14 replies to this topic

[Top Fuel F1]

Who is this French firm working on this supposedly super light TI gearbox for Ferrari to be introduced later this year? I think Ferrari tried a TI box before and possibly Minardi had or has been using one. In the past I've wondered whether Ferrari was making their own gearboxes and also wondered about where the other teams were obtaining (make or buy) theirs.

[desmo]

Ferrari run a fabricated Ti gearbox case and have since at least '99, although I assume that the internal parts are mostly steel. There was some talk a year or two back that Ferrari were experimenting with Ti gearbox internals, but I never heard this confirmed. Ti gears sounds like an invitation to unreliability to me.

[RedCarFan]

unreilability? When is the last time Minardi dropped out because of gearbox failures? Ferrari do more research than any other team in to new technologies, and they would not pursue the new gear box if it would cause relaibility problems. Be sure that Ferrari will do enough testing to ensure rock-solid reliability, like the cars of the past years. These are the actions of world champions

[Top Fuel F1]

I don't know if the Minardi gearbox was/is a TI case with steel gears or if it was/is all TI. I think what desmo was expressing was that TI would not necessarily be a good material for the gearbox gears. I'd have to do more investigating before I either agreed or disagreed with that. Also Ferrari's new gearbox may or may not have TI gears. The only thing that may make one consider that it might was the comment about it being ultra light.

Rgds;

[desmo]

For more on the Minardi cast Ti gearcase I refer you to this thread which has some excellent photos of the 2000 version.

http://www.atlasf1.c...=&threadid=7795

There are huge technical difficulties to making Ti gearsets. The tribology (wear resistance essentially) of Ti on Ti sliding or rolling contacts is known to be poor, with galling and wear issues that make it an unattractive material for gears. These issues may be addressable through surface coating or treatments such as titanium nitride. I've not heard of any treatment for Ti gearsets that would be sufficient to last through a F1 race. There is also the relatively meager modulus of elasticity compared to steel to overcome. There is a website that perports to represent a company in Cambridge Mass that makes and sells Ti gears but the phone # given is 555-1212 (phony)!

[Engineguy]

Keronite surface treatment is being promoted for titanium transmission gearsets... whether or not that means anyone is already using it I don't know. Poeton (F1 cylinder bores, etc. specialists) is one of the few licensees of this process, and with their F1 connections...

The transmission gears/shafts are one of the few places left on an F1 car that could yield a significant weight relocation from a matrials substitution. Well that, and moving the cylinder head mass lower with a wider vee angle ala Renault.

[desmo]

I thought of Keronite too. The Oct./Nov. issue of RaceTech had an article on it containing the following quote from Robert Altham, chief executive of Keronite Ltd.:

"We can harden aluminium parts to make them wear resistant way beyond that of steel. However, in terms of gear sets, aluminium is unlikely to have the bulk strength for it but titanium does, so there's a real possibility of having titanium gear sets because of the Keronite coating."

Unfortunately I cannot find any independent research to back up the rather extravagant claims bandied about on this surface treatment process, so I will keep my skeptic's hat on until some data is published on it by someone who doesn't have a commercial interest in promoting the product for this application or we see it used in racing for this purpose. TiN looks to me to be another real possibility, and more of a known quantity. There are always a plethora of surface treatments promising the world being promoted. Most are never heard from again.

[FordFan]

What ever happened to that carbon fibre gear box that Stewart had. It was big time unreliable, I know, but is it still being worked on. (I've no idea how it would work, by the way.)

[Top Fuel F1]

I envision the F1 gearbox gears being close to Tool Steel (iron/steel plus up to 10% molybdenum and up to 1.5% carbon with various amounts of chromium, vanadium, tungsten and possibly cobalt). Like some of the other components in F1 we are surprised when we see how really small they can be. So the sum of the weights of these gearbox gears may not be that great in relation to the entirety of the car. The weight of the gearbox case cold be a more substantial contributor to the overall weight and therefore it is of value to make this out of TI. Of course TI will alloy with other metals except copper and AL. So who knows if some one has come up with some novel alloy that would work for gears. After all they would only have to last for one race plus a safety factor.

Although metal valve springs are not used in F1 it is TI's valuable contribution in the area of valve springs used in various other types of race cars, for instance CART and Top Fuel, that tends to make some think it would be good for many other functional uses in any type of race engine.
What makes TI so valuable (so much better than steel) in the valve spring application is it's ability to handle the stress of repeated compression without bending (taking Set). The difference is in the Yield Point and Fracture Point of the two metals. Also the TI spring has less wire in it so the solid height is much lower, allowing a higher lift cam. Although you are also saving 1/2 to 2/3rds the weight the functionality benefits are the most important reason for using TI in this application.

Rgds;

[Ray Bell]

Would a composite gear be usable?

Cut a gear as you would a ring gear, shrink it onto a Ti hub and save a heap of weight?

Just a thought...

[Billy Gunn]

In response to FordFan and Desmo,

Stewart and Arrows used a Carbon gearbox 'shell' in '98 season. The internals to all knowledge were normal trans gear steel (and more than likely purchased from one of the bespoke gear companies supplying the motorsport industry in the UK ~ Quaife, or Xtrac spring to mind). Stewart dropped the Carbon composite case in 2000 and saw an upward turn in their performance as the car for once became predictable. I remember seeing a photo of the Arrows at a test session with what appeared to be a brace bar across the rear suspension pick up points on the 'box as if they were having torsional problems. I don't know if Arrows are still pursuing the carbon composite route for the trans case.

