Ti-B-C-N粉末烧结的微观组织及其性能

Microstructure and properties of sintered Ti-B-C-N power

以Ti-B-C-N四元相陶瓷粉末为实验材料,采用真空热压烧结和放电等离子烧结(SPS)工艺对其进行烧结,真空热压烧结和放电等离子烧结温度分别为1900℃和1450℃,烧结压力分别为20 MPa和40 MPa,保温时间分别为1h和3min。使用X射线衍射仪分析试样物相组成,扫描电子显微镜观察试样表面微观形貌和断口形貌,并测试了烧结试样的硬度和抗弯强度。结果表明:真空热压烧结和放电等离子烧结块体的主要生成相为TiB2相和TiCN相,相对密度分别为97.40%和93.06%,热压烧结试样致密度高,颗粒尺寸大,放电等离子烧结试样孔隙较多,晶粒尺寸小;抗弯强度分别为259.98 MPa和335.17 MPa;弹性模量分别为89.11GPa和162.92GPa;洛氏硬度分别为78.8和84.9;放电等离子烧结试样表现出较好的力学性能。

Ti-B-C-N power was sintered by hot pressing sintering and spark plasma sintering methods. The sintering temperatures were 1900 ℃ and 1450 ℃, the sintering pressing pressures were 20 MPa and 40 MPa, and the sintering times were 1 h and 3 min, respectively. The phase composition wa analyzed using X-ray Diffraction （XRD）. The surface morphology and fracture morphology of the sintered samples were observed with Scanning Electron Microscope （SEM）. The hardness and transverse rupture strength of the sintered samples were investigated. The results show that the sintered samples were mainly composed of phases TiB2 and TiCN, the relative densities were 97.40% and 93.06%. The density of hot pressing sample was higher and particle size was significantly grown up. The transverse rupture strengths were 259.98 MPa and 335.17 MPa, the hardness （HRA） were 78.8 and 84.9, the elastic moduli were 89.11 GPa and 162.92 GPa, respectively. The spark plasma sintered samples show better mechanical properties.