CAJ | 학술논문

采用放电等离子烧结(SPS)技术,以碳化硼还原法制备的LaB_6粉末为原料,制备了高致密LaB_6多晶块体阴极,并系统研究了烧结温度、压力对LaB_6烧结样品的物相、结构和性能的影响.确定了SPS烧结LaB_6的最佳工艺为:压力50 MPa,烧结温度1 650 ℃,保温时间10 min.实验结果表明:与其它LaB_6多晶制备方法相比,SPS制备得到的LaB_6烧结块体的力学及发射性能均有大幅提高,样品相对密度达到96.2%,维氏硬度达到1 720 kg/mm~2,抗弯强度达到203.2 MPa.样品在1 520 ℃温度下发射电流密度达到17.41 A/cm~2,功函数为2.40 eV.SPS制备法显著降低了LaB_6的烧结温度,缩短了烧结时间.
채용방전등리자소결(SPS)기술,이탄화붕환원법제비적LaB_6분말위원료,제비료고치밀LaB_6다정괴체음겁,병계통연구료소결온도、압력대LaB_6소결양품적물상、결구화성능적영향.학정료SPS소결LaB_6적최가공예위:압력50 MPa,소결온도1 650 ℃,보온시간10 min.실험결과표명:여기타LaB_6다정제비방법상비,SPS제비득도적LaB_6소결괴체적역학급발사성능균유대폭제고,양품상대밀도체도96.2%,유씨경도체도1 720 kg/mm~2,항만강도체도203.2 MPa.양품재1 520 ℃온도하발사전류밀도체도17.41 A/cm~2,공함수위2.40 eV.SPS제비법현저강저료LaB_6적소결온도,축단료소결시간.
High density LaB_6 polycrystalline bulks were fabricated by spark plasma sintering(SPS) LaB_6 powders prepared by boron carbide reduction method. The effects of sintering temperature and pressure on the phase formation, microstructure and properties of the sintered LaB_6 bulks were studied systematically. The optimal technological parameters are sintering temperature of 1 650 ℃, sintering pressure of 50 Mpa and holding time of 10 mins. It is shown that, the mechanical and emissive properties of the sintered LaB_6 bulks are much better than that prepared by other methods. The relative density of the LaB_6 sintered by SPS is up to 96.2%, and its vickers hardness reaches 1 720 kg/mm~2. The highest bend strength is 203.2 Mpa. The electron emitting density of the polycrystalline LaB_6 sintered by SPS is 17.41 A/cm~2 at 1 520 ℃, and the work function is 2.40 eV. SPS method obviously decreases the sintering temperature of LaB_6 and shortens the sintering time.