Ducati front axle question, is sort of Laverda related

[laverdakeith]

My SFC eletronica had berillium copper valve seats, look like they were put in by the factory does cut lovely but is a bit poisonous, don't think that was such an issue in the pre health and safety 1970's.

  Keith

 

[breganzane]

Used to use a bit of BeCu at work, still have some though not much call for it.  Is great for making custom shim springs since it hardens nicely in boiling oil to make great spring clips etc.  Isn't it still used for valve seats?  Works well with Ti valves, or maybe that's some other copper alloy.
The Be F1 components I heard about were pistons etc and they were lighter after a few laps in 1500hp 1.5lt turbo cars in practice.  The missing material was presumably going out the zorst and they decided that might be a bad idea.

 

[mcnicol]

Interesting correlation Steve, but beryllium is way off the trend line. According to Wikipedia, it has specific gravity of 1.85 and Youngs modulus of 287 GPa. That makes it lighter than aluminium and stiffer than steel. Maybe we should be making axles out of beryllium alloy.

US Navy used to use it for tubular struts on undercarriage of naval fighter jets, had to absorb enormous stresses on landing. But berylliium can't be drawn into tubes, they had to form tubes from flat sheets and weld them up.
Funny how now the Russians are friends of the US the stresses on naval fighter undercarriages have got less and chrome-moly steel can do the job adequately. Not saying that military contracts sometimes have an under-the-table hidden side, that just wouldn't be right... :

Ken

 

[sfcpiet]

My SFC eletronica had berillium copper valve seats, look like they were put in by the factory does cut lovely but is a bit poisonous, don't think that was such an issue in the pre health and safety 1970's.

  Keith

Indeed OE in the all-alloy 750SFC heads.  Still got a couple, will find a use for them someday!

piet

 

[Basketcase]

Interesting.

I thought valve seats were aluminium bronze. At least they were in the days before leaded fuel. Had them in my old 1950's alloy head Ariel Square Four and even my 1960s Matchless competition heads. Tetraethyl lead attacked the exhaust seats.

Beryllium bronze gives enormous forging strength and was used for tools on oil rigs.

Copper beryllium is good for springs.

The biggest concern is that titanium does not have an endurance limit as far as I am aware. OK for race bikes rebuilt with new components on a regular basis.

At least steel stressed below its endurance limit will last an infinite number of cycles.