钻削工艺参数对氟金云母玻璃陶瓷材料去除率的影响

对氟金云母可加工玻璃陶瓷进行钻削加工,用扫描电镜观察材料的已加工表面,分析氟金云母玻璃陶瓷钻削加工特性,考察刀具材料、冷却条件、主轴转速、刀具角度等参数对可加工陶瓷材料去除率的影响.结果表明:刀具材料和冷却方式是影响玻璃陶瓷材料加工去除的主要因素.因为存在刀具的磨损,氟金云母玻璃陶瓷的钻削加工应选用硬质合金刀具,而不选用高速钢刀具.采用冷却可以大幅提高加工效率.选择适当的钻削工艺参数,可以提高氟金云母玻璃陶瓷的材料去除率.     

烧成温度对反应析晶法制备可加工氟闪石玻璃陶瓷的影响

将氟云母晶体粉末与普通窗玻璃粉末直接混合后烧结制备出可加工氟闪石玻璃陶瓷,与传统的玻璃陶瓷制备工艺不同的是:氟闪石晶体不是从母相玻璃中直接析出,而是通过氟云母和玻璃间的反应析出.用X射线衍射、扫描电镜分析了氟闪石的反应析晶和玻璃陶瓷的组织,研究了烧成温度对玻璃陶瓷密度、可加工性和抗压强度的影响.结果表明:随着烧成温度的提高,氟闪石反应析晶速度加快,玻璃陶瓷加工性得到改善,但密度和强度下降.900℃烧结2h制备的玻璃陶瓷具有良好的可加工性和较高的强度.     

SiO_2—Al_2O_3—MgO—K_2O—MgF_2系玻璃陶瓷析晶机理及断裂机制

以SiO2—Al2O3—MgO—K2O—MgF2体系玻璃为基础,采用整体析晶法,在高温条件下制备出堇青石/氟金云母玻璃陶瓷。借助于综合热分析仪、X射线衍射仪和扫描电子显微镜等分析手段,研究了玻璃陶瓷的析晶机制、显微形貌和断裂机制。结果表明:所制备的玻璃陶瓷主晶相为板条状氟金云母和β-堇青石,经1 000℃保温3h热处理后,主晶相转变为镁橄榄石;以堇青石和氟金云母为主晶相的玻璃陶瓷断裂机理为穿晶断裂,以镁橄榄石为主晶相的玻璃陶瓷为沿晶断裂。在基础玻璃中添加5%B2O3,可抑制氟金云母相的析出,并提高玻璃陶瓷的致密度。     

反应析晶烧结法制备可加工氟闪石玻璃陶瓷致密化研究

采用两种加热方式对氟云母晶体和普通钠钙玻璃混合粉末进行烧结,用扫描电镜观察烧结过程中玻璃陶瓷的组织演变,结合样品收缩率和密度的变化,研究了玻璃陶瓷的致密化行为.研究结果表明,致密化是通过玻璃的粘性流动实现的,氟云母加入对玻璃粘性流动有阻碍,降低了烧结驱动力.加热至850 ℃,氟云母与玻璃发生反应析晶形成氟闪石,对致密化影响很大.反应析晶发生前,玻璃陶瓷的密度随温度升高和等温时间延长而提高;反应析晶发生后,逐渐形成密集的相互交织的氟闪石晶体骨架对玻璃粘性流动产生严重阻碍,玻璃陶瓷的密度随温度升高略有下降.     

云母-透辉石可加工复合材料的制备

可加工氟云母微晶玻璃是一个有吸引力的材料,可以用在生物、化工等领域。然而,低的机械强度,又限制了其应用。为了改善其机械强度,引入透辉石基玻璃。当透辉石基玻璃引入量为40%时其性能最好,在1010℃下烧结可以得到抗弯强度达148.5MPa的可加工复合微晶玻璃。     

锆英石颗粒增强氟金云母可加工陶瓷制备工艺研究

以氟金云母、玻璃粉、锆英石为主要原料,研究了锆英石对可加工陶瓷显微结构及性能的影响。结果发现:添加锆英石不会影响氟金云母的物相组成和微观结构;锆英石的加入有助于提高试样的致密性和力学性能,经1130℃烧结制得的添加10 wt%锆英石的氟金云母可加工陶瓷具有最佳的力学性能,其抗弯强度和断裂韧性分别达到105.85 MPa和1.88 MPa·m~(1/2),较原始氟金云母可加工陶瓷的力学性能分别提升了89.02%和3.87%;通过脆性指数判断,添加锆英石之后,氟金云母陶瓷仍然具有良好的可加工性能。     

