摘要
采用放电等离子烧结工艺（spark plasma sintering，简称SPS）在氮气气氛中制备了以Si3N4-AlN-Al2O3-Y2O3系为基的立方氮化硼聚晶（polycrystalline cubic boron nitride，简称PcBN）。烧结工艺参数为：加热速率300℃/min，初始压力30 MPa，保温时间5 min，烧结温度分别为1250℃、1350℃和1450℃。利用X射线衍射分析（XRD）和扫描电子显微镜（SEM）对样品的物相构成和试样新鲜断口的微观形貌进行了分析和观察，同时利用显微硬度测试仪测试了样品的显微硬度。实验结果表明，Si3N4-AlN-Al2O3-Y2O3-BN系聚晶材料可以在非常短的时间内致密化，样品的相对密度可达95%以上。采用SPS快速烧结工艺，样品中的超硬磨料cBN依然保持立方结构。随着烧结温度的提高，样品的硬度不断增加，PcBN的显微硬度为28-48 GPa。结合剂组份可与立方氮化硼牢固地结合在一起。放电等离子烧结工艺可成为制备PcBN刀具材料的一种新的制备方法。
Using Si3N4-AlN-Al2O3-Y2O3 ceramic system as binding, polycrystalline cubic boron nitride （PcBN） was prepared by spark plasma sintering （SPS）. The samples were heated under a sintering temperature between 1250℃ and 1450℃ at a heating rate of 300 ℃/min, with a holding time of 5 min in nitrogen atmosphere. The microstructure, phase constitution, microhardness of samples were studied by XRD, SEM and micro hardness tester. The results showed that the Si3N4-AlN-Al2O3-Y2O3-BN system polycrystalline materials could be densified in very short sintering time; the relative density of material could be more than 95%. When the sintering temperature increased,the microhardness of samples increased also. The microhardness of PcBN was 28 - 48 GPa. The binding agent could be bonded with cubic boron nitride particles firmly. Spark plasma sintering technology could become a novel preparation method of PcBN cutter materials.
出处
《金刚石与磨料磨具工程》
CAS
北大核心
2007年第4期22-24,共3页
Diamond & Abrasives Engineering
基金
河北省自然科学基金项目(E2006000226)
