AlN陶瓷低温烧结制备与性能研究

采用两组复合烧结助剂Y2O3-CaF2,Y2O3-CaF2-Li2CO3在1600℃烧结AlN陶瓷,对AlN陶瓷烧结密度,热性能和电性能进行了测试,并分析了AlN陶瓷物相变化和微观结构。结果表明,复合烧结助剂在低温下能明显促进AlN陶瓷致密化及晶粒生长发育,尤其是添加3wt%Y2O3-2wt%CaF2作烧结助剂,1600℃常压烧结4h制备了结晶良好,相对密度为98.4%,热导率为133.62W/m.K,同时具有较低相对介电常数的AlN陶瓷。在低温常压条件下制备出性能较高的AlN陶瓷。     

AlN陶瓷烧结技术及性能优化研究进展

微电子技术的飞速发展对芯片基板和封装材料性能的要求越来越高.AlN陶瓷因其高热导率、高强度、线膨胀系数与硅接近、介电常数小、耐高温和耐腐蚀性能优异而被用作芯片基板和封装材料.主要从烧结技术和烧结助剂对AlN陶瓷性能影响方面综述了AlN陶瓷的研究进展,并指出了AlN陶瓷在制备及应用过程中存在的问题,展望了AlN陶瓷的发展...     

微波烧结AlN陶瓷的初步研究

采用微波高温烧结工艺,制备了致密的AlN陶瓷,并初步探讨了微波烧成环境对烧结体性能的影响.结果表明:利用微波烧结AlN陶瓷,虽然在节能省时方面效果显著,但是微波烧成环境对AlN陶瓷的烧成影响比较复杂,本文着重指出烧成环境中的碳热还原气氛能极大地加快AlN陶瓷的致密化速率,但容易在AlN陶瓷晶界相内部产生气孔,使AlN陶瓷的热导率降低.     

高导热AlN陶瓷烧结助剂的研究现状

在分析了陶瓷的导热机理的基础上，着重评述介绍了几种复合烧结助剂在制备高导热AIN陶瓷过程中的作用机理，对比了AIN陶瓷样品的热导率值。分析了晶界相的形成和AIN晶格的净化，从而减少了氧缺陷，提高了陶瓷材料的致密度和热导率。     

冲击波对AlN粉体性能及低温烧结特性的影响

研究了冲击波对ＡｌＮ粉体性能的影响，并探索了以冲击波处理的ＡｌＮ粉体为原料，添加５％助烧结剂的低温结过程。结果表明，冲击波处理ＡｌＮ粉将使晶粒产生大量的晶格略变，从而活化了粉体。以冲击波处理的ＡｌＮ粉为原料，在１６１０℃下进行无压烧结，可得到密为３．３３ｇ／ｃｍ＾３的ＡｌＮ陶瓷。     

烧结助剂对AlN陶瓷制备及性能的影响

用三组烧结助剂[多壁碳纳米管(multi-wall carbonnanotube,MWNT)、Y2O3-CaF2及MWNT-Y2O3-CaF2]在1600℃低温烧结AlN陶瓷,测试AlN陶瓷烧结密度、热性能和电性能,分析其物相变化和微观结构。结果表明:外添加剂在低温能明显促进AlN陶瓷致密化及晶粒生长发育,并且用合适的埋粉和保护气氛可以防止AlN陶瓷在烧结过程中发生氧化,其中添加质量分数(下同)1%MWNT-3%Y2O3-2%CaF2作烧结助剂,于1600℃保温4h可以制备相对体积密度为97.2%,热导率为138.57W/(m·K),同时具有较低相对相对介电常数的AlN陶瓷,即在低温无压条件下制备性能较高的AlN陶瓷。     

低温烧结氧化铝陶瓷的动力学研究

用CaO-MgO-SiO2玻璃(CMS-G)和TiO2为烧结助剂,在1450℃下实现了氧化铝陶瓷的致密烧结.探讨了CMS-G和TiO2质量百分含量对氧化铝陶瓷烧结性能、显微结构以及其烧结动力学的影响.结果表明:CMS-G和TiO2可有效促进氧化铝陶瓷的致密化,当CMS-G含量为3%、TiO2含量为1%时,氧化铝陶瓷的相对密度达到98.25%;液相烧结激活能为113.4kJ/mol,表明扩散控制了烧结过程.     

