Gd_(2-x)Nd_xZr_2O_7(Nd=An(Ⅲ),0≤x≤2.0)模拟固化体固溶量与其物相、密度、硬度之间的关系

Relation of containment capacity with phase composition,density and Vickers hardness of simulated waste forms Gd_(2-x)Nd_xZr_2O_7(Nd = An(Ⅲ),0≤x≤2.0)

以Nd(Ⅲ)作为放射性核素An(Ⅲ)的模拟替代物,以Gd_2O_3和ZrO_2粉体为原料,通过高温固相反应法(1500℃,保温72 h)合成了Gd_(2-x)Nd_xZr_2O_7(0≤x≤2.0)微米级的钆锆烧绿石固化An(Ⅲ)的模拟固化体.利用X射线衍射仪、显微硬度计和扫描电子显微镜等对所制备样品的物相、密度、维氏硬度和微观形貌进行了表征.结果表明:Gd_(2-x)Nd_xZr_2O_7(0≤x≤2.0)系列固化体样品多呈板状,均为烧绿石相;其密度值随固溶量x值的增加,呈逐渐下降趋势,但均≥5.76 g·cm^(-3).固化体的维氏硬度值(H_v)随x值的递增呈逐渐减小趋势,x值与维氏硬度值之间满足H_v=695.18636-162.64091 x的线性关系,但维氏硬度值均≥400kg·mm^(-2)以上.

In order to investigate the capability of Gd2Zr2O7 pyrochlore as a waste form for immobilizing trivalent actinides nuclides, Nd（Ⅲ） is used as an alternative substance for An（Ⅲ）. The compounds in the system Gd2-xNdxZr2O7 （0≤ x ≤ 2.0） are synthesized at 1500 ℃ for 72 h by high temperature solid state reaction method, using Gd2O3 and ZrO2 powders as the raw materials. The phase, intensity, Vickers hardness and microcosmic shape are characterized by X-ray diffraction, Vickers hardness tester, scanning electron microscopy and so on. The results indicate that the phase of synthesized waste form with plate-shape keeps the phase of pyrochlore. The intensity of compound slightly decreases with the increase of the containment capacity value x, but it is above 5.76 g·cm-3. The value of Vickers hardness also decreases with the increase of x. The values of x and Vickers hardness are linearly related by HV=695.18636-162.64091 x （HV≥ 400 kg·mm-2）.