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以碳化硼(B4C)粉为主要原料,硼(B)粉为烧结助剂,氮化硼纳米管(BNNTs)为补强增韧剂,聚乙烯亚胺(PEI)为分散剂,羟丙基甲基纤维素(HPMC)为粘结剂,聚乙二醇(PEG)为增塑剂,采用水基流延成型工艺和热压烧结法制备出BNNTs/B4C层状复合材料。研究了固含量、分散剂含量、增塑剂与粘结剂质量比值(R值)对流延浆料粘度的影响。采用硬度计、万能试验机、X射线衍射仪(XRD)、扫描电镜(SEM)等手段对样品进行了表征。实验结果表明:当PEI、HPMC、PEG的加入量分别为1.5%、5%和5%(质量分数,下同)时可获得固含量为45%的B4C水基流延浆料。样品于2050℃、30 MPa下热压30 min可获得致密度高达97.5%的BNNTs/B4C层状复合材料,其维氏硬度、抗弯强度、断裂韧性分别达38.2 GPa、516.34 MPa和6.97 MPa·m1/2。
Boron (B) powder as sintering aids, BNNTs as toughening toughening agent, polyethyleneimine (PEI) as dispersing agent, hydroxypropyl BNNTs / B4C layered composites were prepared by a water-based casting process and hot-pressing sintering using methylcellulose (HPMC) as a binder and polyethyleneglycol (PEG) as a plasticizer. The effects of solid content, dispersant content and mass ratio of plasticizer to binder (R value) on the viscosity of cast slurry were investigated. The samples were characterized by hardness tester, universal testing machine, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The experimental results show that B4C water-based casting slurry with 45% solid content can be obtained when the contents of PEI, HPMC and PEG are 1.5%, 5% and 5%, respectively. The BNNTs / B4C layered composites with the highest density of 97.5% were obtained by hot pressing at 2050 ℃ and 30 MPa for 30 min. The Vickers hardness, flexural strength and fracture toughness were 38.2 GPa, 516.34 MPa and 6.97 MPa · m1 / 2.