含非氧化物（SiC、Sialon）的矾土基浇注料的流变性和高温机械性能研究

【作者】 刘新红；

【导师】 钟香崇； 叶方保；

【作者基本信息】 郑州大学 ， 材料学， 2003， 硕士

【摘要】 本工作的主要研究对象是含非氧化物（SiC、Sialon）的矾土基浇注料，探讨了微粉、水泥等和非氧化物（SiC、Sialon）对矾土基浇注料流变性和高温机械性能的影响规律，目的是找出流变性较佳的浇注料组成和高温机械性能较高时非氧化物加入量。 研究工作主要分四个方面：（1）用NXS-11A型粘度仪测定基质的粘度、剪切应力-剪切速率的关系等来研究微粉、水泥、分散剂及SiC、Sialon等因素对矾土基浇注料基质流变性的影响；（2）用跳桌测定浇注料的流动值来评价微粉、水泥、颗粒形状、SiC及Sialon等对浇注料流动性的影响；（3）通过测定浇注料的常规物理性能指标—体积密度、气孔率、常温抗折强度（MOR）和常温耐压强度（CCS）等研究微粉、水泥、SiC及Sialon等对浇注料110℃×24h烘干后、1100℃×3h及1400℃×3h热处理后常规物理性能的影响；（4）分别用三点弯曲法和△T=1200℃水循环一次来研究微粉、SiC及Sialon等对浇注料高温机械性能（高温抗折强度HMOR、应力-应变关系、抗热震性TSR等）的影响。研究结果表明： （1）基质的流变类型属于宾汉姆流体；微粉和分散剂是影响基质流变性的决定性因素，SiO₂微粉能显著提高基质的流变性，Al₂O₃微粉和水泥对基质流变性略有负面影响；分散剂的分散效果为：FS-20＞P3＞C＞P’＞N＞B＞P₆＞G；在实验范围内，加入SiC有利于提高基质流变性，而加入Sialon则对基质流变性不利；325目／200目矾土细粉的比超过2／1时，基质粘度增加；刚玉细粉、镁砂和尖晶石细粉的加入对基质流变性影响较小。 （2）对浇注料而言，圆形颗粒有利于提高浇注料流动值；骨料／粉料=60／40时流动性较好；SiO₂微粉能显著提高浇注料流动值，加入Al₂O₃微粉则使浇注料流动值降低；加入SiC细粉有利于提高浇注料的流动值，而加入Sialon细粉则对浇注料流动性有负面影响。 （3）变化微粉和水泥比例时，随水泥在比例中的含量减少（即微粉含量增加，浇注料由LCC→ULCC→ZCC），1100℃×3h及1400℃×3h热处理后试样由微收缩到微膨胀，体积密度增加，气孔率降低，MOR，CCS增加。固定水泥和微粉加入量，在实验范围内，随SiC或Sialon细粉加入量增加，试样经中高温热处理后，线变化由微收缩到微膨胀，气孔率增加，体积密度降低，常温强度降低。郑州大学硕士学位论文 （4）a.当水泥含量为2%，改变A1203微粉/5102微粉（uf一A1203/uf-SIOZ）比值时，随5102微粉含量增加，试样的HMOR及TSR均提高。加入适量的非氧化物（siC、sialon），可提高矾土基浇注料的高温机械性能:当uf-A12o3厄f-sioZ=25275时，非氧化物加入量在0一8%范围内，随加入量增加，试样的HMOR和TSR都增加，且非氧化物含量为4%时，试样的HMOR达最大值;当uf一A1203/u f-Si02二75/25时，在0一16%范围内，随加入量增加，试样的HMOR和TSR增加，且非氧化物含量为16%时，试样的HMOR达最大值。 b.含8%非氧化物（siC、sialon）的试样:MOR.T曲线属于第一种类型，且Tm （MOR最大值的温度）为800℃或1000℃;临界温差△Tc为800℃;应力一应变研究结果表明在20荀oo℃为弹性范围，600-1000℃属于塑性范围，1000℃以上属于快速流动范围。c.根据XRD分析及化学反应方程式计算知，5102微粉含量高的试样中莫来石含量较高;根据SEM分析知，刚玉与莫来石形成较紧密的结构，加入适量的非氧化物（SIC、siaion）可以增强刚玉与莫来石形成的结构，有利于提高矾土基浇注料的高温机械性能。更多还原

