摘要
采用熔体冷却法,制得了Bi_(2)O_(3)-B_(2)O_(3)二元、CuO-B_(2)O_(3)二元、CuO-Bi_(2)O_(3)-B_(2)O_(3)三元系统的一系列样品。针对肉眼可见存在未熔融、未完全熔融、玻璃光泽差、有絮状物、分层等现象的样品,采用XRD对其进行物相鉴定,并以此为据判断各配方的玻璃形成能力,从而确定了CuO-Bi_(2)O_(3)-B_(2)O_(3)三元系统的玻璃形成范围。研究结果表明:CuO-Bi_(2)O_(3)-B_(2)O_(3)三元系统中,B_(2)O_(3)含量低于15 mol%的配方均不能制得玻璃。熔体冷却过程中析出Bi_(2)O_(3)、CuBi_(2)O_(4)等晶相。当配方中的B_(2)O_(3)含量超过70 mol%时,制得的玻璃样品易分相和开裂;当配方中的B_(2)O_(3)含量为50 mol%~70 mol%时,Bi_(2)O_(3)含量超过15 mol%才能制得玻璃;而当配方中的B_(2)O_(3)含量为45 mol%~50 mol%时,Bi_(2)O_(3)含量只要不低于5 mol%就能制得玻璃。当B_(2)O_(3)含量从45 mol%降低至15 mol%时,提高Bi_(2)O_(3)/CuO比才能制得玻璃,否则熔体在冷却过程中易析出Cu_(2)O晶体。CuO-Bi_(2)O_(3)-B_(2)O_(3)三元系统具有较宽的玻璃形成范围及较高的CuO的掺入量,且玻璃中CuO的掺入量随Bi_(2)O_(3)含量的增加而降低。玻璃中CuO和Bi_(2)O_(3)的最高掺入量分别为50 mol%和75 mol%。
[Background and purposes]Bismuth borate glasses reported in literature mainly include Bi_(2)O_(3)-B_(2)O_(3),Bi_(2)O_(3)-ZnO/BaO/PbO-B_(2)O_(3),Bi_(2)O_(3)-ZnO-B_(2)O_(3)-SiO_(2) systems.In transition metal doped bismuth borate glasses,CuO-doped Bi_(2)O_(3)-B_(2)O_(3) glasses have been rarely studied,while the doping concentration of CuO is usually less than 10 mol%.It has been indicated that the doping of CuO in bismuth borate glass has several advantages.Firstly,it helps to increase the density of the glass,thus making the liquid phase to be at a lower temperature.Secondly,it improves the alkaline resistance of glass.Thirdly,the thermal expansion coefficient of the glass has a very weak change,while slightly reducing the characteristic temperature of the glass,which benefits its application at low temperatures.The current authors found that high concentrations of Cuo[specifically in(40-x)ZnO-xCuO-40Bi_(2)O_(3)-20B_(2)0_(3)(x>20 mo1%)system]lead to the precipitation of crystalline phases during the sintering process,adversely impacting the fluidity and thermal expansion coefficient of the solder and hence complicating the sealing processes.To systematically study the influence of CuO concentration on the composition,structure,and properties of bismuth borate glass,it is imperative to first study the glass formation range in the CuO-Bi_(2)O_(3)-B_(2)O_(3) ternary system and identify glass compositions from the view of practical applications.In oxide-doped bismuth borate glasses,the glass formation region,of PbO/ZnO/Ba-Bi_(2)O_(3)-B_(2)O_(3),CaO/SrO-Bi_(2)0_(3)-B_(2)0_(3) and TeO2-Bi_(2)O_(3)-B_(2)0_(3),has been reported,while the glass formation region of CuO-BizO3-B2O,ternary system has not been presented.[Methods]Analytical grade raw materials,including Bi_(2)O_(3),CuO and H,BO3,were weighed according to ratio of each composition and ball milled to obtain glass batch.The batch is then placed in a corundum crucible and heated in an electric furnace to 1000℃ for 1 h.After that,the molten glass is poured into molds,annealed and subsequently cooled within the furnace to obtain solid glass blocks.X-ray diffraction(XRD)is utilized for characterization of the samples exhibiting incomplete melting,poor glass luster,flocculation,stratification or other anomalies visible to the naked eye.The glass forming ability is evaluated based on sample appearance and XRD results,thereby establishing the glass formation region of the CuO-Bi_(2)O_(3)-B_(2)O_(3)ternary system.[Results]The content of Bi_(2)O_(3) in the Bi2O3-B_(2)0,binary glass is found to be in the range from 30 mo1%to 70 mol%.Samples with Bi2O3 content<30 mol%exhibit tendency of phase separation,whereas the samples with>70 mo1%Bi_(2)0_(3)results in the precipitation of Bi_(2)O_(3).In the CuO-B_(2)O binary system,samples with high CuO concentrations demonstrate strong crystallization,leading to the precipitation of Cu2O and aluminium-containing crystalline phases.Conversely,samples with lower CuO contents are amorphous but lack glass lustre,rendering them unsuitable for practical applications,while also exhibiting severe corrosion of the alumina crucible.In the CuO-Bi_(2)O-B_(2)O,ternary glass,maintaining Bi2O,content at 5 mol%,while controlling CuO or B_(2)O_(3) content to below 55 mol%,facilitates the production of uniform glass,with CuO concentrations up to 50 mol%.An increase in the content of BizO3 significantly enhances the glass formation ability and thermal stability,with the maximum CuO concentration in glass compositions containing 10-20 mo1%Bi_(2)O_(3) reaching 40 mol%.For samples with Bi_(2)O_(3) content exceeding 20 mol%,the maximum permissible CuO concentration is limited to 30 mo1%.[Conclusions]Homogeneous glasses cannot be prepared from compositions with the content of B_(2)O,below 15 mol%in the CuO-Bi_(2)O ternary system,because of the precipitation of Bi2O and CuBi2O4 crystalline phases during the cooling process of the melts.Compositions with>70 mol%B_(2)O,also fail to produce glass with practical utility,as they are prone to phase separation and cracking.Compositions with B_(2)O_(3) content in the range of 50-70 mol%can favorably produce glass,when the content of Bi_(2)O_(3) is no less than 15 mol%.Additionally,glass can be formed provided Bi_(2)O_(3) content is not less than 5 mol%,when the content of B_(2)0_(3) ranges from 45 mo1%to 50 mo1%.When the B203 content is reduced from 45 mo1%to 15 mo1%,glass can be prepared by increasing the ratio of Bi2Os/CuO.Otherwise,Cu_(2)O crystals tend to crystallize from the melt during the cooling process.The CuO-Bi_(2)O_(3)-B_(2)O;ternary system has a wide glass formation region,where the maximum contents of CuO and Bi_(2)0 in the glass are 50 mol1% and 75 mol%,respectively.
作者
郭慧明
李秀英
LAWRENCE Cooper
GUO Huiming;LI Xiuying;LAWRENCE Cooper(School of Material Science and Engineering,Jingdezhen Ceramic University,Jingdezhen 333403,Jiangxi,China)
出处
《陶瓷学报》
北大核心
2025年第4期750-758,共9页
Journal of Ceramics
基金
江西省自然科学基金面上项目(20242BAB25222)
江西省教育厅科学技术研究项目(GJJ2201013)
江西省研究生创新专项资金项目(YC2023-s808)。
关键词
铋硼酸玻璃
物相鉴定
玻璃形成范围
bismuth borate glass
phase identification
glass forming region
作者简介
通信联系人:李秀英(1980-),女,博士,副教授。
