Cost of Titanium

Can someone tell me why Titanium is so expensive? It is a very common ore
we now know. Is it the refining process? I read the Navy has a ship made of titanium and aluminum. Would that have a dissimilar material corrosion problem? It seems to me that it is a perfect material for boats. PS does it weld easy?

 

Steel is extacted using a blast furnace which is quick and relatively cheap. however to extract titanium, magnesium is needed because it is more reactive. magnesium is extracted by electrolysis, which is expensive therefore it is not cheap to buy. you have to buy the magnesium to extract the titanium, which is why titanium is expensive.
Titanium Manufacturing Process
https://www.youtube.com/watch?v=gXuU-Na0gLQ

 

Titanium is very easy to weld.
If you are using the best grades the welding will reduce the properties in the weld joint.
But boats will probably never use that level of material. (somebody will prove me wrong just for fun).
We put Ti and Aluminum together in bolted joints all over an aircraft. But both parts are painted and sealed. It is usually not considered dissimilar since it is not much of a problem.
Ti is a favorite were corrosion is a problem, especially in Navy aircraft. It just cost so much and is tough to machine and drill.

I usually expect Ti parts to be 4 to 6 times the cost of the same aluminum part.
Ti is about 60% higher density, but stronger.

To use the ti to its best advantage you need a strong engineering/ analysis background.

 

This picture is titanium plate I carefully selected to EDM wire cut and CNC for one of my multi-tool key ring designs pictured below.

When I cut from plate I leave the raw surface plate finish to see the grains of the metal as in a work of art.

To polish titanium it is easy to scratch, and when its shot blast, it looks like lost wax cast and not machined from plate.

Its not so much the cost of the raw plate to further manufacture, its the machining cost or if cast it has a expensive vacuumed process and are not normally made in large amounts to keep the cost down.
For example the factory I buy my titanium from also manufacture vacuumed lost wax investment casting about one time ever two weeks to accumulate the amount of product to make it financially viable

 

The University of New Orleans School of Naval Architecture just completed a multi-year study of shipbuilding in Titanium. You might contact Larry DeCan there for more information.

But as I recall, one of the big cost drivers in commercial Titanium pricing is that the metal quality and finish is being determined by aerospace specifications. Marine and industrial applications can accept much less expensive manufacturing processes. (It had something to do with the number of times the metal is melted, purified, and re-formed if I recall correctly.) But such "industrial grade" Titanium is not in demand, therefore production is small, therefore the price is driven back up by small batch sizes.

But again: Go ask Larry, he's got lots of data on the real prices.

Chris

 

This is another example of some marine tools I designed and manufactured from plate with EDM wire cutter and carefully ground the edges which was a good learning how much titanium cost to manufacture and most of all the mechanical properties expectations.

 

Titanium is not easy to weld. At temps above 800, without proper shielding the weld can easily become brittle from hydrogen, oxygen or nitrogen, (air and water vapor)
For a good weld you need the root surrounded by an inert gas. When welding pipes, usually you have to fill the pipe with argon to ensure a good weld

 

Ti takes a lot of energy and specialize process to make.

it does suffer dissimilar metal issues, but usally assembly is with sealants as well as painted surfaces.

Ti, though corrosion resistant, is highly reactive to common materials, salts, cad plated fasteners, etc. You get inter-granular corrosion tracks at the microscopic level, which is usually discovered after the part suddenly fails without warning (usually catastrophically). Bolt heads just pop off suddenly, cast fittings pop apart while sitting on a shelf, no loads on it at all.

When I once worked for the little local aircraft manufacturer over twenty years ago, I had to write a service bulletin to replace the large cad plated bolts holding the Ti alloy engine mounts to the underside of the wing. A number of commercial aircraft were delivered with cad plated bolts in the Ti fittings, they had to all be replaced (which means defueling the wings to get access to the bolt heads from inside the fuel tanks), removing the six 1" dia high strength bolts, removing the engine mounts fittings and sending them to a metallurgy lab to test the fittings for cadinum embrittlement of the alloy (there is no field test for that problem). If they had cad embrittlement present, the costly parts had to be scraped, there was no way of salvaging them. something like 22 aircraft were effected, four engines each aircraft, four fittings per engine, six bolts per fitting. It was a very costly assembly mistake. The company learned about the assembly error when an operator reported a failed engine mount, which occurred while the aircraft was parked, engine off (it just "popped" off while sitting still, engine hanging off at an odd angle held up by the wire bundles and the hydraulic lines). An investigation found that the painted bolts specified were not available during the production run and a supply agent substituted the cad plated bolts, which were structurally identical (and normally a good substitute), but a tiny foot note on the massive wing assembly drawing was overlooked that stated "no substitute", and no explanation as to why. They met their production dead line, but unwittingly created a very serious safety hazard in the process.

