TiB2 coating

[jackson]

Has anyone tried this new coating for aluminum TiB2 Titanium diboride i just got some literature on from one of my tooling reps

Background

TiB2 is the most stable of several titanium-boron compounds. The material does not occur in nature but may be synthesised by carbothermal reduction of TiO2 and B2O3.

As with other largely covalent bonded materials, TiB2 is resistant to sintering and is usually densified by hot pressing or hot isostatic pressing. Pressureless sintering of TiB2 can achieve high densities but liquid forming sintering aids such as iron, chromium and carbon, are required.
Key Properties

Table 1. Typical Physical and mechanical properties of titanium diboride.

Property




Density (g.cm-3)


4.52

Melting Point (°C)


2970

Modulus of Rupture (MPa)


410-448

Hardness (Knoop)


1800

Elastic modulus (GPa)


510 -575

Poisson's Ratio


0.1 - 0.15

Volume resistivity (ohm.cm) at 20°C


15x10-6

Thermal conductivity (W/m.K)


25

TiB2 is resistant to oxidation in air up to 1000°C. It is also resistant to HCl and HF but reacts with H2SO4 and HNO3. It is readily attacked by alkalis.

Hot pressing of TiB2 (with small additions of metallic or carbide sintering aids) is carried out at 1800 - 1900°C and achieves close to theoretical density. Pressureless sintering requires higher levels of sintering aids and sintering temperatures in excess of 2000°C.
Applications

Due to its high hardness, extreme melting point and chemical inertness, TiB2 is a candidate for a number of applications.
Ballistic Armour

The combination of high hardness and moderate strength make it attractive for ballistic armour, but its relatively high density and difficulty in forming shaped components make it less attractive for this purpose than some other ceramics.
Aluminium Smelting

The chemical inertness and good electrical conductivity of TiB2 have led to its use as cathodes in Hall-Heroult cells for primary aluminium smelting. It also finds use as crucibles for handling molten metals and as metal evaporation boats.
Other Applications

High hardness, moderate strength and good wear resistance make titanium diboride a candidate for use in seals, wear parts and, in composites with other materials and cutting tools.

In combination with other primarily oxide ceramics, TiB2 is used to constitute composite materials in which the presence of the material serves to increase strength and fracture toughness of the matrix.

i drill alot of alum. so any feed back on this would be great

Thanks

[Gumby]

You aren't clear. Do you want this for applying a coat to aluminum or it is for a cutter that to cut aluminum.

One question I would ask your rep is how are they apply the TiB2 (electroplating or vapor deposit).

[fpworks]

Gumby,
He's talking about TiB2 coated tools.

jackson,
I have a TiB2 coated sample from Garr here...haven't tried it yet. I've had reasonable success with ZrN coated tools and the greatest success with TiCN coated tools. I've "heard" that TiB2 is harder than TiCN...not sure if there is any truth to that, but if so, it should be spectacular. My TiCN coated tools simply don't wear in aluminum. It doesn't make sense to me...I have maybe 3000 lbs of aluminum through a 0.5" SGS TiCN endmill, and it still cuts and finishes like it is brand new.

If you try one out, please keep us posted...I've heard very little real world experience about this coating.

[kalmah]

TiB2 coating improve the tool life in aluminium and titanium (only in finishing).
Ask CEMECON USA for further information.