【Abstract】 The mainly investigated object of this work is nonoxide (SiC, Sialon)-containing bauxite-based castables. The influences of ultra fine powders, cement etc. and nonoxide (SiC, Sialon) on rheology and thermo-mechanical properties of bauxite-based castables have been studied. The purpose of this work is to find the optimum castable composition and the optimum nonoxide (SiC,. Sialon) addition.This work can be divided into four parts: (1) The influences of ultra fine powders, cement, dispersants and SiC or Sialon fines on rheology of castable matrix have been studied using viscometer of model NXS-11 A. (2) The influences of ultra fine powders, cement, shape of aggregates, SiC or Sialon fines on castable flowability have been studied using flowing table. (3) The influences of ultra fine powders, cement and SiC or Sialon fines on room temperature properties (such as porosity, bulk density, MOR and CCS etc.) of castables after drying at 110℃ * 24h and heat treating at 1100℃*X 3h and 1400癈 X 3h have been studied. (4) The influences of microsilica/ultra fine alumina powders ratios, contents of SiC or Sialon fines on thermomechnical properties (such as HMOR, stress-strain relationship, TSR etc) of castables have been studied using conventional three point bend testing(HMOR, stress-strain relationship ) and 1200 癈 to water cycling(TSR).The results show that (1) the slurry with ultra fine powders is thixtropy and the rheological type of matrix is Bingham model; ultra fine powders and dispersants are the principal factors influencing matrix rheology, the effect of dispersants are FS-20>P3>C>P’ >N>B>P6>G and the effective dispersants have an optimal addition; microsilica can improve matrix rheology noticeably; ultra fine alumina and cement have slightly negative effect on matrix rheology; when the ratio of bauxite particles (-325mesh/-200mesh) is over 2/1, the viscosity of slurries begin to increase; the influence of Alumina, magnesia and spinel fines on matrix rheology are minor.(2) The round aggregates contribute to improving castables flow-ability; when the ratio of aggregates/matrix in the castable is 60/40, the value of the flowability is the highest; microsilica can noticeably improve flowability but ultra fine alumina and cement slightly reduce flowability of castables; the appropriate amount SiC fines addition can increase flowablity, but Sialon fines addition reduce flowablity of castables.(3) when the ratio of ultra fine powders/cement is varied, with decrease of the cement content (i.e. the ultra fine powders content is increased, LCC@ULCC@ZCC), the linear change of the specimens exhibites a little swell, the apparent porosity decreases, the bulk density slightly increases, MOR and CCS increase after heat treating at 1100℃*3h and 1400℃*3h; when the contents of cement and ultra fine powders are fixed, with increase of SiC and Sialon content in the matrix, the porosity increases, the bulk density, MOR and CCS decrease after heat treating at medium and high temperatures.(4) a. when the cement content is 2% and the ratio of microsilica /ultra fine alumina is varied, with increase of microsilica content, HMOR and TSR of the specimens are increased; when uf-Al2Od3/uf-SiO2 is 25/75 and the content of SiC or Sialon is in the range of 0-8% in the matrix, with increase of SiC or Sialon content, HMOR and TSR of the specimens are increased, and the maximum value of HMOR is specimen with 4% SiC or 8%Sialon; when uf-Al2O3/uf-SiO2 is 75/25 and the content of SiC or Sialon is in the range of 0-16%, with increase of SiC or Sialon content, HMOR and TSR are increased, and the maximum value of HMOR is specimen with 16% SiC or Sialon.b. MOR-T curves of the specimens with 8% SiC or Sialon belong to type I and their Tm is 800℃or 1000℃; the critical temperature difference (ATc) of the specimens is 800℃; the stress-strain relationship shows that the range of elastic deformation is 20-600℃,the range of plastic deformation is 600-1000℃ and the range of rapid flow range is 1000-1200℃.c. According to更多还原