I am not sure how this kind of problem would play out in a boat subject to a rather harsh chemical environment and not nearly the kind of carefully supervised assembly and maintenance as compared to aircraft (where all the suppliers, mechanics, and supervisors, and inspectors, have to be certified for anything on a commercial aircraft).

some kind of industrial grade Ti might be a solution, if the intergranular corrosion and contamination issues can be worked out. but it might be that Ti of that quality may offer no advantages over much less costly and well known aluminum alloys for marine applications.

Titanium is not quite the "magic" material everyone thinks it is. Not just costly, but has some very practical limitations and down sides.

 

http://en.wikipedia.org/wiki/Airbus_A350_XWB

This is a fine example about quality uses of titanium and the long run savings of maintenance and fuel cost.

The A350 XWB will be made out of 53% composites, 19% Al/Al-Li, 14% titanium, 6% steel, and 8% miscellaneous.[102] This compares to the Boeing 787 Dreamliner, which consists of 50% composites, 20% aluminum, 15% titanium, 10% steel and 5% other. October 2008 was the Airbus internal goal to freeze the design and Airbus expects 10% lower airframe maintenance cost and 14% lower empty seat weight than competing aircraft.

 

what the company "expects" and what it gets are often far different than the reality. These kind of claims are often wishful thinking and usually released for marketing purposes to get that costly new deign sold before they even build any. I have been involved with this too many times to know not to trust such claims for something as complicated as an aircraft, particularly when using new technology, newly developed materials and new construction methods. IOW, do not always believe what you read.

For example, how do they expect a whopping 14 percent lower empty weight for similar aircraft when the Boeing product has almost identical material utilization? Nowhere in the history of aircraft have they ever achieved an overall 14 percent lowering of empty weight with a single new design. Sounds like marketing BS to me.

I will believe it when I see it.

 

http://www.businessinsider.com.au/titanium-airplane-seat-weighs-under-9-pounds-2014-12

Benjamin Saada, Jean-Charles Samuelian, and Vincent Tejedor created Expliseat in 2011 and have now started selling it. Made from titanium and composites, it weighs just 4 kg (8.8 lbs).

The Recaro seats used by United weigh 11 kg.

The difference is enough to cut fuel consumption to the tune of up to $US400,000 per plane per year, the company says. If that’s right, putting these seats on all 300 of Ryanair’s 737-800 jets could save the budget airline about $US120 million a year.

The seat, which consists of just 30 parts and is “pre-reclined” by 18 degrees, is designed for use in the Boeing 737 and Airbus A320 family of aircraft. Those are the most popular planes for short- and medium-haul flights and represent a huge market
potential

Aircraft manufacturers and airlines are constantly striving for ways to save fuel by cutting down on weight with no airworthiness degradation. The rule of thumb is that cutting weight by 1% can save up to 1.5% in fuel.


An estimated 59 metric tons (130,000 pounds) are used in the Boeing 777, 45 in the Boeing 747, 18 in the Boeing 737, 32 in the Airbus A340, 18 in the Airbus A330, and 12 in the Airbus A320. The Airbus A380 may use 77 metric tons, including about 11 tons in the engines. In engine applications, titanium is used for rotors, compressor blades, hydraulic system components, and nacelles. The titanium 6AL-4V alloy accounts for almost 50% of all alloys used in aircraft applications.

 

That is a very old quote about the Airbus, can you find the actuals now?

I've seen a corporate president praising a material I was evaluating which had never completed material testing.
Myself, I would be a little suspicious about the claimed savings.

I wonder if Airbus knows about the Al-Li cracking issues? It has been used in multiple aircraft in very specific applications, lately after some expensive testing.

I will believe it when I see it, also.

 

A "pre-reclined" seat means they dropped the weight by eliminating the mechanism.
None of us can tell what portion of the weight that says, but you really shouldn't swallow the advertising line completely.
Making the seat back thinner will also reduce the weight, I would guess.

Don't make claims for one material based on a complete redesign.

Has anyone sat in one of these seats? Looks very uncomfortable to me.

 

An estimated 59 metric tons (130,000 pounds) are used in the Boeing 777, 45 in the Boeing 747, 18 in the Boeing 737, 32 in the Airbus A340, 18 in the Airbus A330, and 12 in the Airbus A320. The Airbus A380 may use 77 metric tons, including about 11 tons in the engines. In engine applications, titanium is used for rotors, compressor blades, hydraulic system components, and nacelles. The titanium 6AL-4V alloy accounts for almost 50% of all alloys used in aircraft applications.

 

You have no idea do you. Just posting articles off other sites.