just mix into to either molten aluminium or aluminium powder and cast or sinter - similar to adding aggregate to concrete. Fibre reinforcement is more complex. One of the most common methods is through the use of what are called preforms. Preforms are premanufactured networks of fibres which are then cast into the metal under pressiure or compacted into powder and sintered - similar to reinforcing bar in concrete.

Cue my picture link (apologies to those who tried to view the picture when I posted it and could not).

http://www.geocities...rtin70/mmc.html
taken from Atzori, C,. Pinna, I., and di Russo, E., "The indirect squeeze casting process of short fibre reinforced Al-matrix composites", presented at the ASM International Conference on Light Metals, held in Amsterdam, 20-22 June 1990.

The photo on the left is a scanning electron microscope image of an Alumina short fibre preform for use in an engine conrod. It has been taken at a magnification of 400 times. Each fibre is about 3 microns in diameter. The photo on the right is an optical micrograph of the final Al MMC taken at 200 times magnification. The dark spots and lines are the reinforcing fibres and the light coloured material is the parent Al. You can see that there is a reasonable amount of directional alignment of the fibres in the pre-form and the final MMC, although there is still quite a lot of randomly oriented fibres.

Next installment - What are the properties of MMC's like and why use them in F1 engines

[imaginesix]

Thank you for these highly eductaitve posts, d_m.

Already you have helped clarify the issue immensly as far as I am concerned. I had failed to comprehend that MMC could have such a high degree of directional variance in stiffness.

I conclude then, that a given material's stiffness is rated based on whichever direction it's stiffness is highest.

Otherwise, it's akin to specifying a minimum height for the underside of the sidepods, but only measuring it at the highest spot, allowing the rest of the sidepod to sit very low. What would be the point then of the regulation?

If you have any more installments left, be secure in the knowledge that I for one would love to read them.

[david_martin]

Nice to know that I have an audience - of at least one

There is more to come, but I have been a little distracted by other things for a few days. I planned to talk a little about the properties of Al MMC's and how to test them, and then finally how the FIA probably would go about scrutineering of materials like these in engines. That should take us back to Desmo's original question. Hopefully this all week

[desmo]

Can't wait. I always enjoy reading your posts David.

[david_martin]

Properties of Aluminium MMCs

Better late than never, as they say

In one sentence, Aluminium MMCs offer the following advantages over conventional Aluminium alloys:

• increased strength
• improved strength at elevated temperatures
• improved stiffness
• reduced thermal expansion
• improved fatigue resistance

As the stiffness, quoted using a Young's modulus value, has been the primary focus of this thread, that is where this post will concentrate.

In numbers, it is possible to achieve Young's Moduli values over 125 Gpa (quoted for a 25% long delta-Alumina fibre reinforced Al MMC tested in a direction normal to the fibre direction), as compared with around 70 GPa for unreinforced alloys. This translates to a specific stiffness (the number the FIA is prescribing to outlaw Beryllium alloys), of over 46.3 Gpa/gramme/cm^3.

The reason for this enormous increase in Young's Modulus is rather simple - the reinforcing fibres have Young's Moduli in the range of 180-300 GPa. The Young's Modulus value of a fibre reinforced MMC will be somewhat less than that calculated by the law of mixtures, ie:

E(MMC) = fibre fraction x E(Fibre) + [1 - fibre fraction] x E(Al)

I say somewhat less, because the orientation of the fibres will be less than ideal, and hence the effective fibre fraction in the testing direction will be less than the theoretical value. Obviously the increase in Young's Modulus for a random network of fibres or discrete particles will be far lower than a highly oriented semi-continuous network of fibres. It should also be fairly apparent than controlling the fibre type, volume fraction, and orientation will allow the possibility of "engineering" an MMC to give the properties that are desired, including a maximum specific stiffness that would be right on the FIA maximum value.

So is a fibre reinforced MMC anisotropic? The answer is undoubtedly yes. The degree of anisotropy will be a very strong function of the fibre orientation within the MMC. To quote some room compressive strength numbers, the same 25% fibre continuous reinforced Al-MMC exhibited a compressive strength of around 900 MPa when tested in a direction normal to the reinforcing fibres (or around +100% compared to the parent Aluminium), but only about 450 MPa in a direction perpendicular to the reinforcing fibres(or around +10% compared to the parent Aluminium).

