微量添加剂对6063铝合金晶粒细化及力学性能的影响

研究了微量稀土和Al-Ti-B添加剂对6063铝合金的晶粒尺寸和力学性能的影响。结果表明：微量稀土和Al-Ti-B复合作用后的效果更明显，6063铝合金的晶粒得到显著细化，抗拉强度和延仲率得到很大的提高。     

链状纳米碳酸钙的制备

用间歇鼓泡碳化法制备了链状纳米CaCO3,用pH计和电导仪对碳化反应跟踪检测 ,对其形成机理进行了分析 ,实现了对链状CaCO3的粒度控制。考察了碳化反应过程中pH值、电导率和反应物质量分数、反应温度、CO2 气体流等因素对产品粒径和形态的影响。结果表明 ,碳化反应过程中 pH值和电导率都有一个快速下降阶段。其中电导率有两个下降回复过程。Ca(OH) 2 质量分数、CO2 流量的增大、反应温度升高都会使反应速率和晶核生长速率变大。反应温度控制在 30℃左右 ,Ca(OH) 2 质量分数为 1 0 %左右 ,在一定范围内CO2 流量越大所得晶体结构越好     

分布式存储环境下的加性Schwarz方法

引言 区域分裂方法起源于古老的schwarz交替方法[l].八十年代末期,法国数学家P.L.LionS提出了schwarz交替方法的投影解释[2一4],使得人们对schwarz交替方法有了全新的认识,为其进一步发展奠定了理论基础.由于并行计算环境的逐渐成熟以及预处理技术的兴起和大规模科学计算的需要,由严格串行的scliwarz交替方法发展了多种可完全并行的     

新型脱硅剂合成及脱硅反应的热力学研究

针对亚熔盐氧化铝流程中二氧化硅脱除的问题,提出采用钙铁榴石、水合碳铁酸钙和水合硫铁酸钙进行高浓环境介质分离;采用氧化物组成计算方法对此类化合物的Gibbs自由能进行了计算,在此基础上对脱硅剂合成反应进行了热力学研究;确定了不同脱硅剂的脱硅产物及其Gibbs自由能,对三种脱硅剂的脱硅能力进行对比,选择了最优脱硅剂。     

添加剂对多孔陶瓷显气孔率的影响

采用硅粉,碳粉,尿素以及氧化铝,氧化钇为原料,利用常压烧结法制备了氮化硅多孔陶瓷,并着重研究了添加剂对氮化硅多孔陶瓷显气孔率的影响,得出氮化硅多孔陶瓷的显气孔率随着碳粉或尿素含量的增加而增大,且碳粉的造孔作用优于尿素。     

冷喷涂制备高熵合金的研究进展

高熵合金是近年来一种突破传统合金设计理念的新型多主元合金材料,在抗压强度、硬度、热稳定性、耐磨性、耐腐蚀性等方面具有显著优于常规金属材料的特质.冷喷涂作为一种固态沉积技术,在高性能涂层制备、零件修复与再制造和零构件增材制造等方面受到国内外的广泛关注,为高熵合金的制备提供了一种新的途径.通过分析国内外冷喷涂制备高熵合金的...     

Influence of the build orientation on the fatigue strength of EOS maraging steel produced by additive metal machine

This paper presents a research dealing with the dependence of the fatigue strength of maraging steel parts, manufactured by direct selective laser sintering, on the production build orientation. Three sets of specimens have been manufactured according to the ISO 1143 Standard (2010) by EOSINT M280 additive manufacturing machine, with the following heat and mechanical treatments, in agreement with the recommendations by the material manufacturer and current literature. The expected outcomes are the Fatigue Limit values of the material and the maximum number of cycles observed at different stress levels for three different build orientations (three different angles, 0°, 45° and 90°, between the build direction and the longitudinal axis of the samples). The results have been processed and compared by statistical methods in order to determine the fatigue curves in the finite life domain and the fatigue limits, along with their confidence bands and intervals, and to investigate the significance of the build orientation factor.     

Direct Digital Manufacturing Industry Ascendant

The paper introduces the origin of the word of Direct Digital Manufacturing and other forms of address, and the working principles of Direct Digital Manufacturing technology and major types of the technology, hard- ware and software development, use of materials, applications, market growth and its development prospects. Focused presentations of Direct Digital Manufacturing （additive manufacturing） compared to traditional mechani- cal manufacturing industry in the use of prices, processing speed, reliability and cost advantages and characteris- tics. Particularly the significant challenges and competitiveness of Direct Digital Manufacturing technology in the processing of any complexity created directly the number of objects, internal structure and channel function, as well as the shape of the chassis components and structure of the matching and optimization.     

掺杂对镍铁尖晶石阳极材料烧结性能及电导率的影响

研究了La2O3,TiO2和MnO2氧化物添加剂及其添加量对镍铁尖晶石阳极材料烧结性能及电导率的影响,并探讨了其导电机理。试验结果表明,La2O3不能改善试样的烧结性能及电导率,而添加量为1％（质量比）的TiO2氧化物添加剂可显著提高试样的烧结性能及电导率。其高温导电机理为P-型半导体和n-型半导体结构混合影响的小极化子跳跃理论。MnO2偏析于晶界,反而降低了试样的高温电导率。     

核壳型氟硅改性丙烯酸酯乳液的合成与膜性能

采用核壳乳液聚合法合成了氟硅改性丙烯酸酯核壳乳液并对其膜性能进行了系统研究。通过交联基团改性、硅改性、氟改性等手段,合成了核直径约100 nm~150 nm、壳厚度约40 nm~60 nm的粒子大小较均匀的核壳乳液。结果表明,使用5%（质量分数）乙二醇丁醚作为乳液的成膜剂可以改善成膜附着力;通过γ-甲基丙烯酰氧基丙基三...