Microstructure, Tensile Flow and Work Hardening Behavior of W–Ni–Fe Alloys: Effect of Co and Co + Mo Additions

Effects of Co and Co + Mo additions on tensile properties of tungsten heavy alloys: first-principles study and experimental investigations

“…This clearly reflects that the addition of W in the matrix phase not only increases the strength values but also shifts flow behaviour towards higher strength as a function of strain. The yield strength values of the systems are very close to σ YS of the experimental alloys (Table 7) [20]. It is to be noted here that the compositions of the matrix phase of systems and alloys are nearly the same while the overall compositions of the alloys and systems are quite different, particularly in terms of bulk W contents (Tables 1 and 4).…”

“…Stress-strain curves generated (up to 20% strain) using the Nielsen-Martin Scheme for the systems 82-S, 82C-S and 82CM-S are shown in Figure 4. The experimental engineering stress-strain curves of the alloys 82, 82C and 82CM are also included in Figure 4 [20]. The experimental values of σ YS , strength at 20% strain, σ UTS and % elongation are given in Table 7 [20].…”

“…The Nielsen-Martin Scheme has been employed to generate stress-strain curves (up to 20% strain) for the systems 82-S, 82C-S and 82CM-S (Figure 4) [29,30]. The engineering stress-strain data of the alloys 82, 82C and 82CM [20] are also included in Figure 4. The corresponding values of yield strength and strength at 20.0% strain of the systems 82-S, 82C-S and 82CM-S are given in Table 7.…”

“…The proposed supercell consists of W-grain and matrix phase along with 72 atoms (W-grains: 24 and matrix phase: 48) and two bcc–fcc interfaces. These results are compared with the experimental data of the W–Ni–Fe, W–Ni–Fe–Co and W–Ni–Fe–Co–Mo alloys published elsewhere [20]. The compositions of the matrix phase of alloys determined experimentally are utilised for the first-principles calculation.…”

Ultrafine-Grained Tungsten Heavy Alloy Prepared by High-Pressure Spark Plasma Sintering

“…However, it is still a challenge to fabricate high relative density and fine grain bulks, which are expected to show an enhanced performance. Appropriate additives, such as Cr, Co, Mn, Re, Al, Si, Sn, Zn, YSZ, and Y 2 O 3 , were suggested to refine the microstructure of tungsten alloys [ 8 , 25 , 26 , 27 , 28 , 29 , 30 ]. The alloys could also be enhanced by cold plastic deformation after annealing at lower temperatures [ 31 ].…”