Processing and Properties of Ni-Based Bulk Metallic Glass via Spark Plasma Sintering of Pulverized Amorphous Ribbons

Abstract

Ni-based bulk metallic glasses and composites with high absolute densities exceeding 11 g/cm3 were synthesized via spark plasma sintering of Ni45Co10Ta25Nb20 powders produced from pulverized, melt-spun amorphous ribbons. Optimizing the synthesis via selection of sintering temperature, uniaxial load pressure, and powder mechanical screening yielded samples with relative densities of nearly 100% and hardness values in excess of 12.5 GPa without cracking. Mechanical testing included Weibull modulus determination for hardness and compression testing at 10-3 s-1 and 103 s-1 strain rates. The capability of using spark plasma sintering to fabricate high hardness, high density, large scale metallic glasses is demonstrated. The mechanical properties of these compacted comminuted melt-spun glass ribbons are presented.

Fabrication of Titanium-Niobium-Zirconium-Tantalium Alloy (TNZT) Bioimplant Components with Controllable Porosity by Spark Plasma Sintering

“…The creep activation energy in all the cases analyzed is in good agreement with the value of the creep activation energy for β-Ti present in the literature (153 KJ/mol) [ 31 ]. Also, since TNZT is a β alloy, these values of activation energy can be correlated with the DSC curves where any endothermic peak due to the β-transition is not present.…”

“…In the present study, these relationships are investigated specifically for TNZT samples produced using SPS. After consulting the literature, the following trends were anticipated: Increasing the sintering temperature should increase the final sample density [ 29 ]; Increasing the sintering pressure should increase the final sample density [ 29 ]; Increasing the holding time should increase the final sample density [ 32 ]; Decreasing the initial particle size should increase the final sample density [ 33 ]; Using designed particle distributions can be employed to tune the compaction density [ 31 ]. …”

“…The values of the creep activation energy Q have been estimated using a regression analysis to obtain the best fit to the experimental data. The strain rate sensitivity value m was chosen based on the experimental data known in the literature for Ti ( m = 0.23) [ 31 ].…”

“…SPS has been shown to achieve faster densification than traditional sintering techniques [ 28 , 29 , 30 , 31 , 32 ]. Therefore, by creating porous components using SPS, a maximum amount of time saving can be achieved.…”

Crystallization Kinetics and Consolidation of Al82La10Fe4Ni4 Glassy Alloy Powder by Spark Plasma Sintering

“…Additionally, confirming this last statement is the appearance of a second broad peak on the righter side of the first peak at about 60 • and the sudden increase the relative density of the sample sintered at 623 K as shown in Figure 8b, which is the highest at about 97.2%. This relative density value is lower than that of Petersen et al for amorphous Ni-based alloy (> 99%) due to using the high pressure of 1 GPa and sintering after the first crystallization peak of 948 K together with screened ball-milled powder volume fractions of 60% with diameters 53 ÷ 106 µm and 40% with diameters <53 µm [42]. Figure 9 presents the results of density and micro-hardness measurements for the bulk amorphous Al 82 La 10 Fe 4 Ni 4 samples at various sintering temperatures.…”