Effect of melt hydrogenation on microstructure evolution and tensile properties of (TiB + TiC)/Ti-6Al-4V composites

Efficient Coarse‐Grained Superplasticity of a Gigapascal Lightweight Refractory Medium Entropy Alloy

“… Superplastic behaviors of the HC‐LRMEA samples. a) engineering stress‐strain curves obtained under tensile loading at temperatures of 973, 1073, and 1173 K and strain rates of 10 −3 and 10 −2 s −1 ; b) images of representative specimens fractured under temperatures of 973, 1073, and 1173 K and a strain rate of 10 −2 s −1 ; c) stress–strain, σ–ε , curves and strain‐rate sensitivity ( m ) values obtained from strain‐rate jump tests conducted at 1173 K with 4 different strain rates of 5 × 10 −4 , 1 × 10 −3 , 5 × 10 −3 , and 1 × 10 −2 s −1 , where n = 1/ m is the stress exponent; d) the hardness distribution of the sample after coarse‐grained superplastic deformation; the inset in (d) illustrates the hardness test and morphology of hardness indentation; e) yield strength versus superplastic elongation at high strain rates (10 −2 s −1 ) of coarse‐grained superplastic magnesium alloys, [ 25 , 26 , 58 , 59 , 60 , 61 , 62 ] coarse‐grained superplastic aluminum alloys, [ 28 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 ] coarse‐grained niobium alloy, [ 73 ] coarse‐grained superplastic intermetallics, [ 74 , 75 , 76 ] and coarse‐grained superplastic titanium alloys. [ 9 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 ] …”

“…By converting this hardness to the strength, a formula of HV ≈3 σ y [ 55 ] is used to characterize the strength, which indicates that the strength of HC‐LRMEA is still higher than 1 GPa after superplastic deformation (Figure 2d ). In addition, HC‐LRMEA is compared with other coarse‐grained superplastic alloys, including coarse‐grained superplastic magnesium alloys, [ 26 , 27 , 56 , 57 , 58 , 59 , 60 ] coarse‐grained superplastic aluminum alloys, [ 29 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 ] coarse‐grained niobium alloy, [ 71 ] coarse‐grained superplastic intermetallics, [ 72 , 73 , 74 ] and coarse‐grained superplastic titanium alloys, [ 9 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 ] Superplastic elongation at high strain rates (≥10 −2 s −1 ) versus strength is plotted in Figure 2e . The strength values of the coarse‐grained superplastic magnesium and aluminum alloys are relatively low, making them difficult to use in some high‐strength conditions.…”

“…Based on the measured elongation at fracture, the fractured specimens presented in Figure 2b show representative elongation values of ≈113% at 973 K (0.45T m ), ≈300% at 1073 K (0.5T m ), and ≈442% at 1173 K (0.55T m ). The results indicate that the total elongation of the specimen loaded at 0.45T m exhibited no obvious superplasticity, while the degree of elongation increased substantially with , where n = 1/m is the stress exponent; d) the hardness distribution of the sample after coarse-grained superplastic deformation; the inset in (d) illustrates the hardness test and morphology of hardness indentation; e) yield strength versus superplastic elongation at high strain rates (10 −2 s −1 ) of coarse-grained superplastic magnesium alloys, [25,26,[58][59][60][61][62] coarse-grained superplastic aluminum alloys, [28,[63][64][65][66][67][68][69][70][71][72] coarse-grained niobium alloy, [73] coarse-grained superplastic intermetallics, [74][75][76] and coarse-grained superplastic titanium alloys. [9,[77][78][79][80][81][82][83][84] increasing temperature to 0.5T m , and apparent superplasticity is observed at 0.55T m .…”

Effects of Melt Hydrogenation on the Microstructure Evolution and Hot Deformation Behavior of TiBw/Ti-6Al-4V Composites

“…To overcome these shortcomings, we added hydrogen to the metallurgical process, which involved smelting raw materials under an atmosphere of hydrogen/argon mixture, termed Melt Hydrogenation Technology (MHT) [ 29 ]. MHT can simultaneously complete the synthesis and hydrogenation of titanium-based materials, including titanium alloys [ 30 , 31 ], γ-TiAl alloys [ 32 , 33 ], and TMCs [ 34 , 35 , 36 , 37 ]. In the literature [ 34 ], the hot workability of (TiB + TiC)/Ti-6Al-4V composite prepared by MHT was investigated; it was found that hydrogen induced the competing of softening and hardening in the hydrogenated TMCs at different deformation temperatures and that MHT improved the motion coordination between the reinforcements and matrix during hot compression.…”

Microstructure Evolution and Enhanced Hot Workability of TiC/Ti-6Al-4V Composites Fabricated by Melt Hydrogenation

“…Based on traditional hydrogenation, this study presents a more advanced melt hydrogenation technology [10,11], which involves melting the materials directly within a mixed atmosphere of hydrogen and argon. Wang et al [12] reported that melt hydrogenation could allow TMCs to be deformed at lower temperatures and higher strain rates. Lin et al [13], meanwhile, reported that melt hydrogenation decreased the peak flowing stress of TMCs from 240 MPa to 199 MPa at 850 • C/0.01 s −1 .…”