{"title":"Synthesis of niobium boride powder by solid state reaction between niobium and amorphous boron","authors":"Tsuneaki Matsudaira, Hideaki Itoh, Shigeharu Naka, Hiroshi Hamamoto","doi":"10.1016/0022-5088(89)90229-4","DOIUrl":null,"url":null,"abstract":"<div><p>Niobium boride powders were synthesized by solid state reaction between niobium metal powder and amorphous boron powder. The formation of niobium borides was found to be dependent on temperature. Single phases of the stable borides, NbB and NbB<sub>2</sub>, were formed by heating mixed powders corresponding to the stoichiometric compositions at 1000 °C for 60 min. A single phase of Nb<sub>3</sub>B<sub>4</sub> was obtained at a higher temperature of 1800 °C as a result of the promoted diffusion of boron atoms in niobium metal. All synthesized powders were well dispersed and had particle sizes of 5–10 μm. The sinterability of the synthesized NbB<sub>2</sub> powder was evaluated at high pressure (4 GPa) and temperature (1600 °C) for 15 min; a single-phase sintered compact of NbB<sub>2</sub> was formed with a relative density of 98% and a Vickers microhardness of 2600 kg mm<sup>−2</sup>.</p></div>","PeriodicalId":17534,"journal":{"name":"Journal of The Less Common Metals","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"1989-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0022-5088(89)90229-4","citationCount":"40","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of The Less Common Metals","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/0022508889902294","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 40
Abstract
Niobium boride powders were synthesized by solid state reaction between niobium metal powder and amorphous boron powder. The formation of niobium borides was found to be dependent on temperature. Single phases of the stable borides, NbB and NbB2, were formed by heating mixed powders corresponding to the stoichiometric compositions at 1000 °C for 60 min. A single phase of Nb3B4 was obtained at a higher temperature of 1800 °C as a result of the promoted diffusion of boron atoms in niobium metal. All synthesized powders were well dispersed and had particle sizes of 5–10 μm. The sinterability of the synthesized NbB2 powder was evaluated at high pressure (4 GPa) and temperature (1600 °C) for 15 min; a single-phase sintered compact of NbB2 was formed with a relative density of 98% and a Vickers microhardness of 2600 kg mm−2.
采用金属铌粉末与非晶态硼粉末固相反应合成了硼化铌粉末。铌硼化物的形成与温度有关。通过在1000°C下加热对应于化学计量组成的混合粉末60分钟,形成稳定硼化物的单相NbB和NbB2。由于硼原子在铌金属中的促进扩散,在1800°C的更高温度下获得了Nb3B4的单相。所有合成的粉末都分散良好,颗粒尺寸为5–10μm。在高压(4GPa)和高温(1600°C)下对合成的NbB2粉末的可烧结性进行了15分钟的评估;形成了相对密度为98%、维氏显微硬度为2600 kg mm−2的NbB2单相烧结体。