Effect of alloying addition and microstructural parameters on mechanical properties of 93% tungsten heavy alloys

Kiran, U. Ravi; Panchal, Ashutosh; Sankaranarayana, M.; Rao, G. Appa; Nandy, T.K.

doi:10.1016/j.msea.2015.05.046

Cited by 88 publications

(14 citation statements)

References 11 publications

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“…% to improve the strength, however, the strength usually increases at the expense of ductility; the content of matrix-forming elements lower than 3 wt. % usually supports brittleness of the final product [21]. On the other hand, increasing the addition of alloying, i.e., matrix-forming, elements generally decrease strength, but increase ductility [22]; high contents of matrix-forming elements contribute to uneven shape of the cross-section of the sintered piece due to gravity sedimentation during sintering, and consequently to non-uniformity of mechanical properties.…”

Section: Introductionmentioning

confidence: 99%

Effects of Sintering Conditions on Structures and Properties of Sintered Tungsten Heavy Alloy

2020

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Probably the most advantageous fabrication technology of tungsten heavy alloys enabling the achievement of required performance combines methods of powder metallurgy and processing by intensive plastic deformation. Since the selected processing conditions applied for each individual processing step affect the final structures and properties of the alloys, their optimization is of the utmost importance. This study deals with thorough investigations of the effects of sintering temperature, sintering time, and subsequent quenching in water on the structures and mechanical properties of a 93W6Ni1Co tungsten heavy alloy. The results showed that sintering at temperatures of or above 1525 °C leads to formation of structures featuring W agglomerates surrounded by the NiCo matrix. The sintering time has non-negligible effects on the microhardness of the sintered samples as it affects the diffusion and structure softening phenomena. Implementation of quenching to the processing technology results in excellent plasticity of the green sintered and quenched pieces of almost 20%, while maintaining the strength of more than 1000 MPa.

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Section: Introductionmentioning

confidence: 99%

Effects of Sintering Conditions on Structures and Properties of Sintered Tungsten Heavy Alloy

2020

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“…Due to the substantial difference between the melting temperatures of tungsten and matrix-forming elements, THAs can hardly be cast and thus the typical fabrication technology of THAs combines methods of powder metallurgy (fabrication of powders-preferably by mechanical alloying, subsequent sintering, and possible final quenching), and processing via plastic deformation under hot or cold conditions [4]. Since the final performance and properties of the product can significantly be influenced by the selected processing steps, it is advantageous to optimize the used technology with help of characterization of the structural and microstructural phenomena (such as possible presence of residual stress and texture) and their effects on the final properties for each THA chemical composition and intended final product application [5,6].…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2020

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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.

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“…Alloying elements in THA ensure the plasticity of the material, a negative effect is a reduction in strength. For optimal strength and plastic properties, we can use a change in chemical composition or improvement of properties through plastic deformation [5][6][7][8][9]. Suitable technologies are processes that are continuous, such as ECAP-conform [10] or rotary swaging (RS).…”

Section: Introductionmentioning

confidence: 99%

Experimental Verification of Mechanical Properties of Thungsten Heavy Alloys After Hot Rotary Swaging and Annealing

Krátká

2020

METAL 2020 Conference Proeedings

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This study deals with the experimental processing of a tungsten heavy alloy prepared by powder metallurgy using the technology of rotary swaging. Rotary swaging took place at a temperature of 900 ° C. After processing by rotary swaging, the material was further subjected to annealing. Emphasis was placed on the mechanical properties of the material before processing, after processing and after annealing. In the study we also deal with the influence of forming and annealing on the structural arrangement of tungsten heavy alloy.

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Effect of alloying addition and microstructural parameters on mechanical properties of 93% tungsten heavy alloys

Cited by 88 publications

References 11 publications

Effects of Sintering Conditions on Structures and Properties of Sintered Tungsten Heavy Alloy

Effects of Sintering Conditions on Structures and Properties of Sintered Tungsten Heavy Alloy

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

Experimental Verification of Mechanical Properties of Thungsten Heavy Alloys After Hot Rotary Swaging and Annealing

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