Titanium has been all the rage with motorcycles and quads, why don't we see more of it in sailing other than some hardware? The carbon vs aluminum mast thing got me thinking of it. I'd think there'd be benifits to using it for anywhere we're currently using aluminum, or stainless steel. Except maybe the masts, I think its extremely stiff, but I don't know that for sure.

I bought a full titanium exhaust for a race quad once, almost $900, but I think the complete system weighed something along the lines of a couple of pounds including the silencer.

Simple answer: because the load cases are totally different. Motorcyle is a frame. Material is selected by strength to weight ratio, good for Titanium, CFRP, even some steel alloys (which are as expensisve than as Titanium...)
Sailing mast is a aeroshape, it is build for stiffness and buckling, hence the material must have good stiffness to weight properties. Hence it would be alu or better CFRP (sometimes wood would be even better; not for usual cat mast, however).

Cheers,

Klaus

I have in the past used titanium bolts which contact the carbon. Less electrostatic corrosion..
One could look at magnesium alloy masts I guess..

What about heavy and larger items like beams, or rudder stocks as well?

Again a beam is driven by stiffness, so better take alu or even better CFRP.
Rudderstock, hm never thought about it. The rudder head, where the rudder pivot is fixed, could be made of titanium space frame, the bolts and so on as well. But the weight saving is small.

Actually i don't know about motorcycles, but on bicycles, Titanium was more for fashion than weight/stiffness, at the end CFRP was lighter, but Titanium was rare, a statement of style like a exclusive watch, mystic soviet technology...

Titanium (22) is almost twice as heavy as Aluminum (13).. But it does have some properties that make it interesting but to go lighter than carbon you looking at lighter elements. Carbon is 6 so that means the elements lithium (3), Beryllium (4) and Boron (5)..

I'm not an structural engineer or materials scientist.
One could investigate a carbon/boron beam.. Increased modulus but like everything its a trade off.. As modulus goes up so does cost and so does its brittleness.. So its benefit may not be great even in a fully "open" class. You would just have to add more lead in the F16!!

magnesium aluminum alloy beams I suspect would be close to or above a carbon beam in cost and I shudder to think what a lithium-beryllium based alloy would set one back..

From its structural properties a magnesium beam would be quite good, however magnesium is very sensitive to corrosion, especially in salty environment.
In theory beryllium has excellent properties, but it is difficult to handle, it may burn, when milled and it is higly toxic.
In aviation the most promissing metallic material is alumium-lithium alloy, because of its low density, and the hybrid alumium glass fibre (fibre metal laminate). However environment and load cases are different to what we see on beach cats.

At the end of the day you need only focus on alu, glass, carbon and wood as materials for small cats, without missing any significant benefit. You can improve the design much more by good engineering, rather by material choice (e.g. not a constant layer setup for the whole hull). You can have a huge benefit by swithching from polyester to epoxy. However exotic materials are good for marketing.

The areas where I think titanium should be seriously considered are the places where stainless steel is currently used. The most common is the rudder system. If titanium gudgeons and rudder stocks were available, many people would switch to avoid failures in these areas. Of course, you may rip the entire transom off instead of breaking a $15 gudgeon or pintail, but that is a risk some are willing to take...

I have one data point for Ti, which does not bend much before it breaks, on boats...

The big boat I race on had titanium stantions for the lifelines. While racing at Block Island one year, we launched off a wave and the crew hit hard against the lifelines. Two stantions snapped, and one bent.

We no longer have Ti on the boat.

Some materials just don't work in some situations. And I am a huge fan of Ti for bikes, rides like steel but light like Aluminum.