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Cu0.3Co2.7O4 microspheres consist of single-crystalline nanocubes with the diameter of about 20 nm. The formation mechanism of hollow Cu0.3Co2.7O4 microspheres is suggested as Ostwald ripening in a solid... on the detailed time-dependent crystallization research, it is suggested that Ostwald ripening in a solid-solution-solid process plays an important role in the formation mechanism of hollow Cu0.3Co2.7O4......
at the solid/liquid two-phase region. This would be attributed to the Ostwald type ripening and coalescence between primary α-Mg phases. The cooling rate below to the solid/liquid two-phase region, Mn......
(SEM),能谱分析(EDS)及差热分析(DSC/TG)对Ni/TiH2复合粉末进行表征,探索Ni镀层的生长及作用机理,建立镀层在粉末表面的生长模型.结果表明:施镀温度为85℃时Ni/TiH2复合粉末表面Ni层包覆完整,镀层均匀致密,Ni层厚度约为1.0~2.0μm;施镀温度低于65℃时施镀几乎无法进行,而施镀温度高于95℃时,镀层很不均匀,且容易脱落;镀层的生长机制遵循奥斯特瓦尔德(Ostwald ripening)机制;与包覆前TiH2粉末相比,Ni/TiH2复合粉末的释氢反应开始温度由450℃上升至540℃.包覆层可降低TiH2粉末和熔融铝的温度梯度,从而推迟开始释氢的时间.关键词:化学镀;Ni/TiH2复合粉末;形核长大机制;释氢性能;......
of their morphology, size, and distribution. After 30 min of ovulation at 1573 K, the percentage of Mn S inclusions larger than 3 μm decreased from 50.5% to 3.0%. After a 3 h soaking period, Ostwald ripening......
) rather than by the well-known Ostwald ripening mechanism. In other areas, the partial dissolu-tion of the γ’ precipitates began to occur, spreading gradually from dendrite cores to interdendritic......
表面活性剂对TiO2纳米晶体生长动力学的影响展红全,江向平,李小红,朱棉霞,罗志云景德镇陶瓷学院材料科学与工程学院江西省先进陶瓷材料重点实验室摘 要:采用水热法,分别以丙二酸,正丁醇,乙二胺为表面活性剂,研究3种体系下TiO2纳米晶体的生长过程.XRD结果显示3种体系下主要产物为锐钛矿TiO2;TEM和HRTEM结果表明在不同的生长阶段,纳米晶体的生长结构特点明显不同.分别采用定向生长理论(Orientation attachment,OA),弗兰克尔收缩理论(Frenkel shrinking,SH),奥斯特瓦尔德熟化理论(Ostwald ripening,OR)对3种体系下的晶体生长进行理论模拟,结果发现在丙二酸,乙二胺体系下晶体生长分为3个阶段:定向聚集生长,颗粒收缩,奥斯特瓦尔德熟化,且乙二胺......
inclusion were based on the experiments.Thus,a mathematical model was developed to investigate the nucleation,Ostwald ripening and collision-growth of magnesia inclusion in the molten steel.Numerical......
suppress the dissolution, Ostwald ripening and growth behaviours of TiB2 particles. Key words: TiB2 particles; kinetic behaviour; grain refinement; aluminium alloy 1 Introduction To achieve a fine equiaxed... particles respectively vary with time according to ∝t and N-1μt (see the inset in Fig. 4(c)), indicating that the TiB2 particles coarsen through Ostwald ripening [30]. During the cooling of melt......
continuously increases and the degree of spheroidization also improves. Coalescence mechanism is dominant when reheated at 595 °C and Ostwald ripening mechanism is dominant when reheated at 615 °C......
time resulted in grain coarsening and the improvement in degree of spheroidization.The coarsening behaviour of solid grains in the semi-solid state obeyed Ostwald ripening mechanism.The coarsening rate......