云母微晶玻璃析晶动力学的研究

采用差热分析的方法，对ＴｉＯ２作为晶核剂的氟金云母生晶玻璃的析晶动力学参数进行了测定。结果表明：ＴｉＯ２使原始玻璃在晶化过程中产生了先析相钛酸镁，降低了氟金云母相的析晶活化能；氟金云母晶体以二维片层状方式生长，其生长过程受界面过程控制。     

可加工陶瓷材料的机械加工技术

介绍云母玻璃陶瓷、氧化物陶瓷和非氧化物陶瓷3类可加工陶瓷材料的显微结构特性与材料可加工性的关系，层片状结构与弱界面使陶瓷材料具备可加工性。分析了可加工陶瓷材料机械加工过程中的特性；适宜的加工工艺参数、低加工损伤及材料的沿晶界断裂模式。结合金属材料的可加工性研究，讨论了适于陶瓷材料可加工性评价的研究方法。     

大尺寸电绝缘陶瓷的制备与性能

可加工氟金云母陶瓷很难烧结致密,通过微晶玻璃工艺制造的氟金云母材料的直径一般不超过150 mm,长度不大于300 mm.据此研究了原料颗粒尺寸以及烧结助剂对氟金云母烧结的影响,采用粉料合成和处理、等静压成型以及常压烧成等陶瓷工艺途径,制造了直径大于200 mm,长度超过500 mm的柱状、圆筒状材料.制品的电击穿强度大于30 kV/mm,在标准大气压下测得的表面闪络强度(充N2/SF6气)为(35 5) kV/cm.     

锂云母对铝矾土尾矿低温烧结制备莫来石–刚玉复相陶瓷力学性能的影响

铝矾土尾矿是一种具有挑战性的固体废弃物，利用前景相对较小，大量堆存破坏生态环境，是铝土矿实现可持续开发利用过程中亟需解决的问题。以铝矾土尾矿为主要原料，添加铝矾土熟料、锂瓷石制备了莫来石–刚玉质复相陶瓷，通过添加了不同含量的锂云母，探究了其对莫来石–刚玉质复相陶瓷的性能影响。利用X射线衍射仪、扫描电子显微镜对陶瓷的物相组成和形貌进行分析，研究锂云母的含量、烧结温度等对陶瓷力学性能的影响。结果表明：锂云母的加入可降低陶瓷烧结温度，提高其力学性能，当添加质量分数为10%的锂云母、烧结温度为950℃，制得莫来石–刚玉质复相陶瓷的力学性能较好，满足建筑陶瓷材料应用领域及建筑砖使用要求，其物相组成为刚玉、莫来石、石英、赤铁矿、金红石及玻璃相，体积密度为1.75 g/cm³，导热系数为0.447 W/(m·K)，收缩率为5.47%，常温抗压强度为74.87 MPa，在建筑陶瓷材料等领域具有广泛的应用前景。     

Machinability of fluormica glass-ceramics of high mica volume fraction

The high Machinability of Mica glass-ceramics is due to its unique microstructure. This study investigated barium fluormica glass-ceramics, with reference to parameters, which determine the microstructure that governs Hardness and machinability and explore the validity of Baik’s model for high mica Volume Fractions. Barium fluormica glasses were synthesized and casted into rods then heat-treated at 1175 °C and 1200 °C for various times. Glass-ceramics were characterized using DSC, SEM, Vickers microhardness and machinability test. “House of Cards” microstructure was successfully obtained upon heat treatment and was associated with an increase in Volume Fraction and Aspect Ratio of crystals. The Volume Fraction was almost identical for all the samples. However, crystal length and width increased with increasing holding time. Hardness and machinability forces decreased with increasing the Aspect Ratio and Effective Crystallinity. Hardness and Machinability data agreed well with Baik’s data and extend the validity of Baik’s model to much higher Volume Fractions.     

The effect of barium content on the crystallization and microhardness of barium fluormica glass-ceramics

Mica glass-ceramics are easily machined due to their “House-of-Cards” microstructure. Barium fluormica glass-ceramics were developed and indicated good mechanical properties. This work studies the effect of varying barium content on the crystallization and microhardness of mica glass-ceramics. Four glasses were produced with different baria contents, then converted to mica glass-ceramics using a two-step heat treatment. They were characterized using Differential Scanning Calorimetry [DSC], X-ray Diffraction [XRD], Scanning electron microscopy [SEM] and Vickers microhardness. DSC showed some formulations indicated bulk crystallisation as the dominant mechanism. XRD showed the crystallization of Barium fluorphlogopite in all the compositions with minor secondary phases. SEM showed the formation of “House-of-Cards” microstructures and with an increase in BaO content, a decrease in contrast was observed in back scattered mode. Exceptionally low hardness values (<2 GPa) were obtained for longer heat treatments/holding times and are related to the well-developed house-of-cards microstructures formed.     

