在Ni基底上电镀Te薄膜,然后在不同温度下对样品进行相同时间的真空热处理,经室温拉断后测得样品沿晶界断裂深度Ⅳ。通过拟合In(X2/t)与1/T的线性关系求出扩散激活能,得出中低温段Te在纯Ni中的晶界扩散系数,并对实验结果和计算进行了讨论。结果表明,在Ni表面镀Te条件下,随温度的升高,Ni的抗拉强度及延伸率急剧下降,试样断口上的沿晶断裂深度逐渐增大;计算得出Te沿纯Ni晶界扩散的激活能为152kJ/tool,并得出在500℃到1000℃之间的扩散系数表达式为:D=0.83×10-2exp(-18360/T)cm。/s。
The diffusion behavior of tellurium (Te) into pure nickel (Ni) was investigated under vacuum condition at different annealing temperatures by electroplating. The intergranular fracture depth (x) was measured by observing the fracture surface of tensile test specimen. The diffusion activation energy and diffusion coefficient were figured out through fitting the linear relationship between In (xZ/t) and 1/T. The results showed that ultimate tensile strength and elongation of Ni decreased dramatically with the temperature increasing within the range of 500 ℃ to 1 000℃,while the depth of intergranular fracture increased gradually on the fracture morphology. It was calculated that the diffusion activation below 1 000 ℃, and the formula of diffusion energy of Te in Ni was 152 coefficient was:D =0.83 x 10 kJ/mol at the temperature 2exp( - 18 360/T) cm2/s.