As for Ti gears - Keronite sounds like a possible cure for the galling problems. But somebody has already run Ti gears successfully (and this one will be close to home for you Desmo!), it was BSA on their World championship Victor MX bikes back in 1967; they ran Ti con-rods, frames, and even spoke nipples on the wire wheels, but of particular interest to this discussion is that they used Silver plated Ti gearsets to overcome the galling issue. Later they went to a steel known as Maraging, for strength and lightness, this material is still pretty much 'under the sheets' stuff.

[desmo]

From what I've read, the Arrows gearcase for the A21 was a hybrid CF/Ti fabrication.

Hamidy: "at present the casing is carbon with the load bearing components in titanium.

"I believe that Ferrari is also using a hybrid structure. I think an all-carbon structure is the next generation and it is going to take a lot of work to really understand the issues and find solutions which work."

I knew I had heard the term maraging recently and it was in adverts for golf clubs, "metal woods"[oxymoron!]. Maraging steels are very low C which can be heat treated relatively quickly and at low temp via precipitation reactions to a very high proportion of martensitic structure from their untreated predominantly austentitic state. Pre-treatment they are very EDM-friendly, which is apparently how modern F1 gearsets are now machined. McLaren uses Chamilles Robofil 403051 EDMs to manufacture their gears in house capable of machining to a tolerance of 2 microns! It takes about 3 hours to machine a gear on the EDM. I've seen published yield strengths of 2000MPa (290Ksi) for maraging steels which is to me astonishing. These steels seem to have emerged from "under the sheet" and are widely available now, and indeed there seems to be a cadre of speculators that deal in these steels as investments now!

As a BSA lover, I am delighted and astonished to hear that they were using advanced materials such as maraging steels and Ti way back then for their factory bikes. I know they were introducing Ti con rods on the DFV around this time. I wonder what alloys the boys at BSA had access to back then. I had thought that CP was all that was commercially available back then, no good 3Al/2.5V or 6Al/4V and such. Silver plating Ti! Wow! I know that prolonged contact between Ti bits is an invitation to seizure and have heard the process described as cold welding. I suppose any plating would help there, but I didn't know silver plate was tough enough for gears. An English firm, Hope has manufactured Ti cogsets for mountain bicycles treated with TiN that seem to hold up quite well in this surprisingly rigorous application (think mass grit and contact with a steel chain.)

[david_martin]

Originally posted by desmo
FI knew I had heard the term maraging recently and it was in adverts for golf clubs, "metal woods"[oxymoron!]. Maraging steels are very low C which can be heat treated relatively quickly and at low temp via precipitation reactions to a very high proportion of martensitic structure from their untreated predominantly austentitic state.

Maraging steels has been around for a very long time, mainly for used as armour plate, armour piercing projectiles and pressure resistant cases for solid fuel rockets. You can heat treat them to get hardnesses up to 60 Rockwell C, which is very, very hard, indeed. The most common chemistries resemble ultra low carbon austenitic stainless steel, but are lower in chromium, have more nickel and most either have very high Manganese or Cobalt content (usually >10 weight percent) and microalloying additions of Titanium and Molybdenum are common. They quench to a microstructure of primary martensite and some retained austenite with a rather low hardness that has good machinability and exhibits moderate transformation induced plasticity (TRIP), depending on the volume fraction of retained austenite. An aging heat treatment a phenomenal precipitation hardening response with very little volume change (and hence shape change or distortion). Ideal for things like gears and aluminium die casting tools.

[blkirk]

Originally posted by desmo
Silver plating Ti! Wow! I know that prolonged contact between Ti bits is an invitation to seizure and have heard the process described as cold welding. I suppose any plating would help there, but I didn't know silver plate was tough enough for gears.

In the oil industry, silver plating is used as a lubricant for down hole bearings and seals. It's the only material that can handle the loads and the highly corrosive environment. For offshore drilling, the seal between the wellhead on the ocean floor and the pipe back up to the rig is usually 316 SS and is disposable. The company I used to work for makes an alternate seal from 17-4 PH. It is silver plated and is reusable.

Silver works well for things like this because it is ductile and flows relatively easily. I'm surprised the gear makers managed to get the silver plating to stick to the Ti. But I'm not a metallurgist. Maybe the two of them bond quite easily.

[Top Fuel F1]

Originally posted by desmo


I knew I had heard the term maraging recently and it was in adverts for golf clubs, "metal woods"[oxymoron!]. Maraging steels are very low C which can be heat treated relatively quickly and at low temp via precipitation reactions to a very high proportion of martensitic structure from their untreated predominantly austentitic state. Pre-treatment they are very EDM-friendly, which is apparently how modern F1 gearsets are now machined. McLaren uses Chamilles Robofil 403051 EDMs to manufacture their gears in house capable of machining to a tolerance of 2 microns! It takes about 3 hours to machine a gear on the EDM. I've seen published yield strengths of 2000MPa (290Ksi) for maraging steels which is to me astonishing. These steels seem to have emerged from "under the sheet" and are widely available now, and indeed there seems to be a cadre of speculators that deal in these steels as investments now!

1. Maraging Steels: High strength low carbon iron nickel alloy in which a martensitic structure is formed on cooling; 6-7% nickel, 0-11% Cobalt, 0-5% molybdenum and small percentages of TI, AL and Columbium; hardening is done by heating the quenched alloy at 400-500 degrees C.

2. Martensitic Structure: Of pertaining to, or having the structure of martensite, that is, an interstitial, supersaturated solid solution of carbon in iron having a body-centered tetragonal lattice; the microstructure is characterized by an acircular or needle like pattern.

Rgds;