Titanium – The heaviest light metal

Titan das schwerste Leichtmetall© Fronius

Titanium – The heaviest light metal

Dan Snitkovsky

Uniweld Israel

FRONIUS International GmbH

Buxbaumstr. 2

4600 Wels

© Fronius Titan das schwerste Leichtmetall

Titanium – The heaviest light metal

Lithium -

light metal5g/cm³

0,5g/cm³ 4,5g/cm³ Heavy metal

Titanium


TITANIUM,

Part of the IVb group of the table of the elements

(titanium, zirconium, hafnium)

Vb group

(Vanadium, niobium, tantalum )


Titanium

Part of the IVb group of the tableof the elements (titanium, zirconium, hafnium)

Vb group(vanadium, niobium, tantalum )


Advantages

Highest corrosion resistance Good oxidation resistance at < 600°C Low density High specific strength Excellent yield strength Outstanding biocompatibility Excellent decoration ability


Turbine engine construction


Application turbine


Implant in the dentistry


Implant, turbo charger, turbine industry


Lynx helicopter rotor


Defense industry


Attention:

At more than 9% aluminium dangerous brittle intermetallic phases can be developed

This is the reason that titanium is only available with max. 8% Al.


Attention:

Not more than 0,1% O2 in titanium, otherwise:no corrosion resistance no weldabilityno more ductility


Attention:

No H2 – enemy no. 1 !!

Has to be less than 10-3 (0,001%) otherwise Embrittlement Drops out HYDRIDE PHASE

Solubility H2 at 300°C = 18 weight%

Solubility H2 at RT only = 0,002 weight%


Attention: No N2 !

Embrittlement starts at 0,3 weight%

Oxygen equivalent contamination in (weight%)

Q = (O2) + 2 (N2) + 2/3 (C)

Hardness (HB) depends on (O2) : HB = 40 + 310 Q


Tensile strength:

Unalloyed titanium has 290 up to 740N/mm²


Higher tensile strength is only achieved by alloying:

Ti6Al4V unalloyed titanium

other

alloys


( + ) = standard alloy since 1940 in USA

start of production for the first time in 1954 -

„Pratt+Whitney / General Electric“ at turbines

(3.7164) = Ti 6Al 4V has 900 bis 1300 N/mm²

90% 6% 4%

At 300°C long term performance is OK, but turbines have to

fulfill higher demands - more about that later


Selection of filler metal for welding

Because of ductility choose always one grade/step

„lower“ undermatched wire .

Anyway the seam will be 50HB harder than the

base material.

Reason: unintentional amalgamation with O2/N2


Brazing: Most frequently silver-basedShort dwell period required, otherwise phase-

formation, for this reason small parts only.Brazing with: Ti 15Ni 15Cu (953° – 970°C)

fair wetting behavior, but corrosion resistance is ok, furthermore the mechanical properties are better.

Ti 48Zr 4Be (898° – 926°C)good wetting behavior, but worse brazing results for the rest

As solder for titanium you may also use:Al 99,5 / AlMn / AlSi 12

Ca. 680° – 690°C

Electron beam welding

Vacuom 10(-4) Torr




Titanium WIG – special arrangements



Titanium WIG – special arrangements





Orbital welds




Titanium MIG – special arrangements


Titanium MIG – special arrangements

Teflon innerliner top wire feeding properties Non-sensitive to high

temperatures less abrasion in the innerliner

Teflon drive rolls - because titanium is

very soft and sensitive regarding feeding and

contamination


Titan das schwerste Leichtmetall© Fronius

RCU 5000i Remote Control Unit


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Titanium – The heaviest light metal