SiC加入量和粒度对耐火浇注料性能的影响

以特级矾土骨料、氧化铝微粉、二氧化硅微粉、刚玉细粉、SiC和纯铝酸钙水泥为主要原料,研究了SiC加入量和粒度对耐火浇注料性能的影响。研究发现,在浇注料基质内加入6％的150目SiC,可以改善耐火浇注料的抗热震稳定性。     

SiC粉和棕刚玉粉粒度对炮泥性能的影响

以铝矾土、SiC粉、棕刚玉粉、焦炭、黏土等为原料,以焦油为结合剂,制备了炮泥试样,研究了SiC粉和棕刚玉粉的粒度对炮泥性能的影响。研究结果表明:随着SiC粉和棕刚玉粉粒度的增大,试样的马夏值减小,可塑性增强,200℃烘干后强度增大,1 450℃烧后强度减小;综合考虑SiC粉、棕刚玉粉粒度对炮泥塑性和强度的影响,选择粒度为4.89μm的SiC粉和粒度为4.14μm的棕刚玉粉较为适宜。     

粒度组成对高铝质低水泥浇注料性能的影响

以三聚磷酸钠为分散剂,以特级高铝矾土熟料为骨料和细粉,加入5%的SiO2微粉,骨料的配方选取合适的粒度分布系数(q值取0.26～0.30)制备试样.分别测定了在烘干(110 ℃×24 h)和中温处理(1 100 ℃×3 h)后试样的显气孔率、体积密度、抗折强度和耐压强度.结果表明,粒度组成对浇注料性能有显著的影响,对于该试验所选用的耐火原料,当q值取0.28时,浇注料的性能最好,尤其是中温处理后试样的强度增加显著.     

基体改性对SiC/SiC复合材料高温抗氧化性能的影响

采用先驱体浸渍-裂解工艺结合三种基体改性方式制备了SiC/SiC复合材料,通过形貌分析和力学性能测试,分析了基体改性对Si C/SiC复合材料高温抗氧化性能的影响。研究表明,经1200℃静态空气氧化100h后,三种基体改性的复合材料弯曲强度几乎没有下降,氧化200h后,弯曲强度保留率均可达到80%;氧化300h后,复合材料内部结构没有氧化现象,表面区域界面层的氧化程度降低。改性基体中的B元素氧化生成液相封填SiC涂层表面,延缓了SiC涂层的氧化进程,并阻止氧化介质进入复合材料内部,保护纤维和界面层,从而使SiC/SiC复合材料的长时静态高温抗氧化性能明显提高。     

粒度分布对宁东羊场湾煤制水煤浆性能的影响

为了提高宁东地区煤的成浆性能,通过调整煤粉成浆的粒度分布,研究了粒度分布对水煤浆成浆性能的影响。实验证明,采用双峰级配,且小于200目煤粉占50%时,制得的水煤浆质量分数达到61.7%,比甲醇厂实际工况中水煤浆最大质量分数提高3%。     

塑料助剂的粒度对塑料性能的影响

塑料助剂的粒度对塑料性能的影响王文广（长白集团进出口公司１１００４１）邵文君（鞍山金成塑料制品有限公司１１４０１１）胡箫（大连理工大学机械厂１１６０２３）１前言传统上,人们研究塑料助剂时,只注重助剂的化学组成对塑料性能的影响,而未注意助剂的物理形态,...     

粉体粒度对涂料性能的影响

介绍了粉体粒度对粉体自身、涂料及涂层性能的影响。指出目前微细化粉体逐渐成为涂料用粉体的主流,随着涂料品种的多样化发展,会有更多的纳米级粉体在涂料中得到应用。     

金刚石粒度对金刚石锯片性能的影响

根据锯切过程中锯片的金刚石粒度与切屑厚度之关系论述金刚石粒度对锯片性能的影响,主要包括锯切率、使用寿命、功率消耗.在关于金刚石粒度的表示方式中,指出单纯以目数表示金刚石粒度的局限性和以每克拉颗粒数(PPC)表示金刚石粒度的重要性.     

PCS的沉淀分级对SiC纤维性能的影响

研究了聚碳硅烷(PCS)的沉淀分级对碳化硅(SiC)纤维性能的影响。结果表明，沉淀分级可以使PCS的相对分子质量分布变窄，减少低分子部分的含量，虽然纺丝较为困难，但能提高SiC纤维的力学性能，这对于终极目标为提高纤维力学性能的SiC纤维的制备过程来说，沉淀分级是一种有效提高纤维性能的手段。     

颗粒级配对硅碳棒热端密度及性能的影响

采取相同的塑化剂配方和成型压力,研究了碳化硅颗粒级配(粗粉800～1600μm,中粉100μm,细粉1.2～14μm)对硅碳棒热端挤出密度以及电性能和抗氧化性的影响。结果表明:1)在硅碳棒热端塑性挤出工艺中,当粗、中粉之和与细粉(含塑化剂)的体积比为7:5时,坯体的挤出成型密度最高;2)在硅碳棒热端的挤出成型中,粗、细粉的粒径都对坯体密度有较大的影响,当粗粉为1.4mm占40%(体积分数,下同)和600μm占25%,中粉为100μm占10%,细粉为5μm占25%时,制得坯体的密度高达2.56g.cm-3;3)硅碳棒热端的电阻率与碳化硅颗粒烧结颈的多少和粗细有很大关系,合适的级配能使硅碳棒中的碳化硅颗粒基本烧成一体,减少其颗粒之间的界面,从而提高制品的导电性能和抗氧化性能。     