Does this anisotropy cause something of a conundrum for materials testers? The answer is no. Materials are, almost without exception, tested in a way which characterises their maximum desirable properties. Anisotropic materials designed for high strength or stiffness are tested in an orientation that yields the highest strength or stiffness. Anisotropic materials designed for high ductility are tested in an orientation that yields the maximum ductility. For the case of Aluminium fibre reinforced MMC's, bulk samples will be tested with load applied in the same direction as the predominant orientation of the reinforcement fibres.

This is probably a convenient place to stop. Stay tuned for the final installment "A testing and scrutineering model for engine components".

[Halfwitt]

David,

I would think that most of the Aluminium components within an engine are either cast or forged. Are fibre reinforced MMC's used in these applications, or do you think the particulate type would be used?

[david_martin]

Fibre reinforcement lends itself best to primary shaping through either casting or powder metallurgy processes. The reinforcing network can be introduced into the parent aluminium as a "preform", which is a pre-manufactured bundle of fibres of a given shape and fibre orientation. The scanning electron microscope image I posted is of an alumina fibre preform for use in near net shape casting for a conrod. Preforms are usually made by binding fibres together with a small volume of an inorganic binder such as silica and firing them at elevated temperature (typically above 1000 degrees celcius). The preform is placed into the casting mold or powder die and the the aluminium parent is pressure cast or pressed around the preform. Unfired (green) powder formed parts are often hot isostatically pressed (HIP), which is similar to warm forging, to improve the part density before sintering.

There are reports in the literature of forging fibre reinforced MMCs, but the forging steps are normally only final shaping steps on a near net shaped part produced by a previous shaping process, such as casting.

[palmas]

David, I also follow this (your) posts carefully, just to read and learn, not to comment, for I would not be able to!

[desmo]

David, do you think the specific elastic modulus limit is an enforcable one given the potential ambiguities? When I asked an F1 engineer, this was his response:

"The plain answer is that the FIA have nothing in the way of enforcement for their regulations other than a set of glorified weighbridge scales, a few carboard cutouts for 'aero' checks, and a digital vernier to measure engine displacement (in fact, when was the last time anyone heard of the FIA doing a swept volume check???), O! and a rather neat spectrograph for fuel analysis (but don't ask the guy to check anything else but liquid!)."

[ehagar]

Wow. Never thought I would find a newsgroup like this on the net.
I was under the impression the 40 GPa was a bulk modulus applied to metallic parts. Otherwise carbon-carbon would be illegal. (But how you realistically test this I don't know...)

Anyway, the reason for my post. Beryllium isn't always THAT dangerous. In its particulate form,or in the 10-15 micron range, it most certainly does. I believe the first cases of Chronic Beryllium Disease came about in the 40's when factory workers processed zinc beryllium silicate.

The only significant risks, from an Engineering point of view could be in situations of wear. So a responsible user would consider areas of safety where small particulate can be generated. I see that as two potential areas.

1. the fabrication process, from machining and welding.
2. The eventual fate of the beryllium in either planned or in involuntary circumstances

In the case of engine components, didn't they use a ceremet as a wear inhibitor? Wonder how well that worked. As far as for brake calipers, I fail to see any significant risk.

I think the motorsports director at Brush-Wellman (his name at the moment escapes me) has a Aluminum-Beryllium stir stick for his coffee.

Sorry, I'm a bit of a Beryllium zealot.

[david_martin]

Originally posted by ehagar
I think the motorsports director at Brush-Wellman (his name at the moment escapes me) has a Aluminum-Beryllium stir stick for his coffee.

Sorry, I'm a bit of a Beryllium zealot.

Welcome, and may I add my voice to the list of those who think that the OH&S risks associated with Beryllium are well and truly overstated. As a total aside, but with a tenuous link to Beryllium, I had the privilege of spending a couple of entertaining hours today with a Professor from St. Peterberg State Technical University who pioneered the vaccuum rolling technique used to roll all of the Beryllium used on the now defunct Russian reusuable space vehicle project. Or as he called it the "Soviet Space Shuttle"