热压烧结制备高密度ZrB_2陶瓷

PREPARATION OF HIGH DENSITY ZrB_2 CERAMICS BY HOT-PRESSING

在烧结温度和压力为1950℃和50MPa条件下,分别对ZrB2的原始粉末、球磨粉末、加助烧剂的粉末以及既加助烧剂又进行球磨的粉末进行热压烧结实验。采用阿基米德排水法测出了ZrB2陶瓷的密度;利用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、能谱(EDS)等手段对粉体和烧结产物的物相、形貌以及成分进行了表征。结果表明:球磨且加助烧剂镍的粉体烧结所得样品致密性最好,相对密度为99.375%,接近全致密;球磨细粉烧结所得样品次之,相对密度为99.09%;添加助烧剂粉末烧结所得样品相对密度为91.45%;用原始粉末烧结所得样品致密性最差,相对密度为84.7%。采用排水法所测得密度结果与扫描电镜观察所得致密性情况一致。

Four kinds of ZrB2 powders were sintered at 1950℃ under a uniaxial load of 50 MPa by hot-pressing respectively.They are original powders,milled powders,powders with additive and milled powders with additive.The phase constituents and compositions of ZrB2 powders and ceramics were analyzed by X-ray diffraction（XRD） and X-ray energy dispersion spectroscope（EDS）.The microstructures of samples were observed by scanning electron microscope（SEM） and Transmission Electron Microscope（TEM）.The densities were measured based on Archimedes drainage method;Results indicate that product sintered by milled powders with additive has the highest density,it can reach 99.375% of its theory density and almost be full density.And sintered body made by milled powders get a relative density of 99.09%.Product produced by powders with additive has a 91.45% relative density.Sintered body made by original powders has a relative density of 84.7%,and that is the lowest one of the four products.And the results measured by Archimedes drainage method are consistent to the results of SEM.