氟云母加入量对可加工氟闪石玻璃陶瓷反应析晶的影响

用X射线衍射、扫描电镜研究了不同加入量氟云母晶体的钠钙玻璃粉末在烧结过程中的反应析晶.结果表明:氟云母加入量小于20%(质量分数,下同)时,反应析晶形成透辉石;加入40%时形成氟闪石;加入60%时氟闪石和氟云母共存;加入80%时大部分氟云母未反应,只有少量氟闪石形成.提出氟云母向透辉石和氟闪石转变的晶体学模型来解释上述结果.烧结过程中,玻璃中的Na2O和CaO通过扩散进入氟云母晶体,导致硅氧四面体平面网断裂,转变成链状结构.反应析晶的最终产物与进入氟云母晶体中的氧含量有关,决定于最终晶体中O和Si的摩尔比.     

可加工陶瓷材料研究进展

介绍了国内外可加工陶瓷材料的研究现状,包括可加工玻璃陶瓷、可加工Ti_3SiC_2陶瓷、可加工SiC、Si_3N_4陶瓷、可加工复相陶瓷以及可加工陶瓷的各种加工技术,并对其发展趋势进行了展望。     

Preparation of Machinable Fluoramphibole Glass–Ceramics from Soda-Lime Glass and Fluormica

A novel route, directly mixing fluormica crystals with recycled soda-lime glass powder and then sintering, is proposed to fabricate machinable fluoramphibole glass–ceramics. The effect of fluormica addition on the sinterability, reactive crystallization behavior, strength, and machinability of the material was investigated. The relative densities of the glass–ceramics decreased with increasing fluormica content. An interaction between fluormica crystals and glass powder occurred during the sintering process. Diopside was formed in the glass–ceramics with 20 wt% fluormica, and fluorrichterite was formed in the glass–ceramics with more than 30 wt% fluormica. Machinability and strength of the glass–ceramics were improved with increasing crystalline phase content.     

不同氧化物(ZnO、Fe2O3、ZrO2)对SiO2-MgO-Al2O3-F玻璃陶瓷析晶的影响

应用扫描电子显微镜（SEM）和X射线衍射（XRD）等技术研究了ZnO、Fe2O3、ZrO2对SiO2-MgO-Al2O3-F玻璃陶瓷析晶组织形态的影响。结果表明：在所研究的玻璃体系中，不同氧化物加入后都促进了主晶相氟云母晶体的析出。但不同氧化物对析出晶体的形貌影响不同，当基础玻璃中添加了质量分数为2．0％的ZnO时，形成片状氟云母晶体和颗粒状莫来石相；当添加2．0％的Fe2O3后，大量均匀细小的针状氟云母晶体和块状FeFeO4晶体析出；而当添加4．0％的ZrO2后，除了氟云母和莫来石析出外，粒状ZrO2晶体夹杂在氟云母晶体之间均匀析出。     

工业固体废弃物作为合成微晶玻璃原料的开发和利用

概述了以工业废渣、尾矿尾砂、冶炼炉渣等工业固体废弃物为原料制备微晶玻璃的研究现状.对固体废弃物作为制备微晶玻璃原料的前景进行了展望,指出利用页岩残渣制备微晶玻璃的研究将开辟页岩残渣综合利用的新途径.     

酸洗硼镁渣微晶玻璃的研究

对以酸洗硼镁渣为主要原料制造微晶玻璃进行了研究,利用ＤＴＡ,ＸＲＤ,ＳＥＭ等手段研究了组成对析晶性能的影响,并测试了部分性能。结果表明,在酸洗硼镁渣利用率达６０％,添加适量的长石,方解石等原料情况下,可获得主晶相为透辉石和透辉石与钙长石固溶体的性能良好的微晶玻璃。     

TiO2作为晶核剂的云母微晶玻璃的分相与析晶

Phase separation and crystallization behaviors of fluormica glass-ceramic with the nualeation agent of TiO2 were investigated by means of XRD,SEM,DTA and EDX.The results indieate that,during the heat treatment process,phase separation oceurred,i. c, adroplet phase rich in titanium appeared in the continual matrix glass.In the droplet phase , magnesium titanate crystals initially precipitated.Basing on these initial titanate erystals,flucrophlogopitc nuelei formed and grew.Thus a kind of fluormica glass-ceramic was prepared.