碳化硅陶瓷的固相烧结与研磨介质球的制备

发布时间：2018-06-10 19:42

  本文选题：β-SiC + 无压烧结　； 参考：《西安科技大学》2015年硕士论文

【摘要】：碳化硅陶瓷以其优异的性能广泛应用于国防、机械、冶金、电子等工业领域。在众多的陶瓷材料中,碳化硅由于其硬度高、耐高温、热稳定性好、热膨胀系数低以及优良的热传导性能,一直是材料科学研究的热点。本文采用固相烧结法(无压烧结和热压烧结)成功制备了高致密度的碳化硅陶瓷。主要研究了烧结温度、保温时间、热压压力对碳化硅陶瓷性能的影响并确定了最佳工艺参数,用水静力天平、万能拉伸实验机、维氏硬度仪、SEM和XRD对其性能与显微结构做了测试与表征。实验结果表明,无压烧结最佳工艺参数:烧结温度2010℃,保温时间45min,Si C陶瓷体积密度高达3.1261g/cm3,断裂韧性达4.46MPam1/2,抗弯强度达379MPa;热压烧结最佳工艺参数:烧结温度1900℃,保温时间60min,热压压力50MPa,Si C陶瓷体积密度达3.1756g/cm3,断裂韧性达5.12MPam1/2,抗弯强度达596MPa。本文在本课题组前人研究成果的基础上,采用同粒径(1μm)的β-Si C和α-Si C做为实验原料,系统地研究了β-Si C添加量对Si C陶瓷力学性能的影响。研究结果表明,无压烧结和热压烧结β-Si C最优添加量分别为5%和10%,β-Si C烧结后晶粒呈长柱状,添加β-Si C后Si C陶瓷的断裂韧性有较大的提高,相比纯α-Si C制备的陶瓷,无压烧结提高了0.52MPam1/2,热压烧结提高了0.21MPam1/2;无压烧结抗弯强度从341MPa提高到379MPa,热压烧结抗弯强度从527MPa提高到596MPa。本文研究了研磨介质球的制备工艺(滚制成型和冷等静压成型)对研磨介质球密度的影响。滚制成型的球坯烧结密度为2.930g/cm3,1mm、2mm、3mm、4mm、5mm研磨介质球分别在36.8MPa、32.1MPa、29.9MPa、16.1 MPa、13.8MPa的压力环境下压碎值都小于2.08%。1mm~5mm研磨介质球磨损率都小于0.95g/kg·h,其中3mm研磨球的磨损率最低为0.27g/kg·h。球坯冷等静压成型是用石蜡作为密封材料包裹球坯。冷等静压成型球坯的烧结密度能提高到2.958g/cm~3。
[Abstract]:Silicon carbide ceramics are widely used in national defense, machinery, metallurgy, electronics and other industries due to their excellent properties. Among many ceramic materials, silicon carbide has been a hot spot in material science because of its high hardness, high temperature resistance, good thermal stability, low thermal expansion coefficient and excellent thermal conductivity. High density silicon carbide ceramics were prepared by solid state sintering (pressureless sintering and hot pressing sintering). The effects of sintering temperature, holding time, hot pressing pressure on the properties of sic ceramics were studied and the optimum process parameters were determined, such as water static balance, universal tensile tester, The properties and microstructure of Vickers hardness tester were characterized by SEM and XRD. The experimental results show that the optimum process parameters of pressureless sintering are sintering temperature 2010 鈩，

本文编号：2004376