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Effects of combined addition of Y and Ca on microstructure and mechanical properties of die casting AZ91 alloy WANG Feng(王 峰), WANG Yue(王 越), MAO Ping-li(毛萍丽), YU Bao-yi(于宝义), GUO Quan... AZ91 alloy with combined addition of Y and Ca were investigated by optical microscopy, scanning electronic microscopy, X-ray diffractometry and mechanical property test. The results show......
素Be和Ca的氧化方式并不相同.加入Be后 , Mg发生外氧化 , Be发生内氧化.加入Ca后 , Ca发生外氧化 , Mg发生内氧化 , 因此合金表面氧化膜的物相组成和元素分布也不相同 关键词: 铍;钙;镁合金;热力学; 中图分类号: TG14 收稿日期:1999-12-09 Effects of Be and Ca on surface...化行为以及具有保护作用的氧化膜的形成过程等问题, 有关文献中并未作深入分析. 本文作者对加入Be和Ca后合金在高温下生成的氧化膜进行了组成相分析和深度化学成分分析, 结合热力学原理对基体元素Mg和合金元素Be, Ca在两种合金中的氧化方式进行了讨论, 并用一种统一的氧化动力学模型分析了氧化膜的形成. 1 实验方法 用纯铝, 纯镁, 纯锌, 纯钙, Al-3Be合金等配制成......
点实验室,南昌 330013) 摘要:在含15 g/L食品添加剂植酸的基本溶液中,分别加入乙酸钙,氧化钙,磷酸二氢钙,甘油磷酸钙,EDTA-Ca 5种钙盐以及氢氧化钾,研究钙盐种类和氢氧化钾浓度对钛合金微弧氧化膜表面形貌及成分的影响.采用扫描电子显微镜(SEM),X射线能谱仪(EDS),X射线衍射仪(XRD)和傅里叶红外光谱仪(FT-IR)表征氧化膜的表面形貌,成分和结构.结果表明:钙盐能显著提高氧化膜中磷含量,且氧化钙,磷酸二氢钙和EDTA-Ca能较大程度地提高氧化膜中的钙含量;氢氧化钾浓度越高,氧化膜中的钙含量越高.钙盐和氢氧化钾均能增大氧化膜表面的微孔直径. 关键词:钛合金;微弧氧化;电解质;钙盐;氢氧化钾 中图分类号:TG146.2+3  ......
the original 4 to 3. As shown in Table 8, the population of O-Na bond is 0.03, which is lower than that of O-Ca bond. In addition, the O-Na bond has a larger atomic distance than O-Ca bond... that the covalency of O-Na bond in Na2O-doped 12CaO·7Al2O3 cell is weaker than those of O-Ca and O-Al bonds. The free energy of the unit cell increases because of Na2O doping, which results......
; Abstract: The effects of Ca and Sr addition on the microstructure and creep properties of Mg-4Al-2Sn.... The microstructure of the Mg-4Al-2Sn alloy showed dendritic α-Mg, Mg17Al12 and Mg2Sn phases. The latter two phases precipitated along the grain boundaries. The addition of Ca and Sr resulted......
) where the Ksp values of Ca(OH)2, Mg(OH)2 and Mn(OH)2 are 10-5.26, 10-11.25 and 10-12.72, respectively [8], pKW refers to the negative logarithm of the ionic activity product constant of water and its... to be removed. In addition, other chemicals in the experiments such as ammonium bicarbonate, ammonia water (28%) and barium chloride were analytical reagent grade and de-ionized (DI) water was used in dissolution......
微量Ca对镁合金组织及性能的影响佟坤,吴晓英,周梦雨,郑旭烟合肥工业大学材料科学与工程学院摘 要:研究了微量Ca对ZK60镁合金组织,力学性能和腐蚀性能的影响.结果表明:当ZK60合金中加入适量Ca(0.05%~0.40%)时,Ca主要固溶于基体中,合金中几乎无Ca相生成;随Ca含量增加,合金的力学性能和耐蚀性提高,当Ca质量分数为0.15%时,T6态合金的抗拉强度和伸长率均达到最大值282 MPa和16.8%,室温拉伸断口主要由韧窝组成,呈韧性断裂,且腐蚀速率也显著降低.其原因主要是由于适量Ca促进了MgZn,MgZn2的析出,晶界结构较为连续和紧密,同时使镁合金的腐蚀电位升高,从而阻碍了镁合金的腐蚀,提高了镁合金的综合性能.关键词:镁合金;钙;显微组织;力学性能;耐腐蚀性能;......
Influences of Ca and Y Addition on the Microstructure and Corrosion Resistance of Vacuum Die-Cast AZ91 AlloyFeng Wang1,Jibao Li1,Jing Liu1,Dan Lv2,Pingli Mao1,Zheng Liu11. School of Material Science... results indicate that the Ca or Ca and Y additions refined the microstructure and decreased the amount of Mg17Al12 phase on grain boundaries in the alloys.Meanwhile,the addition of Ca and Y led......
E级船板钢质量和钢包喂钙硅线模型的研究[D]. 北京: 北京科技大学冶金与生态工程学院, 2007: 69-70. LIU Danmei. Research on the quality of E grade hull structural steel and the model of Ca-Si wire addition in ladle[D]. Beijing: University...DOI: 10.11817/j.issn.1672-7207.2016.06.005 钢包钙处理工艺中钙汽化过程的数值模拟 王顺玺,张炯明,宋炜,王博,白敦敏 (北京科技大学 钢铁冶金新技术国家重点实验室,北京,100083) 摘要:根据钙处理过程中汽化速率的变化特点,结合实际喂线工艺参数,将钙处理工艺分为喂线阶段和弱搅静置2个阶段,建立钢包钙汽化过程的数学模型.利用大型商业软件......
,并存在沿着不同方向生长的多晶与单晶共存结构;在最佳浸出条件下,浸出率高达98.41%,优于同条件下12CaO·7Al2O3的浸出率;浸出后Al和S元素分别以与的形式存在于浸出液中,Ca以CaCO3的形式存在于浸出渣中. 关键词:硫铝酸钙;合成;氧化铝;浸出 (Edited by Bing YANG) Foundation item: Project (E2016208107) supported..., and there is no aluminiferous compound phase. The main phase of leaching residue is CaCO3. In addition, CaSO4 is also not found in the slag. Therefore, the equation of the alumina leaching of C4A3S......