【摘要】 氮化硅陶瓷力学性能优异,理论热导率高,是大功率电力电子器件的关键热管理材料。但是,高导热氮化硅陶瓷烧结温度高、保温时间长,因此制备成本居高不下,对于产业化应用不利。本研究提出了一种快速制备高导热氮化硅陶瓷的方案。以Y₂O₃-MgO-C作为烧结助剂,以高纯硅粉作为起始原料,通过流延成型和硅粉氮化制备素坯,在1900℃、0.6MPa保温2h制备出高导热氮化硅陶瓷。研究了C的添加量对于氮化硅陶瓷的致密化、晶相、微结构、力学性能以及热导率的影响规律。最终制备的氮化硅陶瓷密度可以达到99%以上,热导率达到98W/m·K。更多还原

【Abstract】 Si₃N₄ ceramics are prospective substrate candidates for power electron devices because of the excellent mechanical properties and high theoretical thermal conductivity.However,the development of high thermal conductivity Si₃N₄ is quite difficult,because the high sintering temperature and long holding time under N₂ pressure lead to high production cost,which is not conductive to industrial applications.In this paper,a relative fast preparation process was proposed using Y₂O₃-MgO-C as the sintering additive and silicon powder as the starting material.High thermal conductivity Si₃N₄ ceramic was prepared through tape casting,nitridation and gas pressure sintering at 1900℃,0.6 MPa with 2 hholding.The influences of carbon addition on the sintering behavior,phase,microstructure,mechanical properties and thermal conductivity of Si₃N₄ were studied.Finally Si₃N₄ ceramics with the relative density of 99% and the thermal conductivity of 98 W/m K were obtained.更多还原