As a typical tungsten-based composite consisting of tungsten(W)particles and matrix phase,tungsten heavy alloys(WHAs)are extensively utilized in the military due to their exceptional strength and high density.However,...As a typical tungsten-based composite consisting of tungsten(W)particles and matrix phase,tungsten heavy alloys(WHAs)are extensively utilized in the military due to their exceptional strength and high density.However,the large grain size(>30μm)of powder metallurgy liquid phase sintered(LPS)WHAs and the low strength of the matrix phase limit the further improvement of the alloy.In this work,high-density ultrafine WHAs were fabricated by two-step low-temperature sintering,and the density of the alloy reached 17 g/cm^(3) with an average W particle size of 7.81μm.Additionally,the eutectic reaction be-tween Ni and Ta was controlled to generate dispersed nano-Ni_(3)Ta phases in situ in the matrix phase,fur-ther improving the strength of the alloy.Under the synergistic strengthening effect of fine-grain strength-ening,dispersion strengthening,and solid solution strengthening,the average ultimate tensile strength of the alloy reached 1190.39 MPa.At the same time,the alloy maintained good elongation with a total elon-gation of 20.8%due to the good co-grid interface orientation between the Ni_(3)Ta phase and the matrix phase.This study provides a new idea for developing high-strength WHAs and has a guiding significance for developing Ni-based alloys.展开更多
基金supported by the National Natural Science Foundation of China(No.51701242,51931012)the Science and Technology Innovation Program of Hunan Province(No.2023RC3068).
文摘As a typical tungsten-based composite consisting of tungsten(W)particles and matrix phase,tungsten heavy alloys(WHAs)are extensively utilized in the military due to their exceptional strength and high density.However,the large grain size(>30μm)of powder metallurgy liquid phase sintered(LPS)WHAs and the low strength of the matrix phase limit the further improvement of the alloy.In this work,high-density ultrafine WHAs were fabricated by two-step low-temperature sintering,and the density of the alloy reached 17 g/cm^(3) with an average W particle size of 7.81μm.Additionally,the eutectic reaction be-tween Ni and Ta was controlled to generate dispersed nano-Ni_(3)Ta phases in situ in the matrix phase,fur-ther improving the strength of the alloy.Under the synergistic strengthening effect of fine-grain strength-ening,dispersion strengthening,and solid solution strengthening,the average ultimate tensile strength of the alloy reached 1190.39 MPa.At the same time,the alloy maintained good elongation with a total elon-gation of 20.8%due to the good co-grid interface orientation between the Ni_(3)Ta phase and the matrix phase.This study provides a new idea for developing high-strength WHAs and has a guiding significance for developing Ni-based alloys.
