Effect of powder state on spark plasma sintering of TiAl alloys

Densification and microstructural evolution of a high niobium containing TiAl alloy consolidated by spark plasma sintering

“…4). The yield stress would be decreased with temperature increasing [21]. Meanwhile, joule heat was generated at the contact zones and high temperature plasma was generated in the gap between powder particles, due to electric discharge at the beginning of ONeOFF DC pulse current [10,24].…”

Sintering Behavior of Lanthana‐Bearing Nanostructured Ferritic Steel Consolidated via Spark Plasma Sintering

“…The temperature at which densification begins (T s ) and the temperature at which maximum densification rate occurs (T max ) can be calculated from the displacement curve and its first derivative, respectively. [20,21] The T s and T max values were calculated, their variation as a function of milling time is shown in Figure 1b. Figure 1a shows the differences between the profile of the unmilled powder and milled powder; the displacement profile of the unmilled powder had a large displacement before the sintering began, and this behavior was not observed for any of the milled powders.…”

“…[2] The NFSs also have a high dimensional stability under irradiation, i.e., high resistance to swelling and irradiation creep. [3] The NFSs are typically processed via mechanical alloying (MA) of the powder mixture of Fe- (12)(13)(14)(15)(16)(17)(18)(19)(20) Cr-Ti-W/Mo (rapidly solidified prealloyed or blended elemental powder) followed by a hot consolidation route such as hot isostatic pressing (HIP) or hot extrusion. [3] The most widely used oxide constituent for NFSs is yttria (Y 2 O 3 ).…”

Microstructural Development and Mechanical Properties of PM Ti–45Al–2Nb–2Mn–0.8 vol.%TiB2 Processed by Field Assisted Hot Pressing

“…It seems that once the metastable powder is heated to temperatures above 800 ºC, stable phase appears and rising the temperatures leads to the stabilization of  2 + phases, according to the equilibrium phase diagram 26, 33,44,45] . However, as Figure 4 shows, heating the metastable powder to 800 ºC in the DTA and cooling, is not enough to form lamellar structures consisting of  2 + phases.…”

“…It has been found that the effect of the current is the fast generation of internal heat by Joule effect which increases the sintering kinetics [25,26] , providing a rapid densification of powders and minimal grain growth. Extensive research is currently going on to process various compositions, to understand microstructure evolution, mechanical properties and upscaling to produce actual components by using field activated sintering techniques [14,19,[27][28][29][30][31][32][33][34][35][36] .…”