本文選題：頂部籽晶熔融織構(gòu)法 + 單疇GdBCO超導(dǎo)塊材��； 參考：《陜西師范大學(xué)》2010年碩士論文

【摘要】： 頂部籽晶熔融織構(gòu)法(TSMTG)是制備釔系高溫超導(dǎo)塊材的重要技術(shù)之一。在釔系超導(dǎo)材料中,GdBCO超導(dǎo)體具有較高的臨界溫度、較大的無阻載流能力和較強(qiáng)的磁通捕獲能力,因而在超導(dǎo)電機(jī)、超導(dǎo)磁懸浮列車、磁浮軸承、永磁體、儲能飛輪等方面都具有巨大的應(yīng)用價值。 本文采用固相燒結(jié)法制備出比較純的初始粉體,采用TSMTG工藝制各出摻雜不同BaCuO2 (Gd011)含量的GdBCO單疇超導(dǎo)塊材,并對該類超導(dǎo)塊材的微觀結(jié)構(gòu)和磁懸浮力等性能進(jìn)行了分析；其次,通過在GdBa2Cu3O7-δ(Gd123)初始粉體中摻雜不同含量的Y2O3粉體,制備出了系列(Gd, Y)BCO超導(dǎo)塊材,在對其宏觀形貌,微觀結(jié)構(gòu)和磁懸浮力性能進(jìn)行分析的基礎(chǔ)上,研究了工藝參數(shù)對超導(dǎo)塊材形貌和性能的影響。 在制備GdBCO超導(dǎo)體的過程中,需要用到GdBa2Cu3O7-δ(Gd123)、Gd2BaCuO5(Gd211)和BaCuO2 (Gd011)等初始粉體。這些粉體均采用多次研磨多次燒結(jié)的工藝,三種粉體的燒結(jié)溫度分別為940℃,920℃,910℃。 研究了BaCuO2添加對TSMTG法單疇GdBCO塊材的生長形貌、微觀結(jié)構(gòu)以及磁懸浮力性能的影響。在固定Gd123與Gd211摩爾比為1：0.4時,當(dāng)Gd011摻雜量在0-0.5mol范圍內(nèi)時,Gd011的摻雜對其表面形貌影響不大,均可制備出單疇GdBCO塊材。對整個組分進(jìn)行的微觀結(jié)構(gòu)分析結(jié)果表明：隨著Gd011摻雜比例的增加,Gd211粒子的尺寸在逐漸地減小。這是由于過量Gd011致使Gd211在液相中溶解的結(jié)果。另外,我們研究了Gd211粒子在準(zhǔn)單疇GdBCO超導(dǎo)塊材中的分布。對摻雜Gd011為0.2mol的準(zhǔn)單疇樣品分析結(jié)果表明,Gd211粒子在整個樣品中分布都是不均勻的。對該系列超導(dǎo)塊材磁懸浮力測試的結(jié)果表明,Gd011的含量對GdBCO超導(dǎo)體的磁懸浮力有明顯影響,在固定Gd123與Gd211摩爾比為1：0.4時,摻雜BaCuO2的最佳比例約為0.2mol。 研究了Y2O3添加對TSMTG法(Gd, Y)BCO超導(dǎo)塊材的生長形貌、微觀結(jié)構(gòu)以及磁懸浮力性能的影響。當(dāng)在Gd123初始粉體中添加Y2O3質(zhì)量分?jǐn)?shù)較小時,疇區(qū)長滿整個樣品；當(dāng)兩者質(zhì)量比例超過100：4時,隨著添加的Y2O3質(zhì)量的增加,樣品表面所形成的單疇區(qū)域面積逐漸減��；當(dāng)兩者質(zhì)量比例超過100：15時,樣品完全停止生長。對其生長前沿成份分析結(jié)果表明,成份偏析是導(dǎo)致晶體生長停止的主要原因。對摻雜Y2O3粉體的樣品,隨著摻雜量的增加,鑲嵌在樣品中的RE211粒子密度逐漸增加,同時RE123相含量逐漸減少。磁懸浮力測試結(jié)果表明,Y2O3的含量對(Gd, Y)BCO超導(dǎo)塊的磁懸浮力有明顯影響,其最佳添加質(zhì)量比為Gd123：Y2O3=100：4。溫度參數(shù)的選擇對(Gd, Y)BCO超導(dǎo)塊形貌和性能的影響也很大,最高融化溫度過高過低都不好,通過多次調(diào)整得到最佳熔化溫度為1070℃。生長溫區(qū)的選擇直接關(guān)系到樣品生長的好壞,通過四組不同的生長溫區(qū)試驗(yàn)得到相對最佳生長溫區(qū)。
[Abstract]:Top seed melt texture method (TSMTG) is one of the important techniques for preparing yttrium high temperature superconducting bulk materials. In yttrium superconducting materials, GdBCO superconductors have higher critical temperature, larger unstoppable current-carrying capacity and stronger flux trapping ability, so they are used in superconducting motors, superconducting maglev trains, maglev bearings, permanent magnets, etc. The energy storage flywheel has great application value. In this paper, the relatively pure initial powders were prepared by solid-state sintering, and GdBCO single domain superconducting bulk materials doped with different BaCuO2 Gd011) were prepared by TSMTG process. The microstructure and magnetic suspending force of these superconducting blocks were analyzed. A series of Gd and Y)BCO superconducting bulk materials were prepared by doping different contents of Y2O3 powders into the initial GdBa2Cu3O7- 未 Gd123) powders. Based on the analysis of their macroscopic morphology, microstructure and magnetic suspended buoyancy properties, a series of superconducting bulk materials of GdBa2Cu3O7- 未 Gd123 were prepared. The effect of process parameters on the morphology and properties of superconducting bulk was studied. In the preparation of GdBCO superconductors, the initial powders, such as GdBa2Cu3O7- 未 (Gd123O5 (Gd2CuO5) Gd211) and BaCuO2 (Gd011), are needed. The sintering temperature of the three kinds of powders is 940 鈩，

本文編號：1863507