Refinement of Master Densification Curves for Sintering of Titanium

Abstract

An approximate master curve for the densification of cold-pressed titanium powder during vacuum sintering was published previously. It was based on the combined results for three different titanium powders. The master densification curve model incorporates the effects of particle size, compaction pressure, sintering time, and sintering temperature on densification. The collection of a large amount of additional data now allows refinement of the model. Distinct curves are presented for three different titanium powders, prealloyed Ti6Al4V, and Ti-Ni binary alloys. The master densification curve is sigmoidal, but deviates from the ideal form at high sintered density; the relative sintered density saturates at 90 to 100 pct, depending on the particle size of the titanium powder, and to a lesser extent the compaction pressure. The master densification curve below the saturation level is slightly dependent on the compaction pressure.

Design of titanium alloy for efficient sintering to low porosity

“…In earlier work, the authors showed the effect of 5% additions of 45-63 mm Co, Ni, Fe, Cr, Cu, Mn, Mo, Sn and Si powders to Sumitomo 45-63 mm Ti powder on green and sintered density. 22 Those results and additional data obtained for the same Ti base powder, total alloying addition and compaction and sintering conditions are shown in Fig. 2.…”

“…8,[19][20][21] Later work showed that when the particle size of the alloying elements is the same as that of the titanium powder, the densification of binary alloys is roughly correlated with the diffusivity of the element in titanium. 22 High density (y99%) has been reached for additions of up to 10% of the fast diffusing elements Fe, Co and Ni. 8,11,12,14,23 The literature on sintering Ti alloys is dominated by the traditional wrought alloy Ti-6Al-4V.…”

Analysis of the effect of solubility on the densification behavior of tungsten heavy alloys using the master sintering curve approach

“…Blaine et al [12,13] used MSC concepts to determine apparent activation energies for densification of several powder metal systems, including steels, tungsten heavy alloys, molybdenum, niobium, and nickel and compared them with activation energies for various diffusion mechanisms. Similar methodology was used by Robertson and Schaffer [14,15] to analyze the densification behavior of titanium.…”