Texture and Differential Stress Development in W/Ni-Co Composite after Rotary Swaging

Abstract

Knowledge of texture and residual stresses in tungsten heavy pseudoalloys is substantial for the microstructure optimization. These characteristics were determined in cold and warm rotary swaged W/NiCo composite with help of neutron diffraction. The results were discussed in view of the observed microstructure and mechanical properties. The investigated bars consisted of tungsten agglomerates (bcc lattice) surrounded by NiCo-based matrix (fcc lattice). No preferential crystallographic orientation was found in the as-sintered bar. A strong texture was formed in both the tungsten agglomerates (<101> fiber texture parallel to the swaging axis) and in the NiCo-based matrix (<111> fiber texture) after rotary swaging. Although usually of double-fiber texture, the <001> fiber of the fcc structures was nearly missing in the matrix. Further, the cold-swaged bar exhibited substantially stronger texture for both phases which corresponds to the higher measured ultimate tensile strength. The residual stress differences were employed for characterization of the stress state of the bars. The largest residual stress difference (≈400 MPa) was found at the center of the bar deformed at room temperature. The hoop stresses were non-symmetrical with respect to the swaging axis, which was likely caused by the elliptical cross section of the as-sintered bar.

Microstrain and texture in rotary swaged W–Ni–Co pseudoalloy

“…During rotary swaging, the large grains of Ni-Co are fractioned to fine-grained microstructure. A strong texture formed in both phases after rotary swaging [4]. Both bcc phase and fcc phase, after rotary swaging, have the same texture type as for wire drawing.…”

“…The textures for cold and hot swaging are qualitatively the same, but stronger for cold swaging which indicates that secondary deformation mechanisms are also active for the hot swaging. The deformation was also connected with formation of residual macrostresses [4,5].…”

Progress in partially degradable titanium-magnesium composites used as biomedical implants

“…Hot rotary swaging is an incremental shaping process, which is commonly used to modify the cross-sections of rotationally symmetric metal objects such as rods, tubes, and wires, as well as to link various materials or components. The hot rotary swaging procedure reduces grain-size in metallic materials, and effectively improves the mechanical properties of the material, and hot rotary swaging has been used for various demanding materials and alloys ( Chi et al, 2019 ; Kunčická et al, 2020 ; Strunz et al, 2020 ). The schematic diagram of preparing titanium-magnesium composites by hot rotary swaging is shown in Figure 4 .…”

Influence of High Pressure Sliding and Rotary Swaging on Creep Behavior of P92 Steel at 500 °C

“…Further details regarding the SPD techniques used in this investigation are given elsewhere [21][22][23][24]. Both the rod for RS and sheets for HPS were manufactured in the direction parallel to the longitudinal axis of the pipe.…”