添加物对高铝砖结构和性能的影响

研究了添加少量锆英石、红柱石、电熔刚玉、Ａｌ２Ｏ３微粉等对高铝砖（Ａｌ２Ｏ３＞７５％）结构和性能的影响。为生产高质量的高铝砖提供有益的指导     

高强度刚玉碳化硅浇注料的研制

以棕刚玉和碳化硅为主要原料、铝酸钙水泥为结合剂,制备出了一种高强度的刚玉碳化硅浇注料。通过优化颗粒级配,调整水泥和复合微粉的加入量,测定试样在各种因素影响下的常温和高温强度。结果表明,研制出的刚玉碳化硅浇注料既具有较高的常温强度,又具有很高的高温强度。     

Ballistic testing of surface‐treated alumina and silicon carbide with improved adhesive bond strength

The laser treatment of ceramics can lead to increased concentrations of hydroxyl ions on the surface, resulting in improved adhesive bond strength in quasi‐static tests. Whether the improvement can be translated to armor applications is investigated here. The ballistic testing of composite‐backed, surface‐treated, and nontreated “control” alumina and silicon carbide panels was undertaken. The failure locus of the ceramic to adhesive/composite joint and the qualitative degree of damage were assessed. Laser surface‐treated samples performed better than control samples, with silicon carbide moving from single shot to multi‐shot capability, thus giving significant advantages for the deployment of these materials.     

高铝质制品在硫化碱回转炉上的使用

针对硫化碱（Na2S）回转炉的使用条件,重点分析了Ⅰ等高铝砖的损毁原因。采用以高铝矾土为主要原料生产的新产品,解决了炸裂与剥落问题,且抗侵蚀性也有所提高。     

氧氮化硅结合碳化硅制品的生产与使用

以工业用黑色碳化硅砂、硅粉为主要原料，研制出了导热性能优良、抗热震性好、耐高温、耐侵蚀及耐磨损，且生产工艺较简单、成本较低的氧氮化硅结合的碳化硅制品．该产品已广泛应用于冶金炉、化工设备及发电用锅炉的内衬，并取得了较满意的效果。     

Effect of grain growth on the thermal conductivity of liquid-phase sintered silicon carbide ceramics

The effect of grain growth on the thermal conductivity of SiC ceramics sintered with 3 vol% equimolar Gd₂O₃-Y₂O₃ was investigated. During prolonged sintering at 2000 °C in an argon or nitrogen atmosphere, the β → α phase transformation, grain growth, and reduction in lattice oxygen content occurs in the ceramics. The effects of these parameters on the thermal conductivity of liquid-phase sintered SiC ceramics were investigated. The results suggest that (1) grain growth achieved by prolonged sintering at 2000 °C accompanies the decrease of lattice oxygen content and the occurrence of the β → α phase transformation; (2) the reduction of lattice oxygen content plays the most important role in enhancing the thermal conductivity; and (3) the thermal conductivity of the SiC ceramic was insensitive to the occurrence of the β → α phase transformation. The highest thermal conductivity obtained was 225 W(m K)⁻¹ after 12 h sintering at 2000 °C under an applied pressure of 40 MPa in argon.     

Effect of grain size and amount of zirconia on the physical and mechanical properties and the wear resistance of zirconia-toughened alumina

The effects of the ZrO₂ content and the particle size of ZrO₂ powders on the microstructure, phase composition, physical and mechanical properties, and the abrasion wear resistance of advanced Al₂O₃ ceramics and zirconia-toughened alumina (ZTA) composites containing 0 to 30 mass% yttria-stabilised zirconia (YSZ) were investigated. The composite with a ZTA content of 30 mass% of ZrO₂ exhibited the greatest resistance to abrasion wear. α-Al₂O₃ reflex broadening (hkl = 113) as a result of the microstresses in the Al₂O₃ crystal lattice during sandblasting decreased with increasing ZrO₂ amount, where the ZrO₂ particles located along the grain boundaries of Al₂O₃, hindering their growth and deformation. The use of nanodispersed ZrO₂ powder produced by the plasma chemical technique led to a 1.5-fold increase in wear resistance in the resultant ZTA ceramic.     

碳化硅对低水泥结合氧化铝空心球浇注料性能的影响

以3种粒度级别的氧化铝和氧化铝微粉为原料,以铝酸钙水泥为结合剂,采用振动浇注成型的方法制备了低水泥结合氧化铝空心球浇注料。利用耐火材料检测设备和扫描电子显微镜(SEM)研究了加入碳化硅对低水泥氧化铝空心球浇注料性能及微观结构的影响。研究结果表明,适量加入碳化硅对提高该种浇注料的体积密度、常温耐压强度和热震稳定性有利。     

Effect of grain size on corrosion of high purity aluminium

A complete understanding of how grain refinement, grain size, and processing affect the corrosion resistance of different alloys has not yet been fully developed. Determining a definitive ‘grain size–corrosion resistance’ relationship, if one exists, is inherently complex as the processing needed to achieve grain refinement also imparts other changes to the microstructure (such as texture, internal stress, and impurity segregation). This work evaluates how variation in grain size and processing impact the corrosion resistance of high purity aluminium. Aluminium samples with a range of grain sizes, from ∼100 μm to ∼2000 μm, were produced using different processing routes, including cold rolling, cryo rolling, equal channel angular pressing, and surface mechanical attrition treatment. Evaluation of all the samples studied revealed a tendency for corrosion rate to decrease as grain size decreases. This suggests that a Hall–Petch type relationship may exist for corrosion rate and grain size. This phenomenon, discussed in the context of grain refinement and processing, reveals several interesting and fundamental relationships.