SKULL MELTING FURNACE FOR VACUUM MELTING OF TITANIUM (GR. 1 to 5), LIGHT ALLOYS AND SUPERALLOYS

The aim of the “Skull Melting” technology is the vacuum arc melting of titanium sponge and/or scrap (up 100% of scrap) and the direct casting of rounded ingots or rectangular slabs, these one ready to be rolled, thanks to their shape and quality.
The main features of the technology are:

1. The process foresees single-melted products (slab/ingot), thus highly reducing energy and labour consumption in comparison with the conventional reference technology (VAR) and other hi-tech technologies (like the EB).
2. The furnace can be fed with titanium all-scrap melting charges in every shape and size, without any cutting and pre-blending operation. Moreover, the use of even very large pieces reduces the oxygen contamination, really avoiding the addition of any gram of sponge.
3. An innovative control system for the solidification parameters allows the realization of semi-products whose shape and quality are suitable to simplify the subsequent transformation (i.e.: direct slab rolling).
4. The electrode regeneration capability makes the process completely autonomous and the Skull Melting furnace can be operated as a stand-alone plant, not to be incorporated into combined production cycles with other titanium production equipments.

The innovative technology is different from the conventional ones mainly for the set-up of a single big pot of a molten titanium, which is completely poured at one time in about 30 sec. into a special mould, where the solidification of the cast metal takes place in a short time.
Consequently the homogeneity of the slab is ensured as well as the quality of the slab, which is ready to be rolled after surface grinding or machining to obtain plates and sheets.

In the same way the furnace is capable to vacuum melt other light reactive metals, e.g. like Zirconium, light alloys or superalloys.
TECNOCENTRO eng. until today has supplied n. 3 units, the first producing since 2001 1.5 ton Titanium or Zirconium ingots and/or slabs, the second and the third, respectively  1.5 and 2.5, fully operating since middle of 2007.

Furnace plant casting capability                                                         up to 2000 tons/year
Slab/ingot max weight (as-cast)                                                         up to 3000 Kg/melting cycle
Melting phase duration                                                                        about 1 hour
Production cycle overall duration (including melting phase)       about 8 hours
Vacuum pressure                                                                                up to 0,1 Pa
Specific AC energy consumption (for Ti)                                          1.7 KWh/Kg (of as-cast slab/ingot)