氧化铝陶瓷低温烧结助剂的研究进展

本文评述了低温烧结助剂对氧化铝陶瓷烧结效果的影响及烧结助剂在氧化铝陶瓷低温烧结过程中的作用机理,并介绍了几种常用的复相烧结助剂体系及体系中各组分起到的作用,最后指出了目前采用的烧结助剂在进行低温烧结氧化铝陶瓷时存在的不足及需要解决的问题.     

烧结助剂对氮化硅陶瓷显微结构和性能的影响

氮化硅中氮原子和硅原子的自扩散系数很低，致密化所必需的扩散速度和烧结驱动力都很小，在烧结过程中需采用烧结助剂。烧结助剂是影响氮化硅陶瓷的显微结构和性能的关键因素之一。有效的烧结助剂不但可以改善氮化硅陶瓷的显微结构，而且可以提高氮化硅陶瓷的高温性能和抗氧化性能。     

影响氧化铝陶瓷烧结的因素分析

阐述了氧化铝陶瓷的烧结机理 ,分析了烧成气氛、物料分散度及添加熔剂等因素对氧化铝制品烧结程度的影响 ,总结出理想的升温制度、保温时间、绘制烧成曲线。     

Development of a corundum ceramic having a low sintering temperature

Conclusions We obtained a vacuum-tight MKh-1 type corundum material (96% Al₂O₃) having a low (up to 1460°C) sintering temperature. The material possesses high levels of electrophysical and physicotechnological properties, meets the specifications [GOST 20419-83 (ST SÉV 3567-82), group 786.1], and it can be used for producing the insulators of the metal-ceramic assemblies.Translated from Ogneupory, No. 1, pp. 15–18, January, 1986.     

Calcium phosphate based ceramic with a resorbable phase and low sintering temperature

The use of glasses with eutectic compositions in the system CaO-P₂O₅ as a sintering aid and as a source of a resorbable phase for obtaining a composite biomaterial for bone implants is examined. The use of such glass has made it possible not only to lower the sintering temperature by realization of the mechanism of liquid-phase sintering but also to form a ceramic material possessing bioresorbability. The material obtained consists of calcium hydroxyapatite, vitlokite, and calcium pyrophosphate phases. __________ Translated from Steklo i Keramika, No. 7, pp. 19–24, July, 2007.     

Waste derived glass ceramic composites prepared by low temperature sintering/sinter-crystallisation

Glass-ceramics based on iron rich wastes were produced by direct sintering and by following an innovative approach, combining direct sintering and sinter-crystallisation processes. According to the second method, a layered tile was manufactured by single firing at 900°C using a selected combination of wastes for both the porous body and the dense coating layer. The coating layer (‘glaze’) results from the sinter-crystallisation of a waste derived glass mixed with zircon and recycled borosilicate glass. The glaze sealed the porosity of the body and enhanced both mechanical properties and chemical stability. The results show a near to zero water absorption rate, despite a low geometric density (～2?g?cm^??3), accompanied by a Young's modulus of ～40?GPa and a bending strength of ～30?MPa. The chemical stability of the glass-ceramics thus developed was assessed by the application of a toxicity control leaching procedure. Furthermore, cell culture tests were carried out to evaluate the potential cytotoxicity of the materials.     

