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are developed due to the HABs, termination migration and Ostwald ripening. The present results suggest that a higher strain rate and a larger height reduction are necessary before annealing to achieve... thermal grooving by penetration of β phase. As a result, static globularization by grooving is weakened as annealing time increases. Meanwhile, termination migration and Ostwald ripening become more......
was calculated and thus the variation of the critical nucleus sizes was determined based on the Ostwald ripening formula. The results show that the Al(OH)3 solubility in sodium aluminate solution decreases..., then obtained a interfacial tension of (45±6) mJ/m2 and a critical nucleus size of (0.0012±0.0001) μm at 333 K by using the nucleation rate equation and the Ostwald ripening formula, respectively. ZHANG et al [12......
(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......
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......
, and finally are coarsened owing to Ostwald ripening. Key words: magnesium alloy; partial remelting; thixoforming; microstructure evolution; phase transformation; in-situ composite 1 Introduction... that the particle coarsening regime transfers from a severe regime to a mild regime after 30 min. The Ostwald ripening is a process in which a semisolid system lowers its interfacial energy by reducing its......
the Ostwald ripening mechanism, and adding Al element into Mg-7Zn alloy results in a decrease of coarsening rate of solid particles in semi-solid slurry, consequently, it can obtain the perfect semi...渐降低,而在后期处于固液平衡阶段,固相率的变化不明显;同时,固相颗粒粗化符合Ostwald熟化机制,且Al元素的加入减小了初生固相颗粒的粗化速率,从而在较宽的保温时间范围内可获得细小圆整的固相颗粒. 关键词:Al含量;Mg-Zn-Al合金;半固态;粗化 中图法分类号:TG 146.22  ......
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......