Low-cost titanium hydride powder metallurgy

Powder metallurgy of titanium – past, present, and future

“…The sintering profile used to produce Ti-6Al-4V from hydrogenated powder in these studies utilised times and temperatures similar to sintering metallic powder (1200-1350°C for 4 h) [195,201]. Therefore, as expected, this sintering process produces Ti-6Al-4V with a lamellar structure, very similar to that achieved via a typical press and sinter process of Ti blended with elemental or master-alloy powders.…”

“…Therefore, as expected, this sintering process produces Ti-6Al-4V with a lamellar structure, very similar to that achieved via a typical press and sinter process of Ti blended with elemental or master-alloy powders. Figure 20 is a micrograph showing the as-sintered microstructure of Ti-6Al-4V produced by vacuum sintering Ti hydride powder blended with 60Al/40V master-alloy [201]. This microstructure consists of α colonies in the order of 100 μm across with individual lamellae in the order of 10 μm wide and 100 μm long.…”

“…As would be expected and as shown in Figure 30(c), this translates to improved tensile properties as well. Vacuum sintering of BE powders using TiH 2 has reported tensile strengths as high as 1050 MPa or ductility as high as 17%EL for lower strength samples [201,202,341,357]. It has been suggested that by optimising the variables, such as initial powder size, compaction pressure, and sintering temperature and time, the tensile properties can be further improved for vacuum sintering of PM Ti-6Al-4V produced using BE TiH 2 powders [340].…”

Oxidation and Corrosion Behavior of New Low-Cost Ti-7Fe-3Al and Ti-7Fe-5Cr Alloys from Titanium Hydride Powders

“…Fe powders has D 50 of 34 µm and the Al powders has D 50 of 130 µm, being the biggest particle size of all powders added to produce the Ti alloys. The advantages of the introduction of titanium hydride powder as starting powders are lower cost, higher compressibility, and better oxygen control [23,24]. However, the dehydrogenation process may be affected by factors like the atmosphere employed during heating, presence of impurities or the formation of intermetallics.…”

“…Ivasishin et al [23] also described how single-phase TiH 2 (δ) exists up to 450 • C where it begins to decompose and (TiH 2 (δ) → β) phase transformation occurs. Then, (β → α) transformation takes place where, at approximately 650 • C, and only single α phase is left; eventually at higher temperatures α phase transforms into the β cubic phase.…”