The temporal interface microstructures and diffusions in the diffusion couples with the mutual interactions of the temperature gradient, concentration difference and initial aging time of the alloys are studied by pha...The temporal interface microstructures and diffusions in the diffusion couples with the mutual interactions of the temperature gradient, concentration difference and initial aging time of the alloys are studied by phase-field simulation, and the diffusion couples are produced by the initial aged spinodal alloys with different compositions. Temporal composition evolution and volume fraction of the separated phase indicate the element diffusion direction through the interface under the temperature gradient. The increased temperature gradient induces a wide single-phase region on two sides of the interface.The uphill diffusion proceeds through the interface, no matter whether the diffusion direction is up or down with respect to the temperature gradient. For an alloy with short initial aging time, phase transformation accompanying the interdiffusion results in the straight interface with the single-phase regions on both sides. Compared with the temperature gradient,composition difference of diffusion couple and initial aging time of the alloy show greater effects on diffusion and interface microstructure.展开更多
The liquid-film solution-diffusion bonding of ZCuBe2.5 alloys was conducted using Cu-based alloy powders. The tensile strength of the joint is up to 318 MPa. With the increase of temperature gradient, the bonding time...The liquid-film solution-diffusion bonding of ZCuBe2.5 alloys was conducted using Cu-based alloy powders. The tensile strength of the joint is up to 318 MPa. With the increase of temperature gradient, the bonding time decreases and the interface migration velocity increases remarkably. The appropriate temperature gradient is 5-40 K/cm. Under fixed bonding time, the thickness of diffusion layer increases with the increase of temperature gradient, and this tendency becomes more remarkable with the prolonging of bonding time.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.51571122)the Fundamental Research Funds for the Central UniversitiesChina(Grant No.30920130121012)
文摘The temporal interface microstructures and diffusions in the diffusion couples with the mutual interactions of the temperature gradient, concentration difference and initial aging time of the alloys are studied by phase-field simulation, and the diffusion couples are produced by the initial aged spinodal alloys with different compositions. Temporal composition evolution and volume fraction of the separated phase indicate the element diffusion direction through the interface under the temperature gradient. The increased temperature gradient induces a wide single-phase region on two sides of the interface.The uphill diffusion proceeds through the interface, no matter whether the diffusion direction is up or down with respect to the temperature gradient. For an alloy with short initial aging time, phase transformation accompanying the interdiffusion results in the straight interface with the single-phase regions on both sides. Compared with the temperature gradient,composition difference of diffusion couple and initial aging time of the alloy show greater effects on diffusion and interface microstructure.
文摘The liquid-film solution-diffusion bonding of ZCuBe2.5 alloys was conducted using Cu-based alloy powders. The tensile strength of the joint is up to 318 MPa. With the increase of temperature gradient, the bonding time decreases and the interface migration velocity increases remarkably. The appropriate temperature gradient is 5-40 K/cm. Under fixed bonding time, the thickness of diffusion layer increases with the increase of temperature gradient, and this tendency becomes more remarkable with the prolonging of bonding time.