氮化铝陶瓷基板化学镀镍工艺优化

氮化铝陶瓷基板在化学镀镍生产过程中出现了局部区域起泡、腔体部位发黑的现象。通过故障复现试验,发现原因有二:(1)化学镀前基材钨金属化层在四周边存在亮斑色差,亮斑区域属于二次相聚集,与中间正常区域相比,钨层连续性较差,导致镀层与基材咬合力不足而起泡;(2)在烘干过程中,由于产品倒扣,腔体内部兜水,大量高温下形成的水蒸气在腔体处无法排出,氮化铝与热的水蒸气长时间接触而发生水解反应,导致腔体周围表面变黑。通过对镀前来料的筛选,并在烘干时切水和腔体朝上放置,该问题得到了解决。     

Preparation of AlN ceramic bonded carbon by gelcasting and spark plasma sintering

To obtain light, strong materials with high thermal conductivity, a new carbon-based material, AlN ceramic bonded carbon (AlN/CBC), was fabricated by combining gelcasting and spark plasma sintering techniques. The results showed that AlN/CBC (20 vol% AlN) has a unique microstructure containing carbon grains of 15 μm in size and an AlN grain-boundary layer of 0.5-3 μm in thickness. Continuous AlN ceramic networks bonded the carbon grains together. Compared with the conventional AlN/carbon (AlN/C) material made by a ball-milling method, AlN/CBC showed a higher strength and a higher thermal conductivity by two and four times, respectively.     

Corundum ceramic with a reduced sintering temperature

Translated from Steklo i Keramika, No. 8, pp. 21–22, August, 1992.     

利用粉煤灰低温熔制基础玻璃的研究

以粉煤灰为主要原材料,添加适当的工业级硼酸、石灰石、氧化锌、氧化镁、二氧化硅、碳酸钠作为辅助材料,选择铝硅酸盐系统作为配方,制备基础玻璃。通过DTA和TEM研究不同配比的基础玻璃配方表明,最合理基础玻璃在1 200℃熔制是可行的,粉煤灰的利用率达到了30%以上,最适宜的玻璃组成是(%):S iO245~60,A l2O39~15,CaO 12~20,MgO 2~5,Na2O 3~11,ZnO 2~5,S 0~1,B2O30.5~1.5,F 0~2.5。     

Influence of sintering temperature on microstructural changes of ceramic Raschig ring

The thermal behavior of Illitic-kaolinitic clay for manufacturing of low porosity ceramic Raschig rings was characterized during the sintering process. The samples were shaped by extrusion method and fired at different temperatures from 1,100 to 1,300 °C. The main physical-chemical transformations were studied by evaluating changes in shrinkage, water absorption, porosity, mechanical strength, microstructure and mineralogical compositions. The optimum sintering condition was found to obtain maximum mechanical strength. Chemical resistance of ceramic Raschig rings also was determined according standard method. It was shown that the better chemical resistance could be attributed to the different mineralogical compositions, in particular with presence of mullite phase.     

镁合金固相反应复相陶瓷涂层性能对比

采用固相反应法分别在MB2镁合金基体上制备Al2O3基和SiO2基复相陶瓷涂层,确定了陶瓷涂层的较佳配方如下:SiO2基陶瓷涂层为m(SiO2)∶m(Al2O3)∶m(MgO)∶m(钠长石)=66.8∶13.2∶12∶8,Al2O3基陶瓷涂层为m(A12O3)∶m(SiO2)∶m(MgO)∶m(ZnO)=66∶12∶12∶10,陶瓷料浆与粘接剂质量比为0.5∶1.对所制备的涂层结构,封孔前后涂层的致密性、耐酸性、耐盐水性以及耐磨性进行了测试.结果表明,SiO2基复相陶瓷涂层因在热固化过程中产生大量新相,而提高了涂层的致密性.与镁合金基体相比,封孔后涂层的耐酸性和耐盐水性分别提高了21倍和17倍,相对耐磨性增强了1.94倍,均优于封孔后Al2O3基复相陶瓷涂